extracted_text:
ФЕДЕРАЛЬНОЕ АГЕНТСТВО ПО ОБРАЗОВАНИЮ
Государственное
образовательное учреждение высшего профессионального образования
«ТОМСКИЙ ПОЛИТЕХНИЧЕСКИЙ УНИВЕРСИТЕТ»

ЮРГИНСКИЙ
ТЕХНОЛОГИЧЕСКИЙ ИНСТИТУТ

С.В.Гричин

АНГЛИЙСКИЙ
ДЛЯ СВАРЩИКОВ

Учебное
пособие

Издательство
ЮТИ ТПУ
Юрга
2007
         УДК
811 (Англ.)
         ББК
81 (Англ.)
         Г
82
          Гричин С.В.
Г 82 Английский для сварщиков: Учебное
пособие. – Юрга: Изд-во     ЮТИ ТПУ, 2007. – 181 с.
  Учебное пособие
предназначено для студентов вузов,  обучающихся по специальности 150202
«Оборудование и  технология сварочного производства» и нацелено на развитие
навыков устной речи и чтения литературы по специальности на  английском языке.

УДК
811

Рецензенты
              Доктор
педагогических наук, зав.кафедрой иностранных языков
         КузГТУ
Зникина Л.С.
 Доктор педагогических наук, директор
международного  информационного центра ТГПУ Федотова Е.Е.
         Кандидат    технических        наук,
 зав.кафедрой       сварочного           производства ЮТИ ТПУ Зернин Е.А.

© Юргинский технологический институт,
2007 © Оформление. Издательство ЮТИ ТПУ, 2007
CONTENTS

Введение (Preface)                                                                        4

PART 1. JOB DESCRIPTION AND WELDING EDUCATION        6
Text 1. Welding & Machine Trades                                                  7

Text 2. What is Welding and what do Welders Do                            9

Text 3. Welding Skills                                                                     12

Text 4 (Table). Welding Education and Consultation
Training Centre                                                                              16

Text 5. Taking the Plunge: A Guide to Starting
an Underwater Welding Career                                                        21

PART 2. THE HISTORY OF WELDING                                        25
Text 1. Welding History - A Story of Harnessing Heat                      26

Text 2. From the History of Welding                                                31

Text 3. Welding's Vital Part in Major
 American Historical Events                                                            35

PART 3. WELDING PROCESSES & EQUIPMENT                        40
Text 1. Introduction to Welding Processes & Equipment                   41

Text 2. Basic Principles of Welding                                                  44

Text 3. Characteristics of the Principal Welding Processes                 48

Master Chart of the Principal Welding Processes                              49

Text 4. Alternative Types of Welding                                               52

PART 4. ARC AND GAS WELDING IN DETAIL                          55
Text 1. Arc Welding                                                                       55

Text 2.Oxygas Cutting Equipment                                                   67

Text 3. Oxy-Fuel Welding and Cutting                                             80

PART 5. MODERN
DEVELOPMENTS                                                                  89

Text 1. Friction Stir Welding (FSW)                                                 90

Text 2. New Welding Method for Aluminium                                  96

Text 3. Man-machine Communication for Multi-run Arc Welding               101

Text 4 .IT in Welding and Cutting for the Welding  Engineer –
PC Programs and the Internet                                                          105

Text 5. Moving Weld Management from the Desk to the Desktop      113
PART 6. ADVANCED TECHNOLOGIES
AND THE FUTURE OF WELDING
                                                                      118

Text 1. Space-Age Welding: The Past, Present and Future
of Aerospace Join Processes                                                            119

Text 2. What Is Orbital Welding                                                      124

Text 3. Welding Forges into the Future                                             128

PART 7. HEALTH, SAFETY AND ACCIDENT
PREVENTION                                                                              137

Text 1. Health Risks of Welding Fume/Gases                                   138

Text 2. Safety and Scheduled Maintenance Protect
Your Welding Assets                                                                      143

APPENDIX 1. WELDING
THEORY & APPLICATION DEFINITIONS        147
APPENDIX 2. КЛАССИФИКАЦИЯ
ВИДОВ И СПОСОБОВ СВАРКИ      175

Введение

 Данное учебное пособие
рассчитано на подготовку по английскому языку студентов высших учебных
заведений, обучающихся по специальности 150202  «Оборудование и технология
сварочного производства». В пособие включены аутентичные тексты на английском
языке по основной сварочной тематике, снабженные упражнениями и заданиями,
направленными на развитие навыков чтения, реферирования и аннотирования с
литературы по специальности, а также навыков ведения беседы на специальные
темы.   Работа с материалом, представленным в пособии, поможет студентам не
только овладеть английской технической терминологией из области сварки и
сварочных процессов, но и  познакомиться с историей и современным состоянием
отрасли, заглянуть в будущее технологии.
 Пособие снабжено иллюстративным и
справочным материалами и может использоваться как для аудиторной, так и для
самостоятельной работы студентов.
PART
1. JOB DESCRIPTION AND WELDING EDUCATION

Lead-in

In the list below tick the places where welders are not likely to work. Add

some more places to the list

.

-   machine-building
factory workshop;
-   bridge
construction site;
-   hospital;
-   university
department;
-   shipyard;
-   bank;
-   repair shop;
-   assembly site;
- bakery.

Vocabulary

weld

сварной шов, сварка,
  сваривать(ся)

repair and maintenance

ремонт оборудования и уход
  за ним

sheet metal work

1) обработка листового металла 2) изделие из листового
  металла 3) жестяницкие работы

hobbyist

человек, увлеченный своим
  хобби

carpenter

плотник, столяр

ironworker

металлург

glazier

стекольщик

tender

1)
  лицо, присматривающее за кем-л., обслуживающее кого-л., что-л. 2) механик,
  оператор

supervisor

контролер

contractor

подрядчик, контрактор

repair shop

ремонтная мастерская

stoop

наклоняться, нагибаться

awkward

неудобный; затруднительный,
  неловкий

machine setting

1) наладка [настройка]
  станка

nondestructive testing

1) неразрушающие испытания;  2)
  неразрушающий контроль

Reading  Pre-reading

Find the Russian equivalents for the words and word
combinations in italics in the text.

Text 1. Welding & Machine Trades

Welding is a skill used by many trades: sheet
metal workers, ironworkers, diesel mechanics, boilermakers, carpenters,
marine construction, steamfitters, glaziers, repair and maintenance personnel
in applications ranging from the home hobbyist to heavy fabrication of
bridges, ships and many other projects. A variety of welding
processes are used to join units of metal. As a
welder, you may work for shipyards, manufacturers, contractors, federal,
state, county, and city governments, firms requiring maintenance mechanics,
and repair shops.

Welding, while very physically
demanding, can be very rewarding for those who enjoy working with their hands.
Welders need good eyesight, manual dexterity and hand-eye
coordination. They should also be able to concentrate for long periods of
time on very detailed work, as well as be in good enough physical shape
to bend and stoop, often holding awkward positions for long periods of
time. Welders work in a variety of environments, both indoors and out, using
heat to melt and fuse separate pieces of metal together. Training and skill
levels can vary, with a few weeks of school or on-the-job training for
the lowest level job and several years of school and experience for the more skilled
welding positions.

Skilled welders often select and set
up the welding equipment, execute the weld, and then examine the welds in order
to make sure they meet the appropriate specifications. They may also be
trained to work in a variety of materials, such as plastic, titanium or
aluminum. Those with less training perform more routine tasks, such as
the welds on jobs that have already been laid out, and are not able to work
with as many different materials.
While the need
for welders as a whole should continue to grow about as fast as average,
according the U.S. Bureau of Labor Statistics, the demand for low-skilled
welders should decrease dramatically, as many companies move towards automation.
However, this will be partially balanced out by the fact that the demand for machine
setters, operators and tenders should increase. And more skilled
welders on construction projects and equipment repair should not be
affected, as most of these jobs cannot be easily automated. Because of the
increased need for highly skilled welders, those with formal training
will have a much better chance of getting the position they desire. For those
considering to prepare themselves to a meaningful welding-career, there
are many options available.
There are also different
professional specialties and levels, that should be understood to make an
informed choice. Some of these are: welder, welding machine operator, welding
technician, welding schedule developer, welding procedure writer, testing
laboratory technician, welding non destructive testing inspector,
welding supervisor, welding instructor, welding engineer.

While-reading activity

Make a list of all the words in the text indicating:
a)   welding
professions and levels: welder, welding machine operator, …
b)  trades where welding
skill is used: …
c)   places/fields a
welder can work at (in): …
d)  personal qualities a
welder should have:

Answer the following questions on the text.
1.   What are the
trades where welding skills are used?
2.   Where can
welders work?
3.   What personal
characteristics should welders have?
4.   How does the
environment in which welders work vary?
5.   What does it
take to be s low-skilled/skilled welder?
6.   What are
welders able to do in terms of complexity of tasks and variety of materials?
7.   What are the
job opportunities for low-skilled/skilled welders for the nearest future as
specified by the U.S. Bureau of Labor Statistics?
8.   What are the
advantages of having formal training for making a welding career?
9.   As you see,
welding includes various professional specialties and levels. What is yours?

After-reading activity

Translate the following sentences from Russian into
English:

1.
Сфера применения сварки охватывает большое количество областей
промышленности.
2.
Профессия сварщика требует физической выносливости из-за частой
необходимости работы в нестационарных условиях.
3.
Для того чтобы стать квалифицированным сварщиком, необходима
длительная теоретическая подготовка и практический опыт работы.
4.
Квалифицированный сварщик должен сам уметь подбирать необходимое
сварочное оборудование, материалы и технику сварки.
5.
Чем выше квалификация сварщика, тем больше количество материалов,
с которыми он может работать, и разнообразнее виды  выполняемых работ.
6.
В настоящее время имеются большие возможности для освоения
профессии сварщика.

Look through the last paragraph of the text and say, what
exactly, in your opinion, the following welding specialists do:

welder

welding machine operator

welding technician

welding schedule developer

welding procedure writer

testing laboratory technician

welding     non    destructive inspector

testing

Writing

Write five sentences (one per each paragraph) summarizing
the main ideas of the text.

Reading

Skim the text to understand its main ideas

Text
2. What is welding and what do welders do?

Welding is the most
economical and efficient way to join metals permanently. It is the only way of
joining two or more pieces of metal to make them act as a single piece. Welding
is vital to our economy. It is often said that over 50% of the gross national
product of the U.S.A. is related to welding in one way or another. Welding
ranks high among industrial processes and involves more sciences and variables
than those involved in any other industrial process. There are many ways to
make a weld and many different kinds of welds. Some processes cause sparks and
others do not even require extra heat. Welding can be done anywhere… outdoors
or indoors, underwater and in outer space.
Nearly everything we use in our
daily life is welded or made by equipment that is welded. Welders help build
metal products from coffeepots to skyscrapers. They help build space vehicles
and millions
of other products ranging from oil drilling rigs to
automobiles. In construction, welders are virtually rebuilding the world, extending
subways, building bridges, and helping to improve the environment by building
pollution control devices. The use of welding is practically unlimited. There
is no lack of variety of the type of work that is done.
Welders are employed in many industry groups. Machinery
manufacturers
are responsible for
agricultural, construction, and mining machinery. They are also involved in
bulldozers, cranes, material handling equipment, food-processing machinery,
papermaking and printing equipment, textiles, and office machinery.
The fabricated metals products
compiles another group including manufacturers of pressure vessels, heat
exchangers, tanks, sheet metal, prefabricated metal buildings and architectural
and ornamental work. Transportation is divided into two major groups:
manufacturers of transportation equipment except motor vehicles; and motor
vehicles and equipment. The first includes shipbuilding, aircraft, spacecraft,
and railroads. The second includes automobiles, trucks, buses, trailers, and
associated equipment.
A small group of welders
belongs to the group of repair services. This includes maintenance and repair
on automobiles or refers to the welding performed on industrial and electrical
machinery to repair worn parts. The mining, oil extraction, and gas extraction
industries form yet another group. A large portion of the work
involves drilling and extracting oil and gas or mining of
ores, stone, sand and gravel.
Welders are also employed in the primary
metals industries to include steel mills, iron and steel foundries, smelting
and refining plants. Much of this work is maintenance and repair of facilities
and equipment. Another group is the electrical and electronic equipment
companies. Welding done by this group runs from work on electric generators,
battery chargers, to household appliances.
Public administration
employs welders to perform maintenance welding that is done on utilities,
bridges, government armories and bases, etc. Yet another group involves
wholesale and retail establishments. These would include auto and agricultural
equipment dealerships, metal service centers, and scrap yards.
Probably the smallest group of
welders, but perhaps those with the biggest impact on the public are the artist
and sculptors. The St. Louis Arch is possibly one of the best known. But there
are many other fountains and sculptures in cities and neighborhoods around the
world.

While-reading activity

Find
the English equivalents for the following words and word combinations: валовой
национальный продукт, на открытом воздухе, в помещении, космический корабль,
горное оборудование.

True or false?

1.   Welding is an
important process employed by modern industry.
2.   All welding
processes are similar.
3.   All welding
processes require work pieces to be heated.
4.   The smallest
group of welders belongs to the group of repair services.
5.   Welding is the
only way to join metals.

After-reading activity

Make up a summary of the text using the following
sentences as a beginning:]

1. Welding is…. 2. Welding ranks…
3. There are many kinds… 4. Welding can be made… 5. Welders can… 6. The use of
welding is… 7. Welders are employed in … .

Lead-in

You already know where welders are involved. Read the text
below and find out if there are more such places.

Vocabulary

journeyman (person)

наемный квалифицированный
  рабочий

apprentice

ученик

plate working

обработка листового металла

blueprint

1) делать светокопию,
  копировать чертеж 2) делать разметку

brazing

пайка твердым припоем (из
  меди и цинка)

GTA (gas tungsten arc)
  welding

сварка неплавящимся
  электродом

TIG (ungsten inert gas
  welding)

дуговая сварка вольфрамовым
  электродом в среде инертного газа

SMAW (shielded metal arc welding)

дуговая сварка покрытым
  металлическим электродом

SAW (submerged arc welding)

(дуговая) сварка под флюсом

resistance welding

(контактная) сварка
  сопротивлением

flux core

флюсовая сердцевина (
  порошковой проволоки )

metal core

металлический сердечник

shift work

(по)сменная работа, работа
  по сменам

Reading

Text 3. Welding
Skills
A Welder permanently joins pieces of metal with metal
filler, using heat and/or pressure. Welders join parts being manufactured, they
build structures and repair broken or cracked parts, according to
specifications.
Job Related Skills, Interests and Values

•
using and maintaining tools, material handling equipment and
welding equipment;
•
reading and interpreting blueprints;
•
acquiring thorough knowledge of arc, gas and resistance
welding theory ;
•
laying out, cutting and forming metals to specifications;
•
preparing the work site;
•
fitting sub-assemblies and assemblies together and preparing
assemblies for welding ;
•
welding using shielded metal arc welding, gas metal arc
welding, gas tungsten arc welding, flux core or metal core arc welding,
submerged arc welding and plasma arc welding processes;
•
carrying out special processes such as welding studs and
brazing;
•       ensuring
quality of product/process before, during and after welding;  What
Preparation and Training Do You Need?
To become a Welder you should
complete Grade 12 with credits in mathematics (particularly technical math) and
some shop courses. In Ontario, welding is an unrestricted trade; completion of
an apprenticeship could take approximately 3 years including 3 periods of 8
weeks (720 hours) in-school theory. Upon successful completion of the training
agreement, you will receive a Certificate of Apprenticeship.
What’s
Your Future as a Welder?
Most workers in this occupation
work full-time, sometimes in shift work, usually indoors. Those with the
ability to work with high-technology welding applications may have better
employment opportunities. The bulk of employment opportunities are predicted to
occur in the non-electrical, machinery, construction and metal-fabricating
industries. Some workers will become self-employed. Examples of companies that
employ welders include:
•
Fabricating shops;
•
Manufacturers of structural steel and platework;
•
Construction industries;
•
Boilers;
•
Heavy machinery contractors;
•
Aircraft contractors;
•
Ship building and other transportation contractors;
•
Specialized welding shops.
Wage Rate
•       as
an apprentice you would start at a wage rate less than that of a journeyperson

•       this
rate increases gradually as you gain competency
•
the wage range for fully qualified welders according to the Peel
Halton Dufferin HRDC Wage Book is between $9.50/hr to $16.18/hr, with a median
salary of $12.50/hr.
After reading activity
Revise the information of Unit1 and make a list of the
things welders should be able to do and places they can work at.
Self-Rating
Ask Yourself: Is Working as a Welder For You?

Are you good at preparing and planning a
  job from start to finish?

 Yes

No

Can
  you look at a diagram or shop drawing and visualize how things come together?

 Yes

No

Do you like figuring out what’s wrong with
  something and then repairing it?

 Yes

No

Are you able to bend, stretch, kneel, stand
  for long periods and lift material and supplies?

 Yes

No

Would it bother you to work around
  dangerous gases and intense heat?

 Yes

No

Do you have good hand/eye coordination to
  guide a welding arc along the edges of metal?

 Yes

No

If
you answered Yes to most of these questions, welder may be for you!
Lead-in

You already know what sort of skills you should have to be
a welder. Now think of the answers to the following questions:

1.   How long should
a person be trained to become a skilled welder?
2.   Do you think
that a welder should be able to use all kinds of welding?
3.   What is more
interesting to you personally: welding techniques, welding inspection (other)?

Vocabulary

technique

1) техника, способ,
  технические приемы 2) метод; методика,

case study

учебный пример; разбор
  конкретного случая

shielded metal arc welding

дуговая сварка покрытым
  металлическим электродом

arc welding

электродуговая сварка

submerged arc welding

дуговая сварка под флюсом

oxyfuel

газоплазменный

electric resistance
  welding

(контактная) сварка
  сопротивлением

tensile test

испытание на растяжение

bending test

испытание на изгиб

impact test

испытание на ударную
  вязкость

discontinuity

отсутствие непрерывности,
  нарушение последовательности; несплошность

volumetric

объемный

hardness

твердость, прочность;
  сопротивляемость (механическим воздействиям)

tension

натяжение; растяжение, растягивание, удлинение

site welding

монтажные сварочные работы

heat flow

тепловой поток

heat treatment

термическая обработка

welding metallurgy

металлургия сварки

hardenability

1) закаливаемость 2)
  прокаливаемость 3) способность к закаливанию

weldability

свариваемость

non-ferrous

цветной (о металле), не
  содержащий железа

filler metal

присадочный металл

alloy

сплав

ASME

сокр. от American Society
  of Mechanical Engineers Американское общество инженеров-механиков

AWS

сокр. от American Welding
  Society Американское сварочное общество

Match the words from the list below with their definitions

a) alloy, b) joint, c) inspection, d) welding, e) laser, f)
design, g) property, h) course, j) plasma, k) arc.

1.   To contrive, to
formulate, to project, to draw, to plan, to sketch out;
2.   Joining pieces
of metal (or nonmetal) at faces rendered plastic or liquid by heat or pressure
(or both).
3.   a) A junction
or mode of joining parts together; b) the place where two things are joined
together
4.   The luminous
arc or bridge across a gap between two electrodes when an electric current is
sent through them.
5.   a) A careful,
narrow or critical examination or survey; b) an official examination.
6.   An instrument
which amplifies light waves by stimulation to produce a powerful, coherent beam
of monochromatic light, an optical maser.
7.   Metal blended with
some other metallic or nonmetallic substance to give it special qualities, such
as resistance to corrosion, greater hardness, or tensile strength.
8.   A planned
programme of study.
9.   Peculiar or
inherent quality.
10.
A hot, ionized gas containing approximately equal numbers of
positive ions and electrons.

Reading and Speaking

Imagine you are a trying to choose a welding course to
your needs. Which one will you choose if your needs are like these:

1.   You have to
know how to carry out mechanical tests.
2.   You are
interested in welding ferrous alloys and non ferrous alloys.
3.   You want to
introduce computers in your welding process.
4.   You are new to
welding and would like to be introduced to basic welding processes.
5.   You want to
learn how to choose the right type of welding for your specific purposes.
6.   You want to be
a highly qualified and certified expert in the field of welding.
7.   You want to be
familiar with welding standards

Use the table below to choose the course.

Text 5 (Table).
Welding Education and Consultation Training Centre

Course

Course Objectives

Course Outlines

Welding

The main objective of this

Materials properties related to

Design

course is to introduce
  welding engineers to the subject of welding design.

welding. Welding process selection. Types
  of welded joints. Welding Accessibility

Many factors have to be
  considered in this issue. These factors include: consumer requirement,
  technical specifications, and
environmental and
  economical constrains

and Inspection. Economical Analysis. Design
  information. Welding symbols. Case studies.

Welding
Fundamentals

The main objective of this
  course is to familiarize engineers and inspectors to various aspects related
  to welding techniques, inspection and quality procedures in welding
  industry. The course is designed for engineers of scientists with no or
  little experience in the welding field.

Welding processes: Shielded metal Arc
  welding, Arc welding, Gas tungsten Arc welding, Submerged Arc
  welding & Oxyfuel welding & electric resistance.
  Cutting processes: Oxygen cutting, plasma cutting and laser cutting.
  Inspection of weldments: Nondestructive testing of welments. Mechanical
  testing of weldments (tensile, bending, impact).

Welding Inspection

The course discusses both
  qualification inspections and on-line inspections of welded joints. These
  include mechanical tests (tension, bending, impact, ...etc, and non
  destructive tests.

Significance of weld discontinuities.
  Welding inspection (non-destrutive testing techniques: surface inspection,
  magnetic particle, volumetric, radiography, and ultrasonic).
  Destructive testing techniques: hardness, tension, bending,
  ...etc. The control of quality during shop operations. The control of quality
  during site welding.

Non
Destructive testing
Certification:

Level I: Is to train
  inspectors to be able to pass level I examination and to be able to inspect
  using the chosen

Physical principals of test. Processing.
  Test equipment and materials. Codes, standards, procedures and

Magnetic
Particle &
Liquid
Penetrant
Testing (MT
& PT)

technique. Level II: Is to
  upgrade level I inspectors to be able to pass level II examination and to be
  able to inspect, write a report, etc in the chosen technique.

safety. Test physical principals. Equipment
  and radiation source. Radiographic recording. Work parameters and conditions.
  Defectology. Selection of techniques. Test methods according to standards.
  Personal safety and protection.

Welding Metallurgy

The course delineates the
  main changes in the microstructure and/or the morphology of the metals and
  alloys during welding that lead to changes in properties. Alloys discussed in
  the course include all types of steels, Cast Iron, Nickel, Copper alloys,
  ...etc

Heat flow in welding. Effect of
  pre-and-post weld heat treatment. Introduction to welding
  metallurgy (hardenability and weldability). Metallurgy of
  steels. Welding of ferrous alloys: Carbon-steels, Low alloy steels, Stainless
  steels, and Cast Iron. Welding of non ferrous alloys: Al- Ni-
  and Cu-alloys. Identification and specifications of welding filler metals.
  Case studies.

Welding
Quality
Assurance

For each application, the
  welding process is controlled by specific code or standard. The course
  includes discussions of ASME boiler and pressure vessel code AWS
  steel structure code and other standards.

Welding co-ordination: tasks &
  responsibility. Quality requirements for welding. Qualification of welding
  procedures and welders. International codes and standards. Mechanical testing
  of welds. Non-destructive testing of welds. Documents for weld quality
  assurance.
Case studies.

Welding
Techniques

Selection of the welding
  process is very important. The course discusses the variables of each welding
  process and gives directions for selecting the proper

Overview of welding techniques and
  processes. Conventional techniques: arc, Oxy fuel and resistance welding.
  Non-conventional: plasma, electron beam, laser

process for specific application. Welding processes
  discussed include:
SMAW, GMAW, GTAW, etc.

welding. Flame and arc cutting of metals.
  Computer applications in welding. Case studies.

AWS
Certified welding Engineer

The highest level of
  certification in the field of
welding

To get certified as a welding engineer you need to attend
  four exams: Fundamentals of science. Applied science.
Fundamentals of welding.
Applied welding.

Translate the following sentences into Russian:

1.
Кислородная, плазменная и газовая резка изучаются в курсе «Основы
сварочного производства».
2.
Методика проведения разрушающих испытаний изучается в курсе
«контролер сварочного участка» («приемщик сварочных изделий»).
3.
К традиционным типам сварки относятся: электродуговая,
кислородно-газовая и контактная электросварка.
4.
Каждый сварщик должен знать правила личной безопасности и
использовать индивидуальные средства (equipment) защиты, а также разбираться в
международных кодах и стандартах.
5.
Во время сварки происходит изменение микроструктуры металла, что
приводит к изменению его свойств.
6.
При проведении монтажных сварочных работ особенно важно
контролировать качество шва.

Writing

Write a short summary about a welder’s competence. Cover
the following areas:
-   welding
courses welders can take;
-   types of
welding welders should be able to use,  - testing techniques welders should
know about.

Lead-in

Before you read, think of the following questions:
1.   What does it
mean to be a surface welder?
2.   When does it
become necessary to weld underwater?
3.   Do you consider
underwater welding an interesting career opportunity?

Vocabulary

plunge

прыжок, ныряние, погружение
  (в воду или другую среду)

take the plunge

сделать решительный шаг

commercial

1)
  коммерческий, торговый; 2) промышленный 3) рентабельный, прибыльный Syn:
  profitable 4) технический

subsea

погруженный в воду,
  подводный

rigging

1)
  оснастка, 2) сборка, регулировка, установка, монтаж (конструкций,
  оборудования и т.д.) 3) оборудование, оснащение, снаряжение

fitter

сборщик, слесарь-сборщик

alignment

выверка, выравнивание,
  регулировка

beveling

разделка кромок

stripping

сдирание, обдирание;
  зачистка; снятие верхнего слоя

patch

заплата

scuba diver

лёгкий водолаз, аквалангист

physical (examination)

врачебный/медицинский
  осмотр

oxyfuel

горючая смесь газов

draft

делать чертеж,
  проектировать

lapse

юр. прекращение,
  недействительность права (на что-л.)

While-reading
activity

Think of the answers to the following questions:

1.   How can you
communicate to your company?
2.   What can be
a source of helpful information for a welder?
3.   Who can be
called a certified welder?
4.   How do people
apply for employment?
5.   What
professions are physical demanding?
6.   What kind of career
goals may a welder have?
7.   What is
formal training?

Give the Russian equivalents for the word combinations in
italics in the text.

Reading

Text 5. Taking the
Plunge: A Guide to Starting an Underwater Welding Career

Over the years, a
number of people have expressed an interest in careers in underwater welding,
but were unsure how to get started. Welders, students, divers, and other
interested men and women have contacted the American Welding Society (AWS) for
guidance. In order to help those prospective underwater welder-divers, the D3B Subcommittee
on Underwater Welding has provided answers for some commonly asked
questions.
1.
What skills are prerequisite to entering the field of
underwater welding?
The skills suggested for entering
the field of underwater welding can best be defined by the following typical
description of a welder-diver from the AWS D3.6 Standard. "Welder-diver: A
certified welder who is also a commercial diver, capable of
performing tasks associated with commercial subsea work, weld setup and
preparation, and who has the ability to weld in accordance with the AWS
D3.6." By description, an experienced welderdiver must possess: commercial
diving skills (i.e., be familiar with the use of specialized commercial
diving equipment, have an understanding of diving physiology, diving safety, rigging,
the underwater environment, communication, etc.); weld setup and preparation
skills (i.e., the ability to perform tasks typically assigned to a fitter
or rigger, such as materials alignment and materials preparation
including beveling, stripping of concrete, fitting a steel patch
or repair plate, etc.,); and the ability to certify to a required underwater
weld procedure.
2.
I am a certified surface welder, what other training do I
need to qualify as a welder-diver?
The majority of
work performed by an average welder-diver does not involve the welding
operation itself, but rather executing the tasks that lead up to and follow the
actual welding activities. Except under special circumstances, a
welder-diver in most cases must posses both certified welder skills and
commercial diving skills. It is suggested that if you have no prior commercial
diving experience you should attend one of the recognized commercial diving
schools. The candidate may be required to pass a diving physical prior to school
acceptance and in some cases a written exam. It is suggested that a dive
physical be taken regardless, to avoid going through the expense of training
only to later find you have a disability that prevents your entering the
profession. Once that basic commercial diver training is completed, it is
common practice to apply for employment at one of many commercial diving
companies that offer underwater welding as a service. An interview with the
company of your choice is recommended to express your career goals in underwater
welding and past welding experience. Expect to begin your career as a diver
tender (apprentice diver) initially. As a diver tender you will gain
valuable practical experience while learning the trade.
3.
I am already a certified diver, what other training do I
need to qualify as a welder-diver?
The welding processes, classes of
weld and qualification tests associated with underwater welding are described
in ANSI/AWS D3.6. We recommend the specification as a reference for weld
procedure and welder qualification. It is also a good source of other
helpful information. If you are already certified as a "commercial
diver" and work for a company that offers underwater welding services, it
is recommended that you communicate to your company your career objectives
and ask what welder skills they are looking for. If you are certified as a
"scuba diver", it is suggested that you attend a commercial
diving school. Sport dive training does not include the safe use of commercial
diving equipment, offshore commercial work environment/safety, and other
education. Underwater welding is a skill you also have to master once you
obtain the basic commercial diving skills required.
4.
What are the age limitations of a welder-diver?
There is no age restriction on
commercial welder-divers. There are, however, physical requirements. It is
recommended and generally required that all commercial divers pass an annual
dive physical. The commercial diving profession is physical demanding.
It is rare to see an active commercial welder-diver over the age of 50.
5.
What salary can I expect to make as a welder-diver?
We know some
welder-divers earn $15,000 per year while others earn in excess of $100,000.
Because the majority of welder-divers are paid on a project-by-project basis,
salaries are subject to the same variables as work availability. In addition,
other factors such as depth, dive method and diving environment affect pay
rates. The company with whom you gain employment should be able to tell you the
salary range you can expect to earn.
6.
What other skills are recommended to supplement my
qualifications as a welder-diver?
Ideally, a diving contractor would like
its welder-divers to be "a jack of all trades and a master of them
all!" Practically speaking, possessing the skills that are common to
underwater welding operations, in addition to welding and diving, are
recommended. Primarily these skills are: underwater cutting (oxyfuel,
abrasive water jet, mechanical cutting equipment, etc.); fitting and rigging;
inspection and nondestructive testing (visual, magnetic particle, ultrasonics,
radiography, eddy current, etc.); drafting; and underwater photography (still
photo and video). The more skills the welderdiver maintains the more valuable
he becomes in meeting project qualification requirements. The most desirable
underwater welder-divers are those who are qualified to: assist the diving
contractor in pre-job planning (e.g., having the ability to photograph/video, draft
and report on work requirements prior to the actual underwater welding
operation); cut, clean, rig, install, and fit up the sections they will weld;
and work with personnel responsible for inspecting the completed welds. Formal
training is recommended for whatever skills you wish to qualify for.
Maintaining the qualifications you obtain is just as important as receiving
them as there has been many a job lost to a welder-diver who has let his
certification lapse.
7.
What future career opportunities are there for an
experienced welder-diver?
There are a number of career
opportunities for experienced welderdivers. Many go on to become engineers,
instructors, and diving operations supervisors, fill management positions,
qualify as AWS Certified Welding Inspectors (CWI), and serve as consultants for
underwater welding operations and other related fields. Ideally, a career as a
welder-diver should serve as a stepping stone to other opportunities for
those who choose the profession. Industry has and will continue to demand
higher quality standards for underwater welds and more certification of
underwater welding systems and personnel.

After-reading activity

Continue filling in the following table:

Operations
  both surface welder-divers do

and

Operations only welder-divers do

weld setup and preparation, …

underwater cutting, …

Speaking

Correct the following statements to make them correspond
to the text:

1.   Welder-divers
must have the skills of commercial diving but need not be certified.
2.   The majority of
work performed by an average welder-diver includes only welding operation
itself.
3.   Welder-divers
apply for employment at commercial diving companies before their diver training
is completed.
4.   Commercial
welder-diver is the same as scuba diver.
5.   You cannot be a
welder-diver if you are over 50 years old.
6.   To possess
commercial diving skills means to be able to do underwater weld procedures.
7.   Welder-divers
earn from $15,000 to $100,000 per year depending on their work experience.
8.   To pass a physical
examination for welder diver you need to go through formal training.
9.   Past welding
experience doesn’t count if you choose to be a welder-diver.

Answer the following questions:

1.   Who can be a
welder-diver?
2.   What sorts of
basic and supplementary skills must a welder-diver possess?
3.   How can
certified surface welders become welder-divers?
4.   What is more
important: receiving the welder-diver qualifications or maintaining them?
5.   Why do
commercial divers pass an annual dive physical?
6.   Do
welder-divers have any future career opportunities?
7.   Do you think
surface welding equipment can be used underwater?

Translate the following sentences into Russian:

1.
Большое количество людей проявляет интерес к профессии подводного
сварщика.
2.
Сварщик-подводник – это квалифицированный сварщик, обладающий
всеми навыками, необходимыми для сварки на поверхности и под водой.
3.
Перед зачислением в школу сварщиков-подводников кандидаты
проходят обязательное медицинское освидетельствование.
4.
Полезными навыками сварщиков-подводников являются: фото- и
видеосъемка, создание чертежа, установка оснастки и др.
5.
Для многих профессиональных сварщиков навыки подводной сварки
становятся залогом дальнейшего карьерного роста.

Think and say

1.
The word combination taking the plunge is a set phrase
(связанное фразеологическое сочетание). Is it a good title for this text? Why?
2.
Another set phrase in the text is a stepping stone. What
are possible stepping stones in your welding career?

PART
2. THE HISTORY OF WELDING

Lead-in

Think of the answers for the following questions:
1.   Why did welding
become necessary?
2.   Is welding a
new profession? 3 Who were the first welders?
4. Who invented modern welding?

Vocabulary

forge

выковывать, ковать

oxyacetylene

1) автогенный 2) кислородно-ацетиленовый

welding rod

сварочный пруток

MIG

metal
  inert gas welding сварка металлическим электродом в инертном газе

TIG

tungsten
  inert gas welding дуговая сварка вольфрамовым электродом в среде инертного
  газа

torch

горелка

submerged welding

arc (дуговая) сварка под
  флюсом

molten pool/puddle     сварочная
  ванна; ванна жидкого металла

Reading

Text 1. Welding History
- A Story of Harnessing Heat

Joining metal and
welding history go back several millennia starting in the Bronze Age then Iron
Age in Europe then the Middle East. Welding was used in the Iron pillar in
Delhi, India, about 310 AD, weighing 5.4 metric tons (picture at left). The
Middle Ages brought forge welding, blacksmiths pounded hot metal until it
bonded. In 1540, Vannoccio Biringuccio released De la pirotechnia, which
includes descriptions of the forging operation. Renaissance craftsmen gained
skilled in the process, and the welding continued to grow during the following
centuries.
Welding was transformed during the
19th century. In 1800, Sir Humphrey Davy invented the electric arc, and
advances in welding continued with the metal electrode by a Russian, Nikolai
Slavyanov, and an American, C.L. Coffin late in the 1800s.
Acetylene was discovered in 1836 by
Edmund Davy, but was not practical in welding until about 1900, when a suitable
blowtorch was developed. At first, oxyfuel welding was the more popular welding
method due to its portability and relatively low cost. As the 20th century
progressed, it fell out of favor for industrial applications. It was largely
replaced with arc welding, as metal coverings (known as flux) for the electrode
that stabilize the arc and shield the base material from impurities continued
to be developed.
In 1881 a Russian
inventor, Benardos demonstrated the carbon electrode welding process. An arc
was formed between a moderately consumable carbon electrode and the work. A rod
was added to provide needed extra metal.
Thermite welding was invented in
1893, another process, oxyfuel welding, became well established.
Around 1900, A. P. Strohmenger
brought a coated metal electrode in Britain, which had a more stable arc, and
in 1919, alternating current welding was invented by C.J. Holslag, but did not
become popular for another decade.
Resistance welding was developed
during the end of the 19th century, with the first patents going to Elihu
Thompson in 1885, and he produced advances over the next 15 years.
In 1904 Oscar Kjellberg in Sweden,
who started ESAB, invented and patented the covered electrode. This electric welding
process made strong welds of excellent quality.
World War I caused a major surge in
the use of welding processes, with the various military powers attempting to
determine which of the several new welding processes would be best.  The
British primarily used arc welding, even constructing a ship, the Fulagar, with
an entirely welded hull. The Americans were more hesitant, but began to
recognize the benefits of arc welding when the process allowed them to repair
their ships quickly after a German attack in the New York Harbor at the
beginning of the war. Arc welding was first applied to aircraft during the war
as well, as some German airplane fuselages were constructed using the process.
During the 1920s, major advances
were made in welding technology, including the introduction of automatic
welding in 1920, in which electrode wire was fed continuously.
Shielding gas became a subject
receiving much attention, as scientists attempted to protect welds from the
effects of oxygen and nitrogen in the atmosphere. Porosity and brittleness were
the primary problems, and the solutions that developed included the use of
hydrogen, argon, and helium as welding atmospheres.
During the
following decade, further advances allowed for the welding of reactive metals like
aluminum and magnesium.  This, in conjunction with developments in automatic
welding, alternating current, and fluxes fed a major expansion of arc welding
during the 1930s and then during World War
II.

A significant
invention was defined in a patent by Alexander, filed in December 1924, and
became known as the Atomic Hydrogen Welding Process. It looks like MIG welding
but hydrogen is used as the shielding gas which also provides
extra heat.A major innovation was described in a
patent that defines the Submerged Arc Process by Jones, Kennedy and Rothermund.
This patent was filed in October 1935 and assigned to Union Carbide
Corporation. The following was excepted from an article written by Bob Irving
in he Welding Journal: “The importance of welding was emphasized early in the
war when President Roosevelt sent a letter to Prime Minister Winston Churchill,
who is said to have read it aloud to the members of Britain's House of Commons.
The letter read in part, "Here there had been developed a welding technique
(referring to Submerged Arc Welding) which enables us to construct
standard merchant ships with a speed unequalled in the history of merchant
shipping."
Russell Meredith working at Northrop
Aircraft Company in 1939-1941 invented the TIG process. This new process was
called "Heliarc" as it used an electric arc to melt the base material
and helium to shield the molten puddle. Mr.Jack Northrop's dream was to
build a magnesium airframe for a lighter, faster warplanes and his welding
group invented the process and developed the first TIG torches. The patents
were sold to Linde who developed a number of torches for different
applications. They also developed procedures for using Argon which was more
available and less expensive than Helium.
In 1957, the flux-cored arc welding
process debuted, in which the selfshielded wire electrode could be used with
automatic equipment, resulting in greatly increased welding speeds, and that
same year, plasma arc welding was invented. Electroslag welding was released in
1958, and it was followed by its cousin, electrogas welding, in 1961.
Other recent
developments in welding include the 1958 breakthrough of electron beam welding,
making deep and narrow welding possible through the concentrated heat source.
Following the invention of the laser in 1960, laser beam welding debuted
several decades later, and has proved to be especially useful in high-speed,
automated welding.
Both of these processes, however, continue to be quite
expensive due the high cost of the necessary equipment, and this has limited
their applications.

After-reading activity

Find equivalents for the following words combinations in
the text:

Угольный электрод, электрод с покрытием, защитный газ,
торговое судоходство, открытая печь, военный самолет, открытый горн, источник
тепла, признавать преимущества электродуговой сварки, высокая стоимость.

Match the dates, names and inventions from the following
table:

1540

Vannoccio Biringuccio

discovered acetylene

1800

Sir Humphrey Davy

invented the electric arc

1800s.

Nikolai Slavyanov, C.L.
  Coffin

developed metal

electrode

1836

Edmund Davy

brought a coated metal
  electrode

1881

A. P. Strohmenger

invented and patented the
  covered electrode

1900

Benardos

described forging operation

1904

C.J. Holslag

invented alternating
  current

1919

Oscar Kjellberg

demonstrated the welding
  process with carbon electrode

1935

Jones, Kennedy and Rothermund

developed Submerged Arc
  Welding

1924

Alexander

patented Atomic Hydrogen
  Welding process

After-reading discussion

True or false?

1.   Arc welding was
used to build the Iron pillar in Delhi, India.
2.   The discovery
of acetylene made it possible to achieve higher heating temperatures.
3.   The first
electrode used in welding was a covered one.
4.   The British
Prime Minister Winston Churchill was a famous welder.
5.   Oxygen is used
as shielding gas in TIG welding.
6.   The TIG process
made it possible to construct planes faster.

Answer the following question on the text:

1.   Which process
was developed earlier, MIG or TIG?
2.   Why is rod
added in carbon electrode welding?
3.   What is the
difference between the Atomic Hydrogen Welding process and the MIG process?
4.   What kind of
gas was first used to shield the molten puddle?
5.   Is tungsten
electrode consumable?

Speaking

Translate the following sentences from Russian into
English:

1.
Ковка – первый в истории метод соединения металлов, при котором
было необходимо нагреть соединяемые металлы до высокой температуры на открытом
пламени.
2.
Открытие ацетилена и соединение его с кислородом позволило
значительно повысить температуру нагрева свариваемых металлов.
3.
Российский изобретатель Бенардос впервые использовал неплавящийся
угольный электрод.
4.
Использование электрода с покрытием значительно повысило качество
получаемых сварных соединений.
5.
Изобретение дуговой сварки под флюсом позволило ускорить
строительство торговых судов.
6.
При дуговой сварке вольфрамовым электродом в качестве инертного
газа использовался гелий, который позднее был заменен более дешевым в получении
аргоном.

Vocabulary

joining, joint

соединение,         связь,          сращивание,
  шов

armour

броня

carburization

науглероживание

brittle

хрупкий, ломкий

interlayering

чередование слоев

high-carbon

высокоуглеродистый

hammer forging

свободная ковка на молоте

cast iron

чугун

blacksmith

кузнец

jeweler

ювелир

fusion

плавка; расплавление

riveting

производить клёпку — rivet,
  join by rivets

boiler

паровой котёл, бойлер

oxyacetylene

ацетилено-кислородный

consumable

расходуемый

bare

непокрытый

coating

покрытие

spot

точечная

seam

роликовая

sheet

лист

butt

стыковая

tungsten

вольфрам

beam

луч

bonding

соединение, (с)крепление,
  связывание

Skim the text to find out more facts about the history of
welding.
Find the English equivalents in the text for the following
word combinations:

Сварочная
технология, твердое железо, кухонная утварь, листовая сталь, сложное покрытие,
алюминиевая проволока, сложное покрытие, острая необходимость, проволока без
покрытия.

Reading

Text 2. From the History
of Welding

Welding is a
technique used for joining metallic parts usually through the
application of heat. This technique was discovered during efforts to manipulate
iron into useful shapes. Welded blades were developed in the first millennium
AD, the most famous being those produced by Arab armourers at Damascus,
Syria. The process of carburization of iron to produce hard steel was
known at this time, but the resultant steel was very brittle. The
welding technique - which involved interlayering relatively soft and
tough iron with high-carbon material, followed by hammer forging - produced
a strong, tough blade.
In modern times the improvement in
iron-making techniques, especially the introduction of cast iron, restricted
welding to the blacksmith and the jeweler. Other joining
techniques, such as fastening by bolts or rivets, were widely applied to new
products, from bridges and railway engines to kitchen utensils.
Modern fusion welding
processes are an outgrowth of the need to obtain a continuous joint on
large steel plates. Rivetting had been shown to have disadvantages,
especially for an enclosed container such as a boiler. Gas welding, arc
welding, and resistance welding all appeared at the end of the 19th century.
The first real attempt to adopt welding processes on a wide scale was made
during World War I. By 1916 the oxyacetylene process was well developed,
and the welding techniques employed then are still used. The main improvements
since then have been in equipment and safety. Arc welding, using a consumable
electrode, was also introduced in this period, but the bare wires initially
used produced brittle welds. A solution was found by wrapping the bare
wire with asbestos and an entwined aluminum wire. The modern electrode,
introduced in 1907, consists of a bare wire with a complex coating of
minerals and metals. Arc welding was not universally used until World War II,
when the urgent need for rapid means of construction for shipping, power
plants, transportation, and structures spurred the necessary development work.
Resistance welding, invented in 1877
by Elihu Thomson, was accepted long before arc welding for spot and seam
joining of sheet. Butt welding for chain making and joining bars
and rods was developed during the 1920s. In the 1940s the tungsten-inert
gas process, using a nonconsumable tungsten electrode to perform fusion
welds, was introduced. In 1948 a new gasshielded process utilized a wire
electrode that was consumed in the weld. More recently, electron-beam
welding, laser welding, and several solidphase processes such as diffusion bonding,
friction welding, and ultrasonic joining have been developed.

After-reading activity

Refer the following statements to each of the passages of
the text:

1.   Application of
welding techniques is decreasing nowadays.
2.   Welding
originated from the attempts to shape metal into useful forms.
3.   Resistance
welding is one of the earliest types of joining metals.
4.   Industrial
development in the 1950-s expedited (ускорять) the advance of welding
technologies.

Speaking

True or false?

1.   Only heat is
used for joining metallic parts in welding.
2.   The process of
carburization of iron is rather new.
3.   The blacksmith
and the jeweler continue to use welding techniques in their work.
4.   Welding is the
only technique of joining metallic parts.
5.   The modern
electrode consists of a bare wire with asbestos.
6.   Arc welding was
not used after World War II.
7.   Diffusion bonding
and friction welding are solid-phase processes.
8.   Rivetting is
now widely used for producing an enclosed container such as a boiler.

Answer the following questions:

1.   What is
welding?
2.   How was welding
discovered?
3.   Who were the
first welders?
4.   What did the
first welding technique for making blades involve?
5.   Did the
improvement in iron-making techniques conduce to the development of welding?
6.   Is it efficient
to apply riveting for making boilers?
7.   When did gas,
arc and resistance welding appear?
8.   What was the
quality of the welds produced by the arc welding using bare wires like?
9.   What does the
coating of the modern electrode consist of?
10.
What are the years 1877, 1916, and 1948 remarkable for in terms
of welding?

Translate from Russian into English:

1.
Арабских оружейников, изготавливавших кованые клинки, можно
считать первыми сварщиками.
2.
Появление  методов      сварки        плавлением          было  обусловлено
необходимостью производства изделий из крупнолистовой стали.
3.
Впервые сварка стала использоваться в массовом производстве во
время первой мировой войны.
4.
Вторая мировая война ускорила внедрение электродуговой сварки. 5.
Современный сварочный электрод имеет сложное покрытие, состоящее из композитных
материалов.
6. Помимо сварки, клепка и болтовые соединения являются
основными методами соединения металлов.

Writing

Write a short report on the history of welding mentioning:

Dates: first millennium AD, 1540, 1800, 1836,
1881, , 1877, 1881, 1892, 1900, 1904, 1907, 1924, 1935, 1948.
Names: Alexander, Jones, Kennedy and
Rothermund, Morehead and Wilson, Oscar Kjellberg, Benardos, Russell Meredith,
Edmund Davy, Nikolai Slavyanov, C.L. Coffin, Vannoccio Biringuccio, Sir
Humphrey Davy.
Places: Syria, Russia, Sweden, the US, Britain;

Inventions: modern electrode, resistance
welding, oxyacetylene process, MIG, TIG, atomic hydrogen welding process,
submerged arc welding, carbon electrode.

Lead-in

Think of the answers for the following questions:

1.   How can welding
influence the history of a country?
2.   In what fields
of industry, in your opinion, is welding especially important?
3.   What modern
machines and structures cannot be produced without welding processes?
4.   What welding process,
arc or gas ones, has played a more important part in developing      new   technologies?
       What  particular     aspect(s)     of      this process/processes is/are
of  significance for industry development?

Vocabulary

war effort

военная экономика

rivetting

клепка

brittle fracture

хрупкий излом

notch

зубец; вырез, паз, пропил,
  прорез

crack propagation

развитие трещин

fusion welding

сварка плавлением

field welding

сварка в полевых условиях, сварка при монтаже

toughness

твердость

planeload

полная загрузка самолета

X-ray inspection

рентгенодефектоскопия

induction heating

индукционный нагрев

structural steel

конструкционная сталь

rolled steel

стальной прокат

fillet weld

угловой сварной шов

contact face

поверхность контакта

electroslag welding

электрошлаковая сварка

Pre-reading activity

Find the following figures in the text and say what they
relate to:

140, 20, 5171, 2200, 1945, 525, 531, 2710, 250,000,
58, 117, 1915, 1931, 1977, 120, 176,000, 500,000, 586,000, 17,000, 80, 373,500,
52.

Model: 2200 - 2200 passengers were
killed on the Mississippi River when the steamboat Sultana blew up.

Reading  Text 3. Welding's Vital Part  in Major
American Historical Events

Shipbuilding The  finest  hours  for     U.S.
shipbuilding were during World War II when 2710 Liberty ships, 531 Victory
ships and 525 T-2 tankers were built for the war effort. Through 1945,
some 5171 vessels of all types were constructed
to American Bureau of Shipping (ABS) class during the
Maritime Commission wartime shipbuilding program. At this time in shipbuilding
history, welding was replacing riveting as the main method of assembly.
The importance of welding was
emphasized early in the war when President Roosevelt sent a letter to Prime
Minister Winston Churchill, who is said to have read it aloud to the members of
Britain's House of Commons. The letter read in part, "Here there had been
developed a welding technique which enables us to construct standard merchant
ships with a speed unequaled in the history of merchant shipping."
The technique
the President was referring to was undoubtedly submerged arc welding, which was
capable of joining steel plate as much as 20 times faster than any other
welding process at that time.
During this
period of assimilation, eight Liberty ships were lost due to a problem called brittle
fracture. At first, many blamed welding, but history would soon prove that
the real cause of brittle fracture was steels that were notch sensitive
at operating temperatures. The steel was found to have high sulfur and
phosphorus contents. On more than 1400 ships, crack arrestors were used
to prevent crack propagation. No crack was known to grow past an
arrestor. This safeguard helped reduce casualties from 140 to 20 per month.

The ASME Code
In the late 1920s and early 1930s,
the welding of pressure vessels came on the scene. Welding made possible a quantum
jump in pressure attainable because the process eliminated the low structural
efficiency of the riveted joint. Welding was widely utilized by industry as it
strove to increase operating efficiencies by the use of higher pressures and
temperatures, all of which meant thick-walled vessels. But before this
occurred, a code for fabrication was born from the aftermath of catastrophe.
On April 27, 1865, the steamboat
Sultana blew up while transporting 2200 passengers on the Mississippi River.
The cause of the catastrophe was the sudden explosion of three of the
steamboat's four boilers, and up to 1500 people were killed as a result. Most
of the passengers were Union soldiers homeward bound after surviving
Confederate prison camps. In another disaster on March 10, 1905, a fire tube
boiler in a shoe factory in Brockton, Mass., exploded, killing 58, injuring 117
and causing damages valued at $250,000. These two incidents, and the many
others between them, proved there was a need to bring safety to boiler operation.
So, a voluntary code of construction went into effect in 1915 - the ASME Boiler
Code.
As welding began to be used, a need
for nondestructively examining those welds emerged. In the 1920s, inspectors
tested welds by tapping them with hammers, then listening to the sound through
stethoscopes. A dead sound indicated a defective weld. By 1931, the revised
Boiler Code accepted welded vessels judged safe by radiographic testing. By
this time, magnetic particle testing was used to detect surface cracks that had
been missed radiographic testing. By this time, magnetic particle testing was
used to detect surface cracks that had been missed by radiographic inspection.
In his history of the ASME Code, A. M. Greene, Jr., referred to the late 1920s
and early 1930s as "the great years." It was during this period that fusion
welding received widespread acceptance. Nowadays, thousands of individuals
who make their living in welding live and breathe the ASME Code every minute of
the working day.
In 1977, Leonard Zick, chairman of
the main committee of the ASME Code, said, "It's more than a code; the
related groups make up a safety system. Our main objective is to provide
requirements for new construction of pressure-related items that, when
followed, will provide safety to those who use them and those who might be
affected by their use. "

LNG
Tankers
A triumph of the code was the huge
aluminum spheres built by General Dynamics in Charleston, S.C. They were built
to criteria established by the U.S. Coast Guard and were based on Section VIII,
Division 1, of the ASME Code.
At about 2 a.m. on October 2, 1976, the
first welded aluminum sphere for a liquefied natural gas tanker was rolled out
of a building in Charleston, then moved over to a special
stand for final hydropneumatic
testing. It soon passed the test with flying colors. The sphere itself weighed
850 tons and measured 120 ft (36 m) in diameter. Each sphere consisted of more
than 100 precisely machined plates, "orange peel" in shape. The
plates were gas metal arc welded together using 7036 lb (3166 kg) of filler
metal. Total length of the welds on each sphere was 48.6 miles. Completed
spheres were barged along the coast and delivered onto steel tankers under
construction at General Dynamics' shipyard in Quincy, Mass. This type of LNG
tanker was based on the MossRosenberg design from Norway.
At General Dynamics'
facility in Charleston, 80% of the metalworking manhours were spent welding.
Much of the filler metal deposited in Charleston was 5183 aluminum. The
vertical joints were welded using special equipment from Switzerland in which
the operator rode in a customdesigned chair alongside the welding arc. At this
distance, he was able to monitor the weld and observe the oscillation of the
1Z.5 -mm diameter filler metal. Actual welding was controlled remotely. About
30 weld passes were required for each joint.
The massive equatorial ring was
welded outdoors. In this setup, nine heavily machined, curved aluminum
extrusions had to be welded together. To do it, 88 GMA weld passes were made
from the outside and 60 more from the
inside.
The Alaska Pipeline
Perhaps no single welding event in
history ever received so much attention as did the Alaska Pipeline. Crews of
seasoned welders braved Alaska's frigid terrain to weld this large-diameter
pipeline, from start to finish. At one point, 17,000 people were working on the
pipeline - 6% of the total population of Alaska. The entire pipeline only
disturbed about 12 square miles of the 586,000 square miles of the state of
Alaska.
Welders were
called upon to handle and weld a new steel pipe thicker and larger than most of
them had ever encountered before, using electrodes also new to most. And, the
requirements were the stiffest they had ever seen.
The U.S. Department of the Interior
and a new pipeline coordinating group representing the state of Alaska instituted
some changes. So, the original specifications for field welding were
tossed, replaced by much stiffer requirements for weld toughness.
Instead of the conventional pipeline welding electrode planned originally for
the bulk of field welding, the new requirements required higher quality. The
only electrode the engineers could find that met the new requirements was an
E8010-G filler metal from Germany, so it was soon flown over by the planeload.
Some of the Pipeline Welders Union out of Tulsa, Okla., then welding in Alaska,
had used this electrode while working on lines in the North Sea, but most
welders were seeing it for the first time.
One of the requirements was 100% X-ray
inspection of all welds. The films were processed automatically in vans
that traveled alongside the welding crews.
Welders worked inside protective
aluminum enclosures intended to protect the weld joint from the wind. Lighting
inside the enclosures enabled welders to see what they were doing during
Alaska's dark winter.
On the main pipeline,
preheat and the heat between weld passes was applied at first by spider-ring
burners. Induction heating was used later during construction.

High-Rise Construction
About 30 years ago, steel construction
went into orbit. The 100-story John Hancock Center in Chicago and the 110-story
twin towers of New York's World Trade Center were under construction. Above
ground, the World Trade Center required some 176,000 tons of fabricated structural
steel. The Sears Tower came later. Bethlehem Steel Corp. had received
orders for 200,000 tons of rolled steel products for the South Mall
complex in Albany, N.Y. Allied Structural Steel Co. was reported to have used
multiple-electrode gas metal arc welding in the fabrication of the First
National Bank of Chicago Building.
In a progress report on the erection
of the critical corner pieces for the first 22 floors of the 1107-ft (332-m)
high John Hancock Center, an Allied Structural Steel spokesman said various
welding processes were being used in that portion of the high-rise building.
More than 12,000 tons of structural steel were used in that section. Webs and
flanges for each interior H column were made up of A36 steel plate with
thicknesses up to 6172 in. (16.5 cm). The long fillet welds at the
web-to-flange contact faces were made using the submerged arc
process, while the box consumed in shop fabrication for this building, while
165,000 lb (74,250 kg) of weld metal was consumed during field erection. Weld metal
consumption in shop fabrication for the U.S. Steel Building in Pittsburgh,
Pa., reached 609,000 lb (274,050 kg).
During this same period, Kaiser
Steel Corp. had used the consumable guide version of electroslag welding
to deposit 24,000 welds in the Bank of America world headquarters building in
San Francisco. At the time, this building was regarded as the tallest earthquake-proof
structure ever erected on the West Coast. In terms of welding, one of the most
intensive structures built during this period was NASA's Vertical Assembly
Building on Merritt Island, Fla. Shop-welded sections for this giant structure
consumed 830,000 lb (373,500 kg) of weld metal.
For the World Trade Center, Leslie
E. Robertson, a partner in charge of the New York office of Skilling, Helle,
Christiansen, Robertson, said a computer was used to produce the drawing lists,
beam schedules, column details and all schedules for exterior wall panels.
Millions of IBM cards were then sent to every fabricator. These cards gave
fabricators the width, length, thickness and grade of steel of every
plate and section in all of the columns and panels. "In addition," he
said, "the fabricators are given all of the requirements of every weld
needed to make up the columns and panels. Many of these cards are used as equable
to the production of drawings. They are sent directly from the designer to
the fabricators. Draftsmen never become involved."
Elsewhere in New York City, Leo
Plofker, a partner in one of the city's leading design engineering firms,
extensively used welding in design. Among Plofker's achievements are the Pan-Am
Building and the all-welded, 52-story office building known as 140 Broadway.
"Our decision to make extensive use of welding is strictly based on
economics," he said. "Welded design results in savings in steel.
Field welding can cause some problems, but they are not too serious as long as
you maintain control over the welders and you insist that qualified personnel
be employed to perform nondestructive testing of the welds."

After-reading activity

Find the following sentences in the text and express in
your own words what they mean:
1.   Nowadays,
thousands of individuals who make their living in welding live and breathe
the ASME Code every minute of the working day.
2.   A. M. Greene,
Jr. referred to the late 1920s and early 1930s as "the great
years."
3.   About 30 years
ago, steel construction went into orbit.
4.   Welded design
results in savings in steel.
5.   In the late
1920s and early 1930s, the welding of pressure vessels came on the scene.

6.   In 1977,
Leonard Zick, chairman of the main committee of the ASME Code, said, “It's
more than a code… ;”

Fill in the blanks:

1.   Before
welding,  … was the main  assembly method in constructing standard merchant
ships.
2.   … was the
fastest welding process for joining steel plate in 1940s.
3.   The first
quality inspectors used … to tap the metal and hear the noise.
4.   The use of
higher pressures and temperatures made it necessary to construct … vessels.
5.   Magnetic
particle testing was more efficient than radiographic testing in detecting …  .

6.   The use of IBM
cards during the construction of the World Trade Center made it possible not to
involve … .
7.   In case of X-ray
inspection one has to process … .

Speaking

True or false?

1.
In 1940s all the welding techniques known were fast enough to
produce ships.
2.
Americans lost a lot of ships because of problems associated with
welding.  3. Introduction of welding into the high pressure and temperature
structures construction made it possible to make a great advance in industry.
4. The ASME Code was introduced to ensure safety in boiler production.
5. Draftsmen played an important part in the construction of
the World Trade Center.

PART
3. WELDING PROCESSES & EQUIPMENT

Lead-in
You already know what kind of training you should go
through to become welder. Among other things, a welder should know about
processes which are similar to welding. Look through the vocabulary and the
text below and say what the main difference between welding and related metal
joining processes is.

Vocabulary

soldering

пайка; пайка мягким
  (легкоплавким) припоем

tinning

лужение; облуживание

leading

свинцевание

brazing

1) пайка твердым припоем
  (из меди и цинка) 2) покрытие медью

sweat

паять, запаивать,
  припаивать (in, on)

gimmick

1) сложное приспособление
  Syn: gadget 2) а) прием, трюк, уловка, ухищрение, хитрость

filler metal

присадочный металл,
  присадка

filler rod

присадочный пруток;
  присадочная проволока

heat buildup

теплообразование,
  тепловведение

heat distortion

деформация (материала)
  из-за теплового нагрева

stitch welding

прерывистая шовная сварка;
  точечная сварка перекрывающимися точками; автоматическая точечная сварка

Reading

Text 1. Introduction to Welding Processes &
Equipment
Among the first things a new welder needs
to understand, is what the different kinds of welding processes and equipment
are, and their application.
A quick rundown:
Terms:

Soldering: Bonding by
melting a soft metal to the surface of pieces to be joined. Low temperature.
Good for joining dissimilar materials. Most common solders are lead-tin
alloys.
Tinning: A soldering process, where the surface of a
metal is coated with solder.
Leading: A form of soldering, solder is used to
fill in the surface of metal.  Brazing: Similar to soldering, but uses a
higher temperature to fuse the filler metal to the work pieces. Stronger bond.
(Includes "Silver Soldering") Work heated to pre-melt temperatures.
Welding: Joining 2 similar work pieces by melting
them together, usually with an additional filler rod of some sort to take up
space. Materials must be similar.
Cutting: Work is heated to melting point and beyond,
and "cut" by oxidizing metal. (Literally burning it away).
Shield: A barrier to keep oxygen away from
heated work to prevent oxidation. Includes chemical coatings called flux
(liquids, pastes, solids, which may be vaporized into a barrier gas when
heated), and inert gasses.
Oxidation of the surfaces will prevent proper bonding
of the metals.

Gas Welding

Uses Flame from burning gas to create welding heat.
Propane torch: (Soldering,
heating) Good for sweating pipes, starting fires, and spending hours trying
to heat frozen bolts, while the surrounding metal gets just as hot.
Oxyacetylene torch: (Cutting, welding,
brazing, soldering, leading) Most universal and useful welding tool. (Uses
Acetylene gas and Oxygen for hot flame) With the right bits, rod, and
technique, you can weld almost anything. Good for cutting anything from sheet
metal to the turret off a tank, lead filling, brazing (a sort of hard soldering
process) welding plate, welding sheet metal, welding aluminium, heating frozen
bolts, or alternately cutting them off, drilling holes in plate, welding cast
iron, shrinking and forming steel, and can double as a flame thrower in a
pinch. Drawbacks are: Overheating of some types of work, harder to control
quality of some processes.
Oxy-propane: (Soldering,
brazing, heating) A cheap compromise between low cost and portable propane,
and Oxy-Acetylene. Better than the former, not as good as the latter.
Arc welding

Uses an electric arc to create welding heat.
Basic AC & DC arc welders (AC is cheaper)
Uses flux coated steel (or other) rods of various types for different jobs.
Makes some of the best welds on heavy gauge steels and cast iron. Cutting rods
can make clean holes through thick stock, and are about the only thing which
can cut Kryptonite bike locks. Very difficult to weld thin metals. You can also
get a carbon arc torch to use on an arc welder to braze. Eastwood's "stitch"
welder is a gimmick used on an arc welder to buzz the rod in and out, which
may help on thinner stock. (learning how to weld better, or going to a
different process is usually a better idea.)
MIG (Metal Inert Gas): A DC arc welding process
which uses filler metal fed in the form of a spool of thin wire, shielded by
flow of inert gas (He, Argon) instead of flux used in Arc. Very fast, much
easier than Arc Welding, with less heat buildup. Very good for sheet
metal, due to minimal heat distortion. Harder to weld thick stock, as
welds are weaker due to poorer penetration. The modern choice for steel body
work, it can also be used for Aluminium with Argon as the shield gas.
TIG (Tungsten Inert Gas): A
high frequency AC arc process which uses a tungsten electrode shielded by an
inert gas to create a fine, controllable torch. Uses a separate filler rod, as
in Oxy-Acetylene welding. Capable of welding very thin metals. About the best
process for Aluminium, Stainless steel, and other exotic stuff.
Resistance welding:
includes spot welding: Uses the heat generated by electricity flowing
through work to melt and fuse. i.e.- put an electrode on either side of 2
overlapped sheets of steel, turn on power. Metal in between heats up, and melts
together. An old favorite for assembling car bodies.
Plasma Cutters: Not a welder, but related. A high
voltage arc is used to superheat and ionize a stream of air to the
"plasma" state. The stream of plasma makes a rapid, clean, narrow cut
with minimal heating of the work piece.

After-reading activity

Answer the following questions:

1.   What is the
main difference between soldering and brazing?
2.   What is used by
welders to prevent oxidation?
3.   What makes
soldering advantageous before welding?
4.   What welding
processes are suitable for welding thin/thick metal plates?
5.   What makes
plasma cutting better than gas cutting?

Vocabulary

coalescence

соединение, слипание;
  сращение

filler material

присадочный материал

molten pool

ванна расплавленного  металла, сварочная ванна

gas flame

газовое пламя

solid-phase

твёрдая фаза

ultrasonic

ультразвуковой

friction

трение

furnace                      печь

diffusion                    1)
рассеивание
2) диффузия
high-current
              сильноточный
low-voltage          низковольтный, низкого напряжения
discharge  разряд
arc column
                столб дуги
direct
current (dc)       постоянный ток
alternating
    current переменный ток
(ac)
layer                          слой;
пласт; ряд
molten-metal        капля жидкого металла droplet
flux                            флюс

inert atmosphere   инертная среда annulus  тех. узкое
кольцо (зазор и т. п.)
torch                               сварочная
горелка (для автоматической сварки –
головка)
base metal   основной металл grain  зерно
precipitation         осаждение residual stress        остаточное
напряжение

Find
the English equivalents for the following words and word combinations: источник
тепла, расплавленный металл, необходимый размер, сварной шов,       не      нагретый
         металл,       механические      свойства,    максимум температуры,        защищать
         поверхности,       быстрое      охлаждение, осуществлять    контроль,          препятствовать
   окислению,          вступать     в химическую реакцию, термообработка,
бомбардировка электронами, зона термического [теплового] воздействия, общая
потребляемая энергия

Reading

Text 2. Basic Principles
of Welding

A weld can be defined as a coalescence
of metals produced by heating to a suitable temperature with or without the
application of pressure, and with or without the use of a filler material.

In fusion welding a heat source
generates sufficient heat to create and maintain a molten pool of metal
of the required size. The heat may be supplied by electricity or by a gas
flame. Electric resistance welding can be considered fusion welding because
some molten metal is formed.
Solid-phase processes produce
welds without melting the base material and without the addition of a filler
metal. Pressure is always employed, and generally some heat is provided.
Frictional heat is developed in ultrasonic and friction joining,
and furnace heating is usually employed in diffusion bonding.
The electric arc used in welding is
a high-current, low-voltage discharge generally in the range 10–2,000
amperes at 10–50 volts. An arc column is complex but, broadly speaking,
consists of a cathode that emits electrons, a gas plasma for current
conduction, and an anode region that becomes comparatively hotter than the
cathode due to electron bombardment. Therefore, the electrode, if consumable,
is made positive and, if nonconsumable, is made negative. A direct current
(dc) arc is usually used, but alternating current (ac) arcs can be
employed.
Total energy input in all welding
processes exceeds that which is required to produce a joint, because not all
the heat generated can be effectively utilized. Efficiencies vary from 60 to 90
percent, depending on the process; some special processes deviate widely from
this figure. Heat is lost by conduction through the base metal and by radiation
to the surroundings.
Most metals, when heated, react with
the atmosphere or other nearby metals. These reactions can be extremely
detrimental to the properties of a welded joint. Most metals, for example,
rapidly oxidize when molten. A layer of oxide can prevent proper bonding
of the metal. Molten-metal droplets coated with oxide become entrapped
in the weld and make the joint brittle. Some valuable materials added for
specific properties react so quickly on exposure to the air that the metal
deposited does not have the same composition as it had initially. These
problems have led to the use of fluxes and inert atmospheres.
In fusion welding the flux has a
protective role in facilitating a controlled reaction of the metal and then
preventing oxidation by forming a blanket over the molten material. Fluxes can
be active and help in the process or inactive and simply protect the surfaces
during joining.
Inert atmospheres play a protective
role similar to that of fluxes. In gas-shielded metal-arc and gas-shielded
tungsten-arc welding an inert gas — usually argon—flows from an annulus
surrounding the torch in a continuous stream, displacing the air from
around the arc. The gas does not chemically react with the metal but simply
protects it from contact with the oxygen in the air.
The metallurgy of metal joining is
important to the functional capabilities of the joint. The arc weld illustrates
all the basic features of a joint. Three zones result from the passage of a
welding arc: (1) the weld metal, or fusion zone, (2) the heat-affected zone,
and (3) the unaffected zone. The weld metal is that portion of the joint that
has been melted during welding. The heat-affected zone is a region adjacent to
the weld metal that has not been welded but has undergone a change in
microstructure or mechanical properties due to the heat of welding. The unaffected
material is that which was not heated sufficiently to alter its properties.
Weld-metal composition and the
conditions under which it freezes (solidifies) significantly affect the ability
of the joint to meet service requirements. In arc welding, the weld metal
comprises filler material plus the base metal that has melted.
After the arc passes, rapid cooling of the weld metal occurs. A one-pass weld
has a cast structure with columnar grains extending from the edge of the
molten pool to the centre of the weld. In a multipass weld, this cast
structure may be modified, depending on the particular metal that is being
welded.
The base metal adjacent to the weld,
or the heat-affected zone, is subjected to a range of temperature cycles, and
its change in structure is directly related to the peak temperature at any
given point, the time of exposure, and the cooling rates. The types of base
metal are too numerous to discuss here, but they can be grouped in three
classes: (1) materials unaffected by welding heat, (2) materials hardened by
structural change, (3) materials hardened by precipitation processes.
Welding produces stresses in
materials. These forces are induced by contraction of the weld metal and by
expansion and then contraction of the heat-affected zone. The unheated metal
imposes a restraint on the above, and as contraction predominates, the weld
metal cannot contract freely, and a stress is built up in the joint. This is
generally known as residual stress, and for some critical applications
must be removed by heat treatment of the whole fabrication. Residual stress is
unavoidable in all welded structures, and if it is not controlled bowing or
distortion of the weldment will take place. Control is exercised by welding
technique, jigs and fixtures, fabrication procedures, and final heat treatment.

After-reading activity

Complete the following sentences:

1. A characteristic feature of fusion welding is:
a) molten
metal               b) low-voltage discharge          c) inert atmosphere
2. Furnace heating is usually employed in
a) friction joining  b) diffusion bonding       c)
ultrasonic joining 3. The consumable electrode is made
a) negative  b) positive  c) neither
4. Total energy input in all welding processes is
a) is greater than required to produce a joint          b)
is smaller than required to produce a joint c) equals to required to produce a
joint
5. Reactions of most metals with the atmosphere or
other nearby metals can  1) improve the properties of a welded joint  b) make
the properties of a welded joint worse  c) never influence the properties of a
welded joint 6. The most common gas used in gas-shielded metal-arc and
gas-shielded tungsten-arc welding is
a) argon       b)
oxygen    c) carbon dioxide
7. If not controlled, residual stress results in
a) precipitation processes in welded structures,  b)
freezing of the weldmetal  c) bowing or distortion of the weldment.

True or false?

1.   There is always
a welding pool in solid-phase welding processes.
2.   Total energy
input in all welding processes is greater than needed to produce a weld.
3.   Reactions of
metals with the atmosphere or other nearby metals are favorable to the
properties of a welded joint.
4.   Fluxes and
inert atmospheres play a protective role and prevent oxidation.
5.   The
heat-affected zone is a region with unaltered properties.
6.   Residual stress
is present in all welded structures.

Answer the following questions:

1.       What
is a weld?
2.       How
can the heat be supplied for welding?
3.       Is
pressure employed in solid-phase processes?
4.       What
does an arc column consist of?
5.       How
is heat applied during welding?
6.       What
is the role of inert atmospheres?
7.       What
can make a joint brittle while welding?
8.       What
does the weld metal comprise in arc welding?
9.       What
is the base metal influenced by?
10.   How can
residual stress in welded structures be controlled?
Reading

Text 3. Characteristics of the Principal Welding
Processes

Welding is the
process of joining together pieces of metal or metallic parts by bringing them
into intimate proximity and heating the places of contact to a state of fusion
or plasticity. This leads to interpenetration of the atoms of the metals in the
weld zone, and a strong inseparable joint is formed after the metals have
cooled.
Welding finds
widespread application in almost all branches of industry and construction.
Welding is extensively employed in the fabrication and erection of steel
structures in industrial construction and civil engineering (frames of
industrial buildings, bridges, etc.), vessels of weldedplate construction
(steel reservoirs, pipelines, etc.) and concrete reinforcement.
Welding
processes may be classified according to the source of energy employed for
heating the metals and the state of the metal at the place being welded. A
master chart of the principal welding processes is shown on the next page.
In fusion welding the welding area is
heated by a concentrated source of heat to a molten state and filler metal must
be added to the weld. In accordance with the method applied for feeding the
filler metal to the weld, welding procedures are classified as manual,
semi-automatic or automatic welding.
Pressure welding processes involve the
heating of the metallic parts only to a plastic or lightly fused state and
forcing them together with external pressure. Pressure welding processes are
applied to metals which are capable of being brought to a plastic state by
heating or due to the action of external forces. It has been established that
in this process the most weldable metals prove to be those metals which have
higher thermal conductivity. Such metals more rapidly dissipate heat from the
weld zone and do not allow an excessively high temperature to be concentrated
in a small area (the latter may lead to considerable internal stress).
The quality of
the joint obtained in pressure welding depends to a great extent upon the
magnitude of the applied pressure and the temperature to which the metal is
heated at the moment of welding. The higher this temperature, the less unit
pressure will be required to produce the weld. Proper cleaning of the surface
to be joined is one of the main conditions for obtaining high-quality welds in
pressure-welding procedures.
After-reading activity Find equivalents in the
text for the following word combinations:

Welding is widely used, welded area, disperse heat, parts
made of steel, designing and producing metal structures, pressing together.
Translate the following sentences from
Russian into English using the information from the text:

1.
Взаимопроникновение атомов металлических  изделий под действием
высокой температуры и давления приводит к образованию сварного соединения.
2.
Сварка находит широкое применение во всех отраслях промышленности
и в строительстве.
3.
При сварке давлением лучше свариваются металлы с большей
теплопроводностью, а необходимым условием получения высококачественного
соединения является предварительная очистка свариваемых поверхностей.
4.
При сварке плавлением используется присадочный металл, подача
которого может осуществляться автоматически.
5.
Чем ниже температура нагрева металла, тем выше необходимое для
получения соединения давление.
6.
Изготовление и монтаж стальных конструкций невозможны без
применения сварки.
7.
Сварка широко применяется в строительстве для создания каркаса
зданий.
8.
По типу подачи присадочного материала сварочные процессы делятся
на ручные и механизированные.
9.
Концентрация высоких температур на малых участках
(неравномерность нагрева) приводит к появлению внутреннего напряжения в
металлах.
10.
Свариваемые детали должны находиться в непосредственной близости
друг от друга.

Use the information of the Master Chart of welding
processes above to complete the following sentences:

1.
The two basic welding processes are ... .
2.
The fusion processes consist of … .
3.
Among these, arc welding can be accomplished …
4.
Arc welding with consumable electrodes includes the following
types… .
5.
Carbon arc welding, atomic hydrogen welding, inert gas tungsten
arc welding refer to … .
6.
The pressure processes include … .
7.
Resistance welding is divided into three types … .

Translate the following text from Russian into English:

Cвaрка – это процесс получения
неразъёмного соединения деталей машин, конструкций и сооружений посредством
местного разогрева (вплоть до плавления), пластической деформации или при
совместном действии того и другого; суть сварки заключается в таком взаимном
проникновении или сближении поверхностей свариваемых тел, при котором в месте
соединения начинают действовать силы межатомного (межмолекулярного) сцепления.
Различают сварку плавлением (дуговая, газовая, плазменная, электроннолучевая,
лазерная) и сварку давлением (контактная, конденсаторная, холодная,
ультразвуковая, термокомпрессионная, диффузионная). Выбор того или иного
способа сварки зависит от физико-химических свойств свариваемых материалов,
условий проведения сварки, от толщины соединяемых деталей и конструкции
соединений.

Lead-in.

Remember all the welding types which you have read about
before and make a complete list of these types.
Think and say: What can be the difference between the
principle (“traditional”) and alternative types of welding? Why are traditional
welding processes not sufficient?

Vocabulary

cold welding

холодная сварка (в вакууме)

friction welding

сварка трением

laser welding

лазерная сварка

diffusion bonding

диффузное соединение

ultrasonic welding

ультразвуковая сварка

explosive welding

сварка взрывом

butt

стык

anvil

наковальня

honeycomb

пористый

fin

ребро, пластина

finished

готовый; обработанный

integrated circuitry

интегральная схемотехника

fuse

плавить, расплавлять

pneumatic tooling

пневматический инструмент

punch presses

пресс-штамп

Reading

Text 4. Alternative Types of Welding

Cold
welding
Cold welding,
the joining of materials without the use of heat, can be accomplished simply by
pressing them together. Surfaces have to be well prepared, and pressure
sufficient to produce 35 to 90 percent deformation at the joint is necessary,
depending on the material. Lapped joints in sheets and cold-butt welding
of wires constitute the major applications of this technique. Pressure can
be applied by punch presses, rolling stands, or pneumatic tooling.
Pressures of 1,400,000 to 2,800,000 kilopascals (200,000 to 400,000 pounds per
square inch) are needed to produce a joint in aluminum; almost all other metals
need higher pressures.

Friction
welding
In friction welding two work pieces
are brought together under load with one part rapidly revolving. Frictional
heat is developed at the interface until the material becomes plastic, at which
time the rotation is stopped and the load is increased to consolidate the
joint. A strong joint results with the plastic deformation, and in this sense
the process may be considered a variation of pressure welding. The process is
self-regulating, for, as the temperature at the joint rises, the friction
coefficient is reduced and overheating cannot occur. The machines are almost
like lathes in appearance. Speed, force, and time are the main variables. The
process has been automated for the production of axle casings in the automotive
industry.

Laser
welding
Laser welding is accomplished when
the light energy emitted from a laser source focused upon a workpiece to fuse
materials together. The limited availability of lasers of sufficient power for
most welding purposes has so far restricted its use in this area. Another
difficulty is that the speed and the thickness that can be welded are
controlled not so much by power but by the thermal conductivity of the metals
and by the avoidance of metal vaporization at the surface. Particular
applications of the process with very thin materials up to 0.5 mm (0.02 inch)
have, however, been very successful. The process is useful in the joining of
miniaturized electrical circuitry.

Diffusion
bonding
This type of bonding relies on the
effect of applied pressure at an elevated temperature for an appreciable period
of time. Generally, the pressure applied must be less than that necessary to
cause 5 percent deformation so that the process can be applied to finished machine
parts. The process has been used most extensively in the aerospace industries
for joining materials and shapes that otherwise could not be made—for example,
multiple-finned channels and honeycomb construction. Steel can be
diffusion bonded at above 1,000° C (1,800° F) in a few minutes.

Ultrasonic
welding
Ultrasonic joining is achieved by
clamping the two pieces to be welded between an anvil and a vibrating
probe or sonotrode. The vibration raises the temperature at the interface and produces
the weld. The main variables are the clamping force, power input, and welding
time. A weld can be made in 0.005 second on thin wires and up to 1 second with
material 1.3 mm (0.05 inch) thick. Spot welds and continuous seam welds are
made with good reliability. Applications include extensive use on lead bonding
to integrated circuitry, transistor canning, and aluminum can bodies.

Explosive
welding
Explosive welding takes place when
two plates are impacted together under an explosive force at high velocity. The
lower plate is laid on a firm surface, such as a heavier steel plate. The upper
plate is placed carefully at an angle of approximately 5° to the lower plate
with a sheet of explosive material on top. The charge is detonated from the
hinge of the two plates, and a weld takes place in microseconds by very rapid
plastic deformation of the material at the interface. A completed weld has the
appearance of waves at the joint caused by a jetting action of metal between
the plates.

After-reading activity

Match a welding type with its description

1. Cold welding

A. Light energy is used to
  weld parts together.

2. Friction welding

B.
  The weld is formed at the expense of the applied pressure at a high
  temperature for a long period of time.

3. Laser welding

C. Vibration is used to generate heat necessary to produce
  a weld. e

4. Diffusion bonding

D. The heat to accomplish
  the joint is generated by rotation.

5. Ultrasonic welding

E. The most important factor to accomplish the weld is
  pressure. No heat is applied.

6. Explosive welding

F. Rapid plastic deformation of the welded materials is
  caused by detonation.

Fill in the blanks with the right words (namely, types of
welding) from the list below:

1.   …welding is
successfully used in manufacture of small elements of electric circuits.
2.   Heat is not
used in … welding.
3.   … is widely
used in aerospace industries.
4.   Vibration is
used in …welding.
5.   Plastic
deformation is the basic principle in … welding.
6.   … welding is
impossible without pressure and high temperature.
7.   In … welding
one of the parts being welded revolves.

Translate the following sentences into Russian:

1.При         холодной    сварке        поверхности        должны
     быть  тщательно подготовлены.
2.
Скорость и толщина свариваемых деталей зависит не столько от
мощности лазера, сколько от теплопроводности металла.
3.
Этот вид сварки наиболее широко используется в авиакосмической
промышленности.
4.
Холодная сварка – это сварка без использования тепловой энергии,
когда две свариваемые поверхности, обладающие высокой пластичностью, с силой
прижимают друг к другу.
5.
Использование точечной и шовной сварки позволяет получать сварные
соединения высокой прочности.
6.
Основными переменными величинами при этом виде сварки являются
подводимое тепло, время сварки и сила сжатия.
7.
Фрикционным разогревом добиваются пластичности материала, затем
вращение цапфы останавливают и увеличивают давление для обеспечения сваривания
поверхностей.
8.
Сварной шов имеет чешуйчатый вид, что является результатом обдува
струей сжатого воздуха.
Writing

Make a summary of alternative welding processes indicating
their application capabilities. Start like this:

1. Cold welding that is welding
without heat makes it possible to join thin sheets of aluminum.  2. Friction
welding…

PART
4. ARC AND GAS WELDING IN DETAIL

Lead-in
Remember the definition and description of arc welding
from the previous chapters. What, in your opinion, makes arc welding one of the
two main welding processes so widely applied in modern industry?

Find the English equivalents for the following Russian
phrases in the text:

Постоянный/переменный ток,
электрическая дуга, присадочный материал, источник питания, положительно
заряженный анод, остатки флюса, волна типа "синусоида", гармоническая
волна/ прямоугольная волна, плавящийся электрод, свариваемые металлы,
пересечение нулевого уровня, пленка ПВХ, светофильтры, наплавка, горючие
материалы

Reading

Text 1. Arc Welding
Arc welding refers to a
group of welding processes that use a welding power supply to create an
electric arc between an electrode and the base material to melt metals at the
welding point. They can use either direct (DC) or alternating (AC) current, and
consumable or non-consumable electrodes. The welding region is sometimes
protected by some type of inert or semiinert gas, known as a shielding gas, and
filler material is sometimes used as well.

A constant current welding power
supply capable of AC and DC
Power supplies
To supply the electrical energy necessary
for arc welding processes, a number of different power supplies can be used.
The most common classification is constant current power supplies and constant
voltage power supplies. In arc welding, the voltage is directly related to the
length of the arc, and the current is related to the amount of heat input.
Constant current power supplies are most often used for manual welding
processes such as gas tungsten arc welding and

shielded metal arc welding, because they maintain a
relatively constant current even as the voltage varies. This is important
because in manual welding, it can be difficult to hold the electrode perfectly
steady, and as a result, the arc length and thus voltage tend to fluctuate.
Constant voltage power supplies hold the voltage constant and vary the current,
and as a result, are most often used for automated welding processes such as
gas metal arc welding, flux cored arc welding, and submerged arc welding. In
these processes, arc length is kept constant, since any fluctuation in the
distance between the wire and the base material is quickly rectified by a large
change in current. For example, if the wire and the base material get too
close, the current will rapidly increase, which in turn causes the heat to
increase and the tip of the wire to melt, returning it to its original
separation distance.
The type of current used in arc
welding also plays an important role in welding. Consumable electrode processes
such as shielded metal arc welding and gas metal arc welding generally use
direct current, but the electrode can be charged either positively or
negatively. In welding, the positively charged anode will have a greater heat
concentration, and as a result, changing the polarity of the electrode has an
impact on weld properties. If the electrode is positively charged, it will melt
more quickly, increasing weld penetration and welding speed. Alternatively, a
negatively charged electrode results in more shallow welds. Non-consumable
electrode processes, such as gas tungsten arc welding, can use either type of
direct current, as well as alternating current. However, with direct current,
because the electrode only creates the arc and does not provide filler
material, a positively charged electrode causes shallow welds, while a
negatively charged electrode makes deeper welds. Alternating current rapidly moves
between these two, resulting in medium-penetration welds. One disadvantage of
AC, the fact that the arc must be re-ignited after every zero crossing, has
been addressed with the invention of special power units that produce a square
wave pattern instead of the normal sine wave, making rapid zero crossings
possible and minimizing the effects of the problem.

Consumable electrode
methods
One of the most
common types of arc welding is shielded metal arc welding (SMAW), which is also
known as manual metal arc welding (MMA) or stick welding. Electric current is
used to strike an arc between the base material and consumable electrode rod,
which is  made of
steel and is covered with a flux that protects the weld area from
Shielded metal arc welding a pipe
                                                                                oxidation
    and     contamination     by
producing CO2 gas during the welding
process. The electrode core itself acts as filler material, making a separate
filler unnecessary. The process is very versatile, requiring little operator
training and inexpensive equipment. However, weld times are rather slow, since
the consumable electrodes must be frequently replaced and because slag, the
residue from the flux, must be chipped away after welding. Furthermore, the
process is generally limited to welding ferrous materials, though special
electrodes have made possible the welding of cast iron, nickel, aluminum,
copper, and other metals. The versatility of the method makes it popular in a
number of applications, including repair work and construction.
Gas metal arc welding (GMAW), also
known as metal inert gas (MIG) welding, is a semi-automatic or automatic
welding process that uses a continuous wire feed as an electrode and an inert
or semi-inert gas mixture to protect the weld from contamination. Since the
electrode is continuous, welding speeds are greater for GMAW than for SMAW.
However, because of the additional equipment, the process is less portable and
versatile, but still useful for industrial applications. The process can be
applied to a wide variety of metals, both ferrous and non-ferrous. A related
process, flux-cored arc welding (FCAW), uses similar equipment but uses wire
consisting of a steel electrode surrounding a powder fill material. This cored
wire is more expensive than the standard solid wire and can generate fumes
and/or slag, but it permits higher welding speed and greater metal penetration.

Submerged arc welding (SAW) is a
high-productivity welding method in which the arc is struck beneath a covering
layer of flux. This increases arc quality, since contaminants in the atmosphere
are blocked by the flux. The slag that forms on the weld generally comes off by
itself, and combined with the use of a continuous wire feed, the weld
deposition rate is high. Working conditions are much improved over other arc
welding processes, since the flux hides the arc and no smoke is produced. The
process is commonly used in industry, especially for large products.
Non-consumable electrode
methods

Gas tungsten arc
welding (GTAW), or tungsten inert gas (TIG) welding, is a manual welding
process that uses a nonconsumable electrode made of tungsten, an inert or
semi-inert gas mixture, and a separate filler material. Especially useful for
welding thin materials, this method is characterized by a stable arc and high
Gas tungsten arc welding                           quality welds, but it
requires significant operator   skill  and    can    only   be
accomplished at relatively low speeds. It can be used
on nearly all weldable metals, though it is most often applied to stainless
steel and light metals. It is often used when quality welds are extremely
important, such as in bicycle, aircraft and naval applications. A related
process, plasma arc welding, also uses a tungsten electrode but uses plasma gas
to make the arc. The arc is more concentrated than the GTAW arc, making
transverse control more critical and thus generally restricting the technique
to a mechanized process. Because of its stable current, the method can be used
on a wider range of material thicknesses than can the GTAW process, and furthermore,
it is much faster. It can be applied to all of the same materials as GTAW
except magnesium, and automated welding of stainless steel is one important
application of the process. A variation of the process is plasma cutting, an
efficient steel cutting process. Other arc welding processes include atomic
hydrogen welding, carbon arc welding, electroslag welding, electrogas welding,
and stud arc welding.
Safety issues
Welding, without the proper
precautions, can be a dangerous and unhealthy practice. However, with the use
of new technology and proper protection, the risks of injury and death
associated with welding can be greatly reduced. Because many common welding procedures
involve an open electric arc or flame, the risk of burns is significant. To
prevent them, welders wear protective clothing in the form of heavy leather
gloves and protective long sleeve jackets to avoid exposure to extreme heat and
flames. Additionally, the brightness of the weld area leads to a condition
called arc eye in which ultraviolet light causes the inflammation of the cornea
and can burn the retinas of the eyes. Goggles and helmets with dark face plates
are worn to prevent this exposure, and in recent years, new helmet models have
been produced that feature a face plate that self-darkens upon exposure to high
amounts of UV light. To protect bystanders, transparent welding curtains often
surround the welding area. These curtains, made of a polyvinyl chloride plastic
film, shield nearby workers from exposure to the UV light from the electric
arc, but should not be used to replace the filter glass used in helmets.
Welders are also often exposed to
dangerous gases and particulate matter. Processes like flux-cored arc welding
and shielded metal arc welding produce smoke containing particles of various
types of oxides. The size of the particles in question tends to influence the
toxicity of the fumes, with smaller particles presenting a greater danger.
Additionally, many processes produce various gases, most commonly carbon
dioxide and ozone, and fumes that can prove dangerous if ventilation is
inadequate. Furthermore, because the use of compressed gases and flames in many
welding processes pose an explosion and fire risk, some common precautions
include limiting the amount of oxygen in the air and keeping combustible
materials away from the workplace.
After reading activity
Match the terms and their meaning

1. Anode

A Fabrication process that joins
  materials, usually metals or thermoplastics, by causing coalescence

2. Ultraviolet
(UV) light

B Difference of
  electrical potential between two points of an electrical network, expressed
  in volts [1]. It is a measure of the capacity of an electric field to cause
  an electric

current in an electrical
  conductor.

3. Flux

C Electrical current
  whose magnitude and direction vary cyclically, as opposed to direct current,
  whose direction remains constant.

4. Welding

D (from the Greek
  άνοδος = 'going up') is the electrode in a
  device that electrons flow out of to return to the circuit. Literally, the
  path through which the electrons ascend out of an electrolyte solution. The
  other charged electrode in the same cell or device is the cathode.

5. Alternating current (AC)

E In metallurgy, a
  substance which facilitates soldering, brazing, and welding by chemically
  cleaning the metals to be joined. Common ….s are: ammonium chloride or rosin
  for soldering tin; hydrochloric acid and zinc chloride for soldering
  galvanized iron (and other zinc surfaces); and borax for brazing, and welding
  ferrous metals.

6. Carbon dioxide

F Atmospheric gas
  comprised of one carbon and two
oxygen atoms. A very widely known chemical
  compound, it is often referred to by its formula CO2. It is present in the
  Earth's atmosphere at a low concentration and acts as a greenhouse gas. In
  its solid state, it is called dry ice. It is a major component of the carbon
  cycle.

7. Oxidation

G Loss of an
  electron by a molecule, atom or ion

8. Goggles and safety glasses

H (Formerly wolfram)
  is a chemical element that has the symbol W (L. wolframium) and atomic number
  74. A very hard, heavy, steel-gray to white transition metal, it is found in
  several ores including wolframite and scheelite and is remarkable for its
  robust physical properties, especially the fact that it has a higher melting
  point than any other nonalloy in existence. The pure form is used mainly in
  electrical applications but its many compounds and alloys are widely used in
  many applications (most notably in light bulb filaments, and as both the
  filament and target in most X-ray tubes and in space-age superalloys).

9. Ozone

I In metallurgy a
  ferrous alloy with a minimum of 10% chromium content. The name originates
  from the fact that it does not stain, corrode or rust as easily as ordinary
  steel. This material is also called corrosion resistant steel when it is not
  detailed exactly to its alloy type and grade, particularly in the aviation
  industry.

10. Toxicity

J also known as arc
  flash, welder's flash, corneal flash

burns, or flash burns, is a
  painful ocular condition sometimes experienced by welders who have failed to
  use adequate eye protection. It can also occur due to light from sunbeds,
  light reflected from snow (known as snow blindness), water or sand. The
  intense ultraviolet light emitted by the arc causes a superficial and painful
  keratitis.

11. Stainless steel

K Triatomic
  molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that
  is much less stable than the diatomic species O2. It is a pale blue gas at
  standard temperature and pressure. It forms a dark blue liquid below
  −112 °C and a dark blue solid below −193 °C. A powerful oxidizing
  agent. It is also unstable, decaying to ordinary diatomic oxygen: 2 O3
  → 3 O2.

12. Arc eye

L From Greek
  τοξικότητα –
  poisonousness). It can refer to the effect on a whole organism, such as a
  human or a bacterium or a plant, or to a substructure, such as the liver. By
  extension, the word may be metaphorically used to describe toxic effects on
  larger and more complex groups, such as the family unit or "society at
  large". The skull and crossbones is a common symbol for it.

13. Tungsten

M Forms of
  protective eyewear that usually enclose or protect the eye area in order to
  prevent particulates or chemicals from striking the eyes. They are used in
  chemistry laboratories and in woodworking. They are often used in snow sports
  as well, and in swimming. Goggles are often worn when using power tools such
  as drills or chainsaws to prevent flying particles from damaging the eyes.

14. Voltage

N Electromagnetic
  radiation with a wavelength shorter than that of visible light, but longer
  than soft X-rays.

Speaking

True or false?

1.   Filler material
is always necessary for arc welding.
2.   The amount of
heat input at the welding point depends on the voltage.
3.   Shielded metal
arc welding is a consumable electrode process.
4.   Consumable
welding processes use any type of current.
5.   Consumable
electrode methods are faster than none-consumable ones.
6.   TIG welding
requires little operator training.
7.   Submerged arc
welding is used to weld large work pieces.

Answer the following questions and summarize the text:

1.       What
is arc welding?
2.       What
kind of current and electrodes are used in arc welding?
3.       What
is the welded region protected by?
4.       Why
is constant current power supply most often used for manual welding processes?
5.       How
does the type of the electrode charge (positive/negative) influence the speed
of welding and weld penetration?
6.       What
problem is related to the use of alternating current in gas tungsten welding?
7.       What
is the function of flux in shielded metal arc welding?
8.       What
are the main advantages and disadvantages of manual metal arc welding?
9.       Which
type of metal arc welding uses a separate filler material?
10.   What do the
welding protection clothes include?

Translate the following sentences from Russian into
English:

1.
Зона сварки при электродуговых процессах защищается защитным
газом.
2.
При сварке с использованием плавящихся электродов используется
как постоянный, так и переменный ток.
3.При РДС электрод является присадочным материалом.
4.
Благодаря разнообразию способов электродуговой сварки она находит
широкое применение в различных отраслях производства.
5.
Для защиты сварщиков от ультрафиолетового излучения электрической
дуги используются светофильтры.
6.
При недостаточной вентиляции газы могут представлять опасность
для здоровья.
7.
Благодаря отсутствию дыма при дуговой сварке под флюсом условия
труда гораздо лучше, чем при других способах электродуговой сварки.
8.
В целях предосторожности не следует держать воспламеняющиеся
предметы вблизи проведения сварочных работ.
.
Reading

Below find information about some less frequently
used arc welding processes. After reading the text, think and say why these
processes are less common in industry. Consider their advantages and
disadvantages.

Atomic Hydrogen Welding (AHW) is an arc welding
process that uses an arc between two metal tungsten electrodes in a shielding
atmosphere of hydrogen and without the application of pressure.  Shielding is
obtained from the hydrogen. Filler metal may or may not be used.  In this
process, the arc is maintained entirely independent of the work or parts being
welded.  The work is a part of the electrical circuit only to the extent that a
portion of the arc comes in contact with the work, at which time a voltage
exists between the work and each electrode.
Carbon Arc Welding (CAW) is a process which
produces coalescence of metals by heating them with an arc between a
nonconsumable carbon (graphite) electrode and the work-piece.  It was the first
arc-welding process ever developed but is not used for many applications today,
having been replaced by twin carbon arc welding and other variations.
Twin carbon arc welding (TCAW) in which the arc is
established between two carbon electrodes
Gas carbon arc welding (CAW-G) no longer has
commercial significance
Electroslag welding is a highly productive
welding process developed in the United States during the 1930s. It involves
the melting of the surfaces of the metal workpieces and the filler metal with a
molten slag to cause coalescence.  An electric arc is passed through the slag
to heat it, but the arc itself is extinguished by the slag. Electroslag welding
is commonly used to weld in a vertical orientation, and is particularly popular
with steels.  In the 1970s, it was used extensively in bridges, ships, and
other large metal structures.  However, in 1977 the Federal Highway
Administration banned its use in welds for some structural members of bridges,
due to concerns of weld imperfections and poor properties. Benefits of the
process include its high metal deposition rates. Many welding processes require
more than one pass for welding thick workpieces, but often a single pass is
sufficient for electroslag welding. The process is also very efficient, since
joint preparation and materials handling are minimized while filler metal
utilization is high.  The process is also safe and clean, with no arc flash and
low weld splatter or distortion.
Electrogas welding (EGW) is a continuous
vertical position arc welding process developed in 1961, in which an arc is
struck between a consumable electrode and the workpiece. A shielding gas is
sometimes used, but pressure is not applied. A major difference between EGW and
its cousin electroslag welding is that the arc in EGW is not extinguished,
instead remaining struck throughout the welding process. It is used to make
square-groove welds for butt and welding, especially in the shipbuilding
industry and in the construction of storage tanks. In EGW, the heat of the
welding arc causes the electrode and workpieces to melt and flow into the
cavity between the parts being welded. This molten metal solidifies from the
bottom up, joining the parts being welded together. The weld area is protected
from atmospheric contamination by a separate shielding gas, or by the gas
produced by the disintegration of a flux-cored electrode wire. The electrode is
guided into the weld area by either a consumable electrode guide tube, like the
one used in electroslag welding, or a moving head. When the consumable guide
tube is used, the weld pool is composed of molten metal coming from the parts
being welded, the electrode, and the guide tube. The moving head variation uses
an assembly of an electrode guide tube which travels upwards as the weld is
laid, keeping it from melting. Electrogas welding can be applied to most
steels, including low and medium carbon steels, low alloy high strength steels,
and some stainless steels. Quenched and tempered steels may also be welded by
the process, provided that the proper amount of heat is applied. Welds must be
vertical, varying to either side by a maximum of 15 degrees.  Like other arc
welding processes, EGW requires that the operator wear a welding helmet and
proper attire to prevent exposure to molten metal and the bright welding arc.
Compared to other processes, a large amount of molten metal is present during
welding, and this poses an additional safety and fire hazard. Since the process
is often performed at great heights, the work and equipment must be properly
secured, and the operator should wear a safety harness to prevent injury in the
event of a fall. EGW uses a constant voltage, direct current welding power
supply, and the electrode has positive polarity. A wire feeder is used to
supply the electrode, which is selected based on the material being welded. The
electrode can be flux-cored to provide the weld with protection from
atmospheric contamination, or a shielding gas can be used with a solid wire
electrode. The welding head is attached to an apparatus that elevates during
the welding process. Also attached to the apparatus are backing shoes which
restrain the weld to the width of the workpieces. To prevent them from melting,
they are made of copper and are water-cooled. They must be fit tightly against
the joint to prevent leaks.
Stud welding is a form of spot welding where a
bolt or specially formed nut is welded on to another metal part. The bolts may
be automatically fed into the spot welder. Weld nuts generally have a flange
with small nubs that melt to form the weld. Studs have a necked down,
unthreaded area for the same purpose.

Speaking

True or false

1.   Electrogas
welding is less hazardous than electroslag welding.
2.   Electroslag
welding is more frequently used to weld in a horizontal orientation.
3.   Carbon Arc
Welding is broadly used in industry in the present time.
4.   Filler metal is
always necessary in Atomic Hydrogen Welding.
5.   Quenched and
tempered steels are not welded using Electrogas welding.
6.   Carbon Arc
Welding is the newest arc welding process.

Answer the following questions:
1.   What kind of
electrodes are used in Electrogas and Atomic Hydrogen Welding processes?
2.   What structures
can be welded by Electrogas welding?
3.   Can thick
workpieces be easily welded by Electroslag welding?
4.   Why is
Electrogas welding relatively unsafe and hazardous?
5.   What is the
difference between Electrogas and Electroslag welding?
6.   Why does the
operator have to wear protective clothes?

Complete the following sentences:
1.   To ensure
safety while using arc welding processed operators have to wear… .
2.   Electroslag
welding is no more used to weld… .
3.   In Electrogas
welding the weld area is protected from atmospheric contamination … .
4.   In Atomic
Hydrogen Welding the work itself becomes… .
5.   Since
Electrogas welding is performed at great heigh… .

Writing

Write a short report arc welding mentioning:

Types (SMAW, MMA, GMAW, MIG, FCAW, SAW, GTAW, TIG,
electroslag welding, stud arc welding, EGW, TCAW);
Types of filler material used (consumable/none-consumable,
covered/bare electrode/wire);
Type of current used (direct/alternating);
Type of shielding gas used (helium, argon, CO2);
Major application areas.
Lead-in
Try to answer the following questions:

What is the difference in methods of gas gutting and
gas welding?
Is
there any difference in equipment used for gas welding and gas cutting? What
might be the advantages and disadvantages of gas cutting compared to other
methods of cutting metals?
Do you remember what appeared before: arc or gas
welding?
What type of cutting (arc or gas) is : a) more
expensive
b)  more operator skills
demanding
c)   safer
e)   faster
f)    more
precise?
Present your arguments.
Do you know what metals (steels) are better cut using
gas welding?

Vocabulary

rig

какое-л. приспособление, устройство, механизм Syn:
  apparatus , device

hose

шланг

spark

искра

igniter

воспламенитель

wrench

гаечный ключ

outfit

агрегат; оборудование, принадлежности, набор (приборов,
  инструментов)

pressure gauge

манометр

leak

течь, протечка; утечка

orifice

отверстие

single-stage (regulator)

однокамерный

flashback

обратный удар пламени (проникающий в шланг сварочной
  горелки)

Reading

Text 2. Oxygas Cutting Equipment

 An oxygas cutting outfit usually consists of a cylinder of
acetylene or MAPP gas, a cylinder of oxygen, two regulators, two lengths of hose
with

 In addition to the
basic equipment mentioned above, numerous types of auxiliary equipment are used
in oxygas cutting. An important item is the spark igniter that is used
to light the torch (figure at right, view A).
Another
item you use is an apparatus wrench. It is similar in design to the one shown
in figure at right, view B.

A Spark igniter and B Apparatus
wrench
 The apparatus wrench
is sometimes called a gang wrench because it fits all the connections on the
cutting rig. Note that the wrench shown has
A
portable oxygas cutting and  a raised opening in the handle that serves as
an welding outfit acetylene
tank key.
                                                                                Other
common accessories include tip
cleaners, cylinder trucks, clamps, and holding jigs.
Personal safety apparel, such as goggles, hand shields, gloves, leather aprons,
sleeves, and leggings, are essential and should be worn as required for the job
at hand.
 Oxygas cutting equipment can be stationary or
portable. A portable oxygas outfit, such as the one shown in figure above, is
an advantage when it is necessary to move the equipment from one job to
another.
 To conduct your cutting requirements, you must be
able to set up the cutting equipment and make the required adjustments needed
to perform the cutting operation. For this reason it is important you
understand the purpose and function of the basic pieces of equipment that make
up the cutting outfit. But, before discussing the equipment, let’s look at the
gases most often used in cutting: acetylene, MAPP gas, and oxygen.

Acetylene

 Acetylene is a
flammable fuel gas composed of carbon and hydrogen having the chemical formula
C2H2.When burned with oxygen, acetylene produces a hot flame, having a
temperature between 5700°F and 6300°F. Acetylene is a colorless gas, having a
disagreeable odor that is readily detected even when the gas is highly diluted
with air. When a portable welding outfit, similar to the one shown in figure
above is used, acetylene is obtained directly from the cylinder. In the case of
stationary equipment, similar to the acetylene cylinder bank shown in figure at
right, the acetylene can be piped to a number of individual cutting stations.
 Hazards: Pure acetylene is self-explosive if stored
in the free state under a pressure of 29.4 pounds per square inch (psi). A slight
shock is likely to cause it to explode.
WARNING: Acetylene becomes extremely dangerous if used
above 15 pounds pressure.

Cylinder
Design
 Acetylene can be safely compressed up to 275 psi when
dissolved in acetone and stored in specially designed cylinders filled with
porous material, such as balsa wood, charcoal, finely shredded asbestos, corn
pith, portland cement, or infusorial earth. These porous filler materials aid
in the prevention of high-pressure gas pockets forming in the cylinder.
 Acetone is a liquid chemical that dissolves large
portions of acetylene under pressure without changing the nature of the gas.
Being a liquid, acetone can be drawn from an acetylene cylinder when it is not
upright. You should not store acetylene cylinders on their side, but if they
are, you must let the cylinder stand upright for a minimum of 2 hours before
using. This allows the acetone to settle to the bottom of the cylinder.

NOTE: Acetone contaminates the hoses, regulators,
torch, and disrupts the flame.
 Acetylene is measured in cubic feet. The most common
cylinder sizes are 130-, 290-, and 330-cubic-foot capacity. A common standard
size cylinder holds 225 cubic feet of acetylene. Just because a cylinder has a
225-cubic-foot
capacity does not necessarily mean it has 225 cubic
feet of acetylene in it. Because it is dissolved in acetone, you cannot judge
how much acetylene is left in a cylinder by gauge pressure. The pressure
of the acetylene cylinder will remain fairly constant until most of the gas is
consumed.
 An example of an acetylene cylinder is shown in
figure above. These cylinders are equipped with fusible plugs that relieve
excess pressure if the cylinder is exposed to undo heat. A common standard
acetylene cylinder contains 225 cubic feet of acetylene and weighs about 250
pounds. The acetylene cylinder is yellow, and all compressed-gas cylinders are
colorcoded for identification. More on the color coding of cylinders is covered
later in this lesson.
Mapp
Gas
MAPP (methylacetylene-propadiene) is
an all-purpose industrial fuel having the high-flame temperature of acetylene
but has the handling characteristics of propane. Being a liquid, MAPP is sold
by the pound, rather than by the cubic foot, as with acetylene. One cylinder
containing 70 pounds of MAPP gas can accomplish the work of more than six and
one-half 225cubic-foot acetylene cylinders; therefore, 70 pounds of MAPP gas is
equal to 1,500 cubic feet of acetylene.
Cylinder
Design
Total weight for a MAPP cylinder,
which has the same physical size as a 225-cubic-foot acetylene cylinder, is 120
pounds (70 pounds which is MAPP gas). MAPP cylinders contain only liquid fuel.
There is no cylinder packing or acetone to impair fuel withdrawal; therefore,
the entire contents of a MAPP cylinder can be used. For heavy-use situations, a
MAPP cylinder delivers more than twice as much gas as an acetylene cylinder for
the same time period.
MAPP
Characteristics
 Because of its superior heat transfer
characteristics, MAPP produces a flame temperature of 5300°F when burned with
oxygen. MAPP equals, or exceeds, the performance of acetylene for cutting,
heating, and brazing. MAPP is not sensitive to shock and is nonflammable in the
absence of oxygen. There is no chance of an explosion if a cylinder is bumped,
jarred, or dropped. You can store or transport the cylinders in any position
with no danger of forming an explosive gas pocket. The characteristic odor,
while harmless, gives warnings of fuel leaks in the equipment long
before a dangerous condition can occur. MAPP gas is not restricted to a maximum
working pressure of 15 psig, as is acetylene. In jobs requiring higher
pressures and gas flows, MAPP can be used safely at the full-cylinder pressure
of 95 psig at 70°F. Because of this, MAPP is an excellent gas for underwater
work.
Bulk
MAPP Gas
Bulk MAPP gas facilities, similar to
liquid oxygen stations, are installed at some activities where large supplies
of the gas are used. In bulk installations, MAPP gas is delivered through a piping
system directly to the user points. Maximum pressure is controlled centrally
for efficiency and economy. Cylinder-filling facilities are also available from
bulk installations that allow users to fill their cylinders on site. Filling a
70-pound MAPP cylinder takes one man about 1 minute and is essentially like
pumping water from a large tank to a smaller one.
MAPP
Gas Safety
MAPP gas vapor is stable up to 600°F
and 1,100 psig when exposed to an 825°F probe. The explosive limits of MAPP gas
are 3.4 percent to 10.8 percent in air or 2.5 percent to 80 percent in oxygen.
As shown in figure 4-6, you can see these limits are narrow in comparison with
that of acetylene. MAPP gas has a highly detectable odor. The smell is
detectable at 100 ppm, or at a concentration of 1/340th of its lower explosive
limit. Small fuel-gas systems may leak 1 or 1 1/2 pounds of fuel or more in an
8-hour shift; bulk systems will leak even more. Fuel-gas leaks are often
difficult to find and often go unnoticed; however, a MAPP gas leak is easy to
detect and can be repaired before it becomes dangerous. MAPP toxicity is rated
“very slight,” but high concentrations (5,000 ppm) may have an anesthetic
effect. Local eye or skin contact with MAPP gas vapor causes no adverse effect;
however, the liquid fuel can cause dangerous frostlike burns due to the cooling
caused by the rapid evaporation of the liquid. The identification markings on a
MAPP cylinder are a yellow body with band “B” colored orange and the top
yellow.

Oxygen

Oxygen is a colorless, tasteless,
and odorless gas and is slightly heavier than air. It is nonflammable but
supports combustion with other elements. In its free state, oxygen is one of
the more common elements. The atmosphere is made up of about 21 parts of oxygen
and 78 parts of nitrogen, the remainder being rare gases. Rusting of ferrous
metals, discoloration of copper, and corrosion of aluminum are all due to the
action of atmospheric oxygen. This action is known as oxidation. Oxygen is
obtained commercially either by the liquid-air process or by the electrolytic
process. In the liquid-air process, the air is compressed and then cooled to a
point where the gases become liquid (approximately –375°F). The temperature is
then raised to above –321 ‘F, at which point the nitrogen in the air becomes
gas again and is removed. When the temperature of the remaining liquid is
raised to –297°F, the oxygen forms gas and is drawn off. The oxygen is further
purified and compressed into cylinders for use. The other process by which
oxygen is produced— the electrolytic process—consists of running an electrical
current through water to which an acid or an alkali has been added. The oxygen
collects at the positive terminal and is drawn off through pipes to a
container.
Oxygen is supplied for oxyacetylene
welding in seamless steel cylinders. The color of a standard oxygen cylinder
used for industrial purposes is solid green. Oxygen cylinders are made in
several sizes. The size most often used in welding and cutting is the 244-cubic-foot
capacity cylinder. This cylinder is 9 inches in diameter, 51 inches high, and
weighs about 145 pounds and is charged to a pressure of 2,200 psi at 70°F. You
can determine the amount of oxygen in a compressed gas cylinder by reading the
volume scale on the high-pressure gauge attached to the regulator.

Regulators

You must be able to reduce the
high-pressure gas in a cylinder to a working pressure before you can use it.
This pressure reduction is done by a regulator or reducing valve. The one basic
job of all regulators is to take the high-pressure gas from the cylinder and
reduce it to a level that can be safely used. Not only do they control the
pressure but they also control the flow (volume of gas per hour).
Regulators come in all sizes and
types. Some are designed for highpressure oxygen cylinders (2,200 psig), while
others are designed for lowpressure gases, such as natural gas (5 psig). Some
gases like nitrous oxide or carbon dioxide freeze when their pressure is
reduced so they require electrically heated regulators.
Most regulators have two gauges: one
indicates the cylinder pressure when the valve is opened and the other
indicates the pressure of the gas coming out of the regulator. You must open
the regulator before you get a reading on the second gauge. This is the
delivery pressure of the gas, and you must set the pressure that you need for
your particular job.
The pressures that you read on
regulator gauges is called gauge pressure. If you are using pounds per square
inch, it should be written as psig (this acronym means pounds per square inch
gauge). When the gauge on a cylinder reads zero, this does not mean that the
cylinder is empty. In actuality, the cylinder is still full of gas, but the
pressure is equal to the surrounding atmospheric pressure. Remember: no gas
cylinder is empty unless it has been pumped out by a vacuum pump.
There are two types of regulators that
control the flow of gas from a cylinder. These are either single-stage or
double-stage regulators.

Single-Stage Regulators           Regulators are
used on both high- and low-pressure systems. Figure at left shows two
SINGLE-STAGE regulators: one for acetylene and one for oxygen. The regulator
mechanism consists of a nozzle through which the gases pass, a valve seat to
close off the nozzle, a diaphragm,  and    balancing    springs.       These
mechanisms are all enclosed in a suitable housing.      Fuel-gas      regulators
   and    oxygen regulators are basically the same design. The

Single stage regulators

difference being those designed for fuel gases are not made
to withstand the high pressures that oxygen regulators are subjected to.
In the oxygen regulator, the oxygen
enters through the high-pressure inlet connection and passes through a glass
wool falter that removes dust and dirt. Turning the adjusting screw IN
(clockwise) allows the oxygen to pass from the high-pressure chamber to the
low-pressure chamber of the regulator, through the regulator outlet, and
through the hose to the torch. Turning the adjusting screw further clockwise
increases the working pressure; turning it counterclockwise decreases the
working pressure.
The high-pressure gauge on an oxygen
regulator is graduated from 0 to 3,000 psig and from 0 to 220 in cubic feet.
This allows readings of the gauge to determine cylinder pressure and cubic
content. Gauges are calibrated to read correctly at 70°F. The working pressure
gauge may be graduated in “psig” from 0 to 150, 0 to 200, or from 0 to 400,
depending upon the type of regulator used. For example, on regulators designed
for heavy cutting, the working pressure gauge is graduated from 0 to 400.
The major disadvantage of
single-stage regulators is that the working gas pressure you set will decrease
as the cylinder pressure decreases; therefore, you must constantly monitor and
reset the regulator if you require a fixed pressure and flow rate. Keeping the
gas pressure and flow rate constant is too much to expect from a regulator that
has to reduce the pressure of a full cylinder from 2,200 psig to 5 psig. This
is where double-stage regulators solve the problem.

Double-Stage
Regulators
The double-stage regulator is similar in principle to
the onestage regulator.
 The main difference being that the total pressure
drop takes place in two stages instead of one.
Double stage regulators                          In the high-pressure          stage,          the     cylinder
pressure is reduced to
an intermediate pressure that was predetermined by the
manufacturer. In the low-pressure stage, the pressure is again reduced from the
intermediate pressure to the working pressure you have chosen. A typical
double-stage regulator is shown in figure above.

Problems
And Safety
Regulators are precise and
complicated pieces of equipment. Carelessness can do more to ruin a regulator
than any other gas-using equipment. One can easily damage a regulator by simply
forgetting to wipe clean the cylinder, regulator, or hose connections. When you
open a highpressure cylinder, the gas can rush into the regulator at the speed
of sound. If there is any dirt present in the connections, it will be blasted
into the precision-fitted valve seats, causing them to leak. This results in a
condition that is known as creep. Creep occurs when you shut of the regulator
but not the cylinder and gas pressure is still being delivered to the
low-pressure side.
Regulators are built with a minimum
of two relief devices that protect you and the equipment in the case of
regulator creep or high-pressure gas being released into the regulator all at
once. All regulator gauges have blowout backs that release the pressure from
the back of the gauge before the gauge glass explodes. Nowadays, most
manufacturers use shatterproof plastic instead of glass. The regulator body is
also protected by safety devices. Blowout disks or spring-loaded relief valves
are the two most common types of devices used. When a blowout disk ruptures, it
sounds like a cannon. Spring-loaded relief valves usually make howling or
shrieking like noises. In either case, your first action, after you recover
from your initial fright, should be to turn off the cylinder valve. Remove the
regulator and tag it for repair or disposal. When opening a gas cylinder, you
should just “crack” the valve a little. This should be done before attaching
the regulator and every time thereafter. By opening the cylinder before
connecting the regulator, you blow out any dirt or other foreign material that
might be in the cylinder nozzle. Also, there is the possibility of a regulator
exploding if the cylinder valve is opened rapidly.
WARNING: Oil or other petroleum
products must never be used around oxygen regulators because these products
will either cause a regulator explosion or fire
Hoses

The hoses used to make the
connections between the torch and the regulators must be strong, nonporous,
light, and flexible enough to make torch movements easy. They must be made to
withstand internal pressures that can reach as high as 100 psig. The rubber
used in hose manufacture is specially treated to remove the sulfur that could
cause spontaneous combustion.
Welding hose is
available in single- and double-hose lengths. Size is determined by the inside
diameter, and the proper size to use depends on the type of work for which it
is intended. Hose used for light work has a 3/16 or 1/4 inch inside diameter
and one or two plies of fabric. For heavy-duty welding and cutting operations,
use a hose with an inside diameter of 5/16 inch and three to five plies of
fabric. Single hose is available in the standard sizes as well as 1/2-, 3/4-,
and 1-inch sizes. These larger sizes are for heavyduty heating and for use on
large cutting machines.
The most common type of cutting and
welding hose is the twin or double hose that consists of the fuel hose and the
oxygen hose joined together side by side. They are joined together by either a
special rib or by clamps.
Because they are joined together, the hoses are less
likely to become tangled and are easier to move from place to place.
The length of hose you use is
important. The delivery pressure at the torch varies with the length of the
hose. A 20-foot, 3/16-inch hose maybe adequate for a job, but if the same hose
was 50 feet long, the pressure drop would result in insufficient gas flow to
the torch. Longer hoses require larger inside diameters to ensure the correct
flow of gas to the torch. When you are having problems welding or cutting, this
is one area to check. The hoses used for fuel gas and oxygen are identical in
construction, but they differ in color. The oxygen hose cover is GREEN, and the
fuel-gas hose cover is RED. This color coding aids in the prevention of mishaps
that could lead to dangerous accidents.
All connections for welding and
cutting hoses have been standardized by the Compressed Gas Association. Letter
grades A, B, C, D, and E plus the type of gas used correspond directly with the
connections on the regulators. A, B, and C are the most common size
connections. A-size is for low-flow rates; B-size for medium-flow rates; and
C-size is for heavy-flow rates. D and E sizes are for large cutting and heating
torches.
When ordering connections, you must
specify the type of gas the hose will be carrying. This is because the
connections will be threaded differently for different types of gas. Fuel gases
use left-hand threads, while oxygen uses right-hand threads. The reason for
this is to prevent the accidental hookup of a fuel gas to a life-support oxygen
system or vice versa. The basic hose connection consists of a nut and gland.
The nut has threads on the inside that match up with the male inlet and outlet
on the torch and regulator. The gland slides inside the hose and is held in
place by a ferrule that has been crimped. The nut is loose and can be turned by
hand or a wrench to tighten the threaded nut onto the equipment.
Another important item that is often
overlooked is check valves. These inexpensive valves prevent personal injuries
and save valuable equipment from flashbacks. When ordering, make sure
you specify the type of gas, connection size, and thread design. The check
valves should be installed between the torch connection and the hose.

Cutting
Torches
The equipment and accessories for
oxygas cutting are the same as for oxygas welding except that you use a cutting
torch or a cutting attachment instead of a welding torch. The main difference
between the cutting torch and the welding torch is that the cutting torch has
an additional tube for highpressure cutting oxygen. The flow of high-pressure
oxygen is controlled from a valve on the handle of the cutting torch. In the
standard cutting torch, the valve may be in the form of a trigger assembly like
the one in figure below. On most torches, the cutting oxygen mechanism is
designed so the cutting oxygen can be turned on gradually. The gradual opening
of the cutting oxygen valve is particularly helpful in operations, such as hole
piercing and rivet cutting.

Torch Body
 Most welding torches are designed so the body of the
torch can accept either
One piece  oxygas cutting
torch                            welding
      tips    or      a cutting      attachment. This type of torch is called a
combination torch. The advantage of this type of torch is the ease in changing
from the welding mode to the cutting mode. There is no need to disconnect the
hoses; you just unscrew the welding tip and then screw on the cutting
attachment. The high-pressure cutting oxygen is controlled by a lever on the
torch handle, as shown in figure below.
Cutting Torch Tips
As in
welding, you must use the proper size cutting tip if quality work is to be
done. The preheat flames must furnish just the right amount of heat, and the
oxygen jet orifice must deliver the correct amount of oxygen at just the right
pressure and velocity to produce a clean cut. All of this must be done with a
minimum consumption of oxygen and fuel gases. Careless workers and workers not
acquainted with the correct procedures waste both oxygen and fuel gas.

Combination torch
Each manufacturer makes many different types of
cutting tips. Although the orifice arrangements and the tips are much the same
among the manufacturers, the part of the tip that fits into the torch head
often differs in design.
Because of these differences, there
is the possibility of having two or three different types of cutting torches in
your kits. Make sure that the cutting tips match the cutting attachment and
ensure that the cutting attachment matches the torch body.  Figure above shows
the different styles of tips, their orifice arrangements and their uses. The
tips and sears are designed to produce an even flow of gas and to keep
themselves as cool as possible. The seats must produce leakproof joints. If the
joints leak, the preheat gases could mix with the cutting oxygen or escape to
the atmosphere, resulting in poor cuts or the possibility of flashbacks.
To make clean and economical cuts,
you must keep the tip orifices and passages clean and free of burrs and slag.
If the tips become dirty or misshapened, they should be put aside for
restoration.

Tip
Maintenance
In cutting operations, the stream of
cutting oxygen sometimes blows slag and molten metal into the tip orifices
which partially clogs them. When this happens, you should clean the orifices
thoroughly before you use the tip again. A small amount of slag or metal in an
orifice will seriously interfere with the cutting operation. You should follow
the recommendations of the torch manufacturer as to the size of drill or tip
cleaner to use for cleaning the orifices. If you do not have a tip cleaner or
drill, you may use a piece of soft copper wire. Do not use twist drills, nails,
or welding rods for cleaning tips because these items are likely to enlarge and
distort the orifices.
Clean the orifices of the cutting
torch tip in the same manner as the single orifice of the welding torch tip.
Remember: the proper technique for cleaning the tips is to push the cleaner
straight in and out of the orifice. Be careful not to turn or twist the
cleaning wire. Figure above shows a typical set of tip cleaners.
Occasionally the cleaning of the
tips causes enlargement and distortion of the orifices, even when using the
proper tip cleaners. If the orifices become enlarged, you will get shorter and
thicker preheating flames; in addition, the jet of cutting oxygen will spread,
rather than leave the torch, in the form of a long, thin stream. If the
orifices become belled for a short distance at the end, you can sometimes
correct this by rubbing the tip back and forth against emery cloth placed on a
flat surface. This action wears down the end of the tip where the orifices have
been belled, thus bringing the orifices back to their original size.
Obviously, this procedure will not
work if the damage is great or if the belling extends more than a slight
distance into the orifice. After reconditioning a tip, you may test it by
lighting the torch and observing the preheating flames. If the flames are too
short, the orifices are still partially blocked. If the flames snap out when
you close the valves, the orifices are still distorted.
If the tip seat is dirty or scaled
and does not properly fit into the torch head, heat the tip to a dull red and
quench it in water. This will loosen the scale and dirt enough so you can rub
it off with a soft cloth.

Speaking

True or false?

1.   Oxygas cutting
outfit and cutting rig are different things.
2.   A gang wrench
is used to light the torch.
3.   Acetone has a
favourable effect on the cutting equipment.
4.   The acetylene
cylinder is painted blue.
5.   MAPP is a very
toxic gas.
6.   Acetone is a
solid body that dissolves large portions of acetylene under pressure.
7.   Cylinder valve
should be opened slowly to prevent explosion.
8.   Local eye or
skin contact with MAPP liquid fuel gas can cause dangerous frostlike burns.
9.   Twist drills,
nails, or welding rods must not be used for cleaning tips.

Continue the following sentences:
1.   An oxygas
cutting outfit usually includes… .
2.   The auxiliary
cutting equipment may consist of … .
3.   Acetylene is a
flammable fuel gas that has the following characteristics: …
4.   Acetone is a
liquid chemical that …
5.   MAPP is
characterized by …
6.   The action of
atmospheric oxygen, oxidation, manifests itself in …
7.   Personal safety
clothes for welders involved in cutting operation include … 8. The hoses that
connect the torch and the regulators must be … .

Translate the following sentences into English:

1.   Для правильного
использования сварочной аппаратуры сварщик должен знать назначение и функции ее
основных узлов.
2.   Для обеспечения
безопасности перед началом работы необходимо довести давление газа до рабочего
и отрегулировать пламя.
3.   Перед
присоединением регулятора к цилиндру необходимо удалить с сопла цилиндра пыль и
другие инородные материалы.
4.   Редукторы давления
выпускаются различных типов и размеров, как для цилиндров высокого, так и
низкого давления.
5.   Для
предотвращения случайной подачи топливного газа к кислородной системе и
наоборот используются соединения с разным направлением резьбы.
6.   При засорении
сопла резака пламя предварительного нагрева расширяется.
7.   Соприкосновение
редуктора давления с нефтепродуктами может вызвать взрыв или возгорание
последнего.
8.   По своим
рабочим характеристикам метилацетилен-аллен превосходит ацетилен при резке,
подогреве либо пайке.
9.   Редукторы
давления требуют тщательного ухода.
10.
Шланги для подачи горючего газа и кислорода маркируются разными
цветами и чаще всего скрепляются вместе для предотвращения спутывания.
11.
Баллон с газом не может считаться пустым, пока газ не будет
откачан насосом.
Compare operating characteristics of acetylene and MAPP
gas according to some of the parameters and fill in the table below:

Acetylene

MAPP

The
  gas is sold by
(pounds
  or cubic meters)

Cylinder
  packing (level of maximum
compression)

Stability (temperature)

Cylinders
  contain (pure fuel or not)

Dangerous    effects     on

health

Reading

Skim the text and do the tasks:
Text 3. Oxy-Fuel Welding
and Cutting
Oxy-fuel welding is a welding
process commonly called oxyacetylene welding since acetylene is the predominant
choice for a fuel, or often simply gas welding. A virtually identical
procedure, with a different type of gas torch, is used for cutting metal and
called oxy-fuel cutting. In gas welding and cutting, the heat energy and
high temperature needed to melt the metal is obtained by the combustion of a
fuel gas with oxygen in a torch. This sort of torch is often called a
blowtorch.

Compressed gas cylinders containing
oxygen oxygen and MAPP gas
Fuels
The most commonly used fuel gas is acetylene. Other gases
used are liquefied petroleum gas (LPG), natural gas, hydrogen, and MAPP gas.
Acetylene can be made near where the
welding is being done in an acetylene generator. More often it is made
elsewhere and shipped to the welding site in special containers. These
containers are packed with various porous materials (e.g. kapok fibre), then
filled about half way with acetone. The acetylene dissolves into the acetone.
This method is necessary because above 207 kPa (30 lbf/in²) acetylene is
unstable and may explode. There is about 1700

kPa (250 lbf/in²) of pressure in the tank when full.
Acetylene when burned with oxygen gives a temperature of 3200°C to 3500°C
(5800°F to 6300°F), which is the highest temperature of any of the commonly
used gaseous fuels.
Hydrogen has a clean flame and is good for
use on aluminum. It can be used at a higher pressure than acetylene and is
therefore useful for underwater welding. For small torches, hydrogen is often
produced, along with oxygen, by electrolysis of water in an apparatus which is
connected directly to the torch.
MAPP gas is a registered product of the
Dow Chemical Company. It is liquefied petroleum gas mixed with
methylacelylene–propadiene. It has the storage and shipping characteristics of
LPG and has a heat value a little less than acetylene.
Oxygen is not the fuel: It is what
chemically combines with the fuel to produce the heat for welding. This is
called 'oxidation', but the more general and more commonly used term is
'combustion'. In the case of hydrogen, the product of combustion is simply
water. For the other hydrocarbon fuels, water and carbon dioxide are produced.
The heat is released because the molecules of the products of combustion have a
lower energy state than the molecules of the fuel and oxygen.
Oxygen is usually shorted to 'oxy' for use
in the term 'oxy-acetylene torch'. Oxygen is usually produced elsewhere by
distillation of liquefied air and shipped to the welding site in high pressure
vessels (commonly called 'tanks' or 'cylinders') at a pressure of about 21000
kPa (3000 lbf/in² = 200 atmospheres). It is also shipped as a liquid in
Dewar type vessels (like a large Thermos jar) to places that use large amounts
of oxygen.
It is also possible to separate oxygen
from air by passing the air, while under pressure, through a zeolite sieve
which selectively absorbs the nitrogen and lets the oxygen (and argon) pass.
This gives a purity of oxygen of about 93%. This works well for brazing.
Apparatus
The apparatus used in
gas welding consists basically of a torch, two pressure regulators and twin
flexible hoses. The torch is the part that the welder holds and manipulates to
make the weld. It has two valves and two connections, one each for the fuel gas
and the oxygen, a handle for the welder to grasp, a mixing chamber

Two  types of oxy-gas torch head
where the fuel gas and oxygen mix, and a tip where the flame
issues from.
The regulators are attached to the fuel
and to the oxygen sources. The oxygen regulator is attached to the oxygen tank
and drops the pressure from about 21000 kPa (3000 lbf/in² = 200
atmospheres) to a lower pressure for the torch. This pressure can be adjusted
to suit the job at hand by turning a knob on the regulator, and can be set from
0 to about 700–1400 kPa (100–200 lbf/in²). Likewise the fuel regulator is
attached to the fuel source and drops the pressure to a level for the torch to
use. For acetylene this is 0 to 100 kPa (15 lbf/in²).
The flexible hoses connect from the
regulators to the torch and carry the fuel gas and the oxygen. The fuel gas
connections have left hand threads and the oxygen connectors have right hand
threads so that the two cannot be interchanged, so as to help prevent
accidents.
The welder wears goggles or a shield with
a shaded lens to protect his eyes from glare and flying sparks and splatter,
and wears leather gloves to help protect his hands from burns. He should also
wear clothes and shoes appropriate for welding. Sunglasses are not
adequate.
Note that the procedures and equipment
used for gas welding are essentially the same as for gas brazing.
]
Setting up the
equipment When using fuel and oxygen tanks
 they should be fastened securely to a wall, a
post or a portable cart in an upright
Oxygen
Rich Butane Blow Torch Flame position. An oxygen tank is especially
dangerous for the reason that the oxygen is
at a pressure of 21 MPa (3000 lbf/in² = 200
atmospheres) when full and if the  tank falls over and the valve strikes something and is
knocked off, the tank will become an unguided and unpredictable missile powered
by the compressed oxygen. It is for this reason that an oxygen tank should
never be moved around without the valve cap screwed in place.
 Never
lay the acetylene tank down while being used, as the acetone would start
Fuel Rich Butane
Blow Torch Flame to come out through the valve. If it was laid down
while being transported, it must be set upright, valve on top.
After the oxygen tank is securely
fastened, remove the valve cap. With the valve opening pointed away from the
welder, open the valve slightly for just a moment and then close it. This
serves two purposes. For one, it blows out any dirt or dust that may have settled
in the valve. This dirt would otherwise end up in the regulator and shorten its
life and accuracy. For another, when a tank is filled, the worker has a
tendency to tighten the valve securely to make certain it is closed completely.
It is better to break it loose now than when the regulator is in place. Attach
the oxygen regulator and tighten the nut. Never use pliers, as the pliers will
soon damage the brass nut; always use a wrench. Also, there is a tendency of
welders to over tighten the nut. If it is not leaking, then it is tight enough.
If a great amount of torque is needed to stop it leaking, or if it will not
stop leaking in spite of any amount of tightening, then there is something
wrong with the nut, the gasket or the valve.
Attach the fuel regulator to the fuel tank
in the same manner. The nut on the fuel regulator usually has left hand
threads.
Attach the flexible hoses from the
regulators to the torch. The oxygen hose is usually colored green and the fuel
hose red. The fuel hose has left hand threaded connectors at both ends and the
oxygen has right hand threaded connectors.
With the valves on the torch closed, and
the knobs on the regulators screwed out until loose (0 setting), open the
valves on the fuel and oxygen tanks. Open the oxygen valve slightly and then
wait while the high pressure gauge on the regulator stops rising. Then open the
valve fully, until it stops turning. This is a back stop valve. Turning the
valve all of the way out prevents leakage through the packing of the valve.
Open the fuel valve also. Only open an
acetylene valve one quarter turn. This helps prevent the acetylene from being
drawn off too quickly. If acetylene 'bubbles' too rapidly from the acetone, it
might become unstable. Open the valve on a LPG tank out completely as on an
oxygen tank and for the same reasons.
If there are any leaks in the connections,
regulators or torch, or any other faults with the equipment, a safety hazard
exists. The equipment should not be used.
Never oil an oxygen regulator. It will cause
a fire or explosion — solid brass regulators can be blown apart from the force.
Keep oxygen away from all combustibles.
The
flame
After this preparation, set the regulators
at the desired pressure. For acetylene, this should never be more than 103 kPa
(15 lbf/in²). To prevent a large yellow, sooty flame when first lighting
the torch, open both the fuel and the oxygen valves (more fuel than oxygen),
and light a flame with a 'striker' or by some other means. After the flame is
adjusted to the proper size, open the oxygen valve and adjust it to give the
desired balance of fuel and oxygen. Usually a neutral flame is used: this is a
flame where the fuel and oxygen supplied to the torch tip are both completely
combined with each other. An oxidizing flame has an excess of oxygen and a
reducing flame has an excess of fuel (carbon). An oxidising flame is used for
cutting and a reducing flame is used for annealing e.g. to soften steel sheet
metal.
An acetylene flame (as is characteristic
of most fuel/oxygen flames) has two parts; the light blue to white colored
inner cone and the blue colored outer cone. The inner cone is where the
acetylene and the oxygen combine. The tip of this inner cone is the hottest
part of the flame. The outer cone is where hydrogen and carbon monoxide from
the breakdown of the acetylene and partial combustion of the inner cone combine
with the oxygen in the surrounding air and burns.
A neutral flame has a well defined inner
cone. A reducing flame has a feathery inner cone. An oxidizing flame has a
smaller inner cone that is sharply defined and is pale blue. The welder
observes this while adjusting the fuel and oxygen valves on the torch to get
the correct balance for the job at hand. There is also a difference in the
noise the flame makes. Adjusting the flame is not a hard thing to do after a
little experience and practice.
The size of the flame can be adjusted to a
limited extent by the valves on the torch and by the regulator settings, but in
the main it depends on the size of the orifice in the tip. In fact, the tip
should be chosen first according to the job at hand, and then the regulators
set accordingly.
The flame is applied to the base metal and
held until a small puddle of molten metal is formed. The puddle is moved along
the path where the weld bead is desired. Usually, more metal is added to the
puddle as it is moved along by means of dripping metal from a wire
("welding rod" or "filler rod") into the molten metal
puddle. The force of the jet of flame issuing from the torch tip helps to
manipulate the puddle. The amount of heat can be controlled by the distance of
the flame from the metal. There should be a bright, incandescent spot on the
molten puddle. When the puddle is correctly maintained, a sound weld will
result.
The blowtorch

An old-fashioned kerosene blowtorch

A blowtorch is a special type of gas
welder. It has an additional lever on the handle that, when squeezed, supplies
an extra flow of oxygen out of a center hole in the mouthpiece. When the steel
is heated to its melting point, the extra flow of oxygen will burn (oxidise)
the molten iron and blow it away, effectively cutting the steel. The word
"blowtorch" is often used loosely to mean any sort of oxy-gas torch.
After reading activity

Match each term with its meaning

1. acetylene

A.
  A flammable fuel gas composed of carbon and hydrogen having the chemical
  formula C2H2.When burned with oxygen, it produces a hot flame, having a
  temperature between 5700°F and 6300°F. It is a colorless gas, having a
  disagree-able odor that is readily detected even when the gas is highly
  diluted with air. When a portable welding outfit, it is obtained directly
  from the cylinder. In the case of stationary equipment, it can be piped to a
  number of individual cutting stations.

2. oxygen

B.
  A chemical element with the chemical symbol O and atomic number 8. It is the
  second most common element on Earth, composing around 49% of the mass of
  Earth's crust and 28% of the mass of Earth as a whole, and is the third most
  common element in the universe. On Earth, it is usually covalently or
  ionically bonded to other elements.

3. hydrogen

C.
  A chemical element in the periodic table that has the symbol H and atomic
  number 1. At standard temperature and pressure it is a colorless, odorless,
  nonmetallic, univalent, tasteless, highly flammable diatomic gas (H2). With
  an atomic mass of 1.00794 g/mol, it is the lightest element. It is also the
  most abundant, constituting roughly 75% of the universe's elemental matter

4. acetone

D.
  In chemistry, (also known as propanone, dimethyl ketone, 2-propanone,
  propan-2-one and β-ketopropane) it is the simplest representative of the
  ketones. It  is a colorless mobile flammable liquid with melting point at
  −95.4 °C and boiling point at 56.53 °C. It has a relative density of
  0.819 (at 0 °C). It is readily soluble in water, ethanol, ether, etc., and itself
  serves as an important solvent. The most familiar household use of it is as
  the active ingredient in nail polish remover. It is also used to make
  plastic, fibers, drugs, and other chemicals.

5. aluminum

E.
  A silvery and ductile member of the poor metal group of chemical elements. In
  the periodic table it has the symbol Al and atomic number 13. It is found
  primarily in the bauxite ore and is remarkable for its resistance to
  corrosion (due to the phenomenon of passivation) and its light weight. It is
  used in many industries to manufacture a large variety of products and is
  very important to the world economy. Structural components made from this
  metal and its alloys are vital to the aerospace industry and very important
  in other areas of transportation and building.

6. carbon

F.
  A chemical element in the periodic table that has the symbol C and atomic
  number 6. An abundant nonmetallic, tetravalent element, it has several
  allotropic forms. It occurs in all organic life and is the basis of organic
  chemistry. This nonmetal also has the interesting chemical property of being
  able to bond with itself and a wide variety of other elements, forming nearly
  ten million known compounds. When united with oxygen it forms carbon dioxide,
  which is vital to plant growth. When united with hydrogen, it forms various
  compounds called hydrocarbons which are essential to industry in the form of
  fossil fuels.

7. oxy-gas torch

G.
  A blowtorch has several meanings, which deal with tools that consume fuel. It
  may mean a cutting torch, a handheld torch used for cutting metal.

8. natural gas

H.
  Commonly referred to as gas, is a gaseous fossil fuel consisting primarily of
  methane. It is found in oil fields and natural gas fields, and in coal beds.
  When methane-rich gases are produced by the anaerobic decay of non-fossil
  organic material, these are referred to as biogas. Sources of biogas include
  swamps, marshes, and landfills (see landfill gas), as well as sewage sludge
  and manure by way of anaerobic digesters, in addition to enteric fermentation
  particularly in

cattle.

Speaking

True or false?

1.   The only used
fuel gas in oxy-fuel welding is acetylene.
2.   'Oxidation' and
'combustion' are two terms which mean one and the same process.
3.   Oxygen is the
best fuel in oxy-fuel welding.
4.   The blowtorch
has two valves and one connection.
5.   The welder
wears goggles to protect his hands from burns.
6.   The procedures
and equipment used for gas welding and gas brazing are different.
7.   When setting up
the equipment, the valve cap is removed before the oxygen tank is fastened.
8.   Both pliers and
a wrench are used to tighten the nut of the regulator.
9.   Sunglasses can
be used instead of goggles to protect eyes from sparks and splatter.
10.
The size of the flame depends on the size of the orifice in the
tip and can be adjusted by the valves on the torch and by the regulator
settings.

Answer the following questions:

1.       What
are the other two names of the oxy-fuel welding process?
2.       What
does the high temperature needed to melt the metal obtained by?
3.       Is
acetylene always shipped to the welding site in containers?
4.       Why
is hydrogen useful for underwater welding?
5.       How
can hydrogen be produced for small torches?
6.       How
is oxygen delivered to the welding site?
7.       What
does the apparatus used in gas welding consist of?
8.       What
colour are the oxygen and fuel hoses?
9.       What
is a neutral flame?
10.   How many parts
does an acetylene flame have?

Use the plan to make a report about gas welding:

1.   Difference
between Oxy-fuel welding and oxy-fuel cutting.
2.   Fuel gases used
for gas welding.
3.   Parts of the
apparatus used in gas welding.
4.   Rules of
setting up the equipment
5.   Regulating
the flame.
Writing
Translate the following sentences from Russian into
English:
1.
Контактная сварка осуществляется нагревом или расплавлением
металлов при прохождении электрического тока в месте контакта сдавливаемых
изделий. Выполняется сжатием листовых заготовок между стержневыми электродами
(точечная контактная сварка) или вращающимися роликами (шовная контактная
сварка) либо прижатием торцов изделий (стыковая контактная сварка).
2.
Дуговая сварка (электродуговая сварка) -  вид сварки, при которой
кромки свариваемых металлических частей расплавляют дуговым разрядом между
электродом и металлом в месте соединения.
3.
Электронно-лучевая сварка -  сварка расплавлением материалов в
месте их соединения пучком электронов с энергией до 100 кэВ. Выполняется в
вакууме. Применяется для прецизионной сварки, сварки изделий из особо чистых,
разнородных или тугоплавких металлов (например, в микроэлектронике).
4.
Газовая сварка - способ сварки металлических изделий с помощью
газового пламени, образованного при сгорании смеси горючего газа (ацетилена,
водорода, паров бензина и др.) с кислородом. Применяют для сварки тонкостенных
изделий из стали, цветных металлов и сплавов, для наплавки твёрдых сплавов при
ремонтных работах.
5.
Электрошлаковая сварка - сварка плавлением металлов в месте
соединения. Источником нагрева металла служит теплота, которая выделяется при
прохождении электрического тока через расплавленный шлак, находящийся в зазоре
между соединяемыми деталями.
6.
Печная сварка (кузнечная, горновая) - соединение пластическим
деформированием (например, с помощью молота) металлических изделий, нагретых в
печах или горнах.
7.
Диффузионная сварка - производится сдавливанием предварительно
нагретых (без расплавления материалов) соединяемых деталей в вакууме, в
результате чего происходит диффузия атомов материалов контактирующих деталей.
Используют для сварки изделий из трудносвариваемых металлов, неметаллов,
пластмасс.
8.
Термитная сварка - технологический процесс, при котором зазор
между соединяемыми деталями, предварительно нагретыми до 400 — 700°C,
заполняется металлическим расплавом, полученным при сгорании термита.
Используется для сварки проводов, труб, рельсовых стыков.
9.
Газопрессовая сварка, соединение встык стержней, труб, фасонных
профилей и т. д. нагревом мест сварки газовым пламенем до оплавления или
пластического состояния металла и последующим сжиманием (осаживанием) соединяемых
частей.
10.
Высокочастотная сварка, сварка, при которой кромки свариваемых
деталей нагревают токами ВЧ до их размягчения или оплавления и сжимают. Ток в
изделии наводится индукционным или контактным способом. Используют, например,
для сварки труб из ленты.

PART 5. MODERN DEVELOPMENTS
Lead-in

Prior to reading text, say if the method described
below is a conventional one. What makes it conventional/unconventional?
Why does this welding process best fit for aluminium
and its alloys?
What should be changed in the parameters when shifting
from welding aluminium to steel?

Vocabulary

ductile         гибкий, ковкий, поддающийся
обработке threaded     с резьбой, нарезной
pin                                цапфа

shoulder
     буртик; поясок  debris   осколки, обломки; обрезки; лом  shrinkage
     усадочная деформация  solute          растворенное вещество,
раствор

Find the English equivalent sin the text for the
following Russian words and word combinations:

Традиционные технологии сварки, нагрев при трении,
выработка теплоты (тепловыделение), инструментальная оснастка, в
деформированном состоянии, нержавеющая сталь, шестивалентный хром, зона
термического влияния, накаленный докрасна, механическая обработка, элемент
конструкции.

Reading

Text 1. Friction Stir Welding (FSW)
H.H. Bhadeshia
Friction stir welding, a process
invented at TWI, Cambridge in 1991, involves the joining of metals without
fusion or filler materials. It is used already in routine, as well as critical
applications, for the joining of structural components made of aluminium and
its alloys. Indeed, it has been convincingly demonstrated that the process
results in strong and ductile joints, sometimes in systems which have proved
difficult using conventional welding techniques. The process is most suitable
for components which are flat and long (plates and sheets) but can be adapted
for pipes, hollow sections and positional welding. The welds are created by the
combined action of frictional heating and mechanical deformation due to a
rotating tool. The maximum temperature reached is of the order of 0.8 of the
melting temperature.

The tool has a circular section
except at the end where there is a threaded probe or more complicated
flute; the junction between the cylindrical portion and the probe is known as
the shoulder. The probe penetrates the work piece whereas the shoulder
rubs with the top surface. The heat is generated primarily by friction between
a rotating-translating tool, the shoulder of which rubs against the work piece.
There is a volumetric contribution to heat generation from the adiabatic
heating due to deformation near the pin. The welding parameters have to be
adjusted so that the ratio of frictional to volumetric
deformation--induced heating decreases as the work piece becomes thicker. This
is in order to ensure a sufficient heat input per unit length.
The microstructure of a
friction-stir weld depends in detail on the tool design, the rotation and
translation speeds, the applied pressure and the characteristics of the
material being joined. There are a number of zones. The heat-affected zone
(HAZ) is as in conventional welds. The central nugget region containing the
onion-ring flow-pattern is the most severely deformed region, although it
frequently seems to dynamically recrystallise, so that the detailed
microstructure may consist of equiaxed grains. The layered (onionring)
structure is a consequence of the way in which a threaded tool deposits
material from the front to the back of the weld. It seems that cylindrical
sheets of material are extruded during each rotation of the tool, which on a
weld cross-section give the characteristic onion-rings.
The thermomechanically-affected zone
lies between the HAZ and nugget; the grains of the original microstructure are
retained in this region, but in a deformed state. The top surface of the weld
has a different microstructure, a consequence of the shearing induced by the
rotating toolshoulder.
The
Machine
This is a  picture of
a friction stir welding (FSW shows a typical) machine. This one is at the
Joining and Welding Research Institute (JWRI) of Osaka University, Japan.

The Tool
An illustration of some types of
tools. Each tool has a shoulder whose rotation against the substrate generates
most of the heat required for welding. The pin on the tool is plunged
into the Friction-stir welding machine substrate and helps stir the metal
in the solid state.

The
Fixture and Weld
The two halves to be joined must be
rigidly fixed before the welding operation (first picture below). The pin,
which is an integral part of the tool, is plunged into the metal to help stir
it up; the shoulder of the tool generates much of the heat. As the weld
is completed, the tool is withdrawn leaving behind a hole. The weld is designed
so that such regions can be discarded from the component. The presence of a
hole may not be appropriate when welding pipes or storage vessels. The hole can
be avoided by designing the tool such that only the pin can be retracted
automatically and gently into the shoulder, leaving behind an integral weld.

FSW
of Steel
Steel can be friction stir welded
but the essential problem is that tool materials wear rapidly. Indeed, the wear
debris from the tool can frequently be found inside the weld. The
process would therefore be used in special circumstances where other welding
methods are inadequate. These circumstances have yet to be clarified. There are
so many good methods by which steel can be welded. The example below is the FSW
of 316L stainless steel. Notice that the sample becomes red-hot during welding.

Since the tool gets red hot, it is
necessary to protect it against the environment using a shielding gas. A possible
use of FSW in the welding of steels is in the context of stainless steels.
Austenitic stainless steels can easily be welded using conventional arc welding
and other processes. However, FSW can offer lower distortion, lower shrinkage
and porosity. More important is the avoidance of fumes containing hexavalent
chromium which is carcinogenic. In addition, chemical segregation effects
associated with welding processes involving solidification are avoided. Such
segregation can lead to a degradation of corrosion resistance since
electrochemical cells are set up between solute-rich and poor domains.
Friction
Stir Welding of Cast Aluminium Alloy
The most popular aluminium casting-alloy contains
about 8 wt% of silicon. It therefore solidifies to primary aluminium-rich
dendrites and a eutectic mixture of aluminium solid-solution and almost pure
silicon. The latter occurs as coarse silicon particles which tend to be brittle.
The cast alloy usually has some porosity. Friction stir welding has the
advantage that it breaks up the coarse silicon particles and heals any pores by
the mechanical processing, as illustrated below.

       A section through a friction stir weld made in
an Al-Si casting alloy. There are pores indicated in the base metal (BM). HAZ
represents the heat affected zone, TMAZ the thermomechanically affected zone,
and SN the stir nugget. The photographs in this section have kindly been
provided by Professor H. Fujii of JWRI, Japan.

Optical micrographs of regions (a), (b) and (c) of the
stir nugget. The location
of these regions is identified in macroscopic section
presented above. Optical micrographs showing the microstructure in (a) the base
metal; (b) heat-affected zone; (c) the thermo mechanically affected zone, where
considerable refinement of the silicon has occurred.
Tensile
strength Proof                stress Elongation (%)       Fracture local
(MPa)                     (MPa)

Joint
150               85                         1.6                        BM
Weld  179               87
                        5.3                        TMAZ
 SN      251               96                         14.4
                      SN
The refinement of silicon and elimination of porosity
leads to better mechanical properties in the weld than in the base plates.

True or false?

1.   FSW is not used
to weld steels.
2.   It’s impossible
to avoid holes in welds made by FSW method.
3.   The maximum
temperature reached during FSW is above the melting temperature.
4.   The
characteristics of the material being joined affect the microstructure of a
friction-stir weld.
5.   FSW is the only
method for welding austenitic stainless steels.
6.   Pipes can be
welded using FSW.

Translate the following sentences into English:

1.       При
сварке трением присадочный металл не используется.
2.       Получаемые
в результате сварки трением швы отличаются прочностью и пластичностью.
3.       Шов
при сварке трением образуется в результате нагрева при трении инструмента о
свариваемую деталь и возникновения механической деформации.
4.       Микроструктура
шва, полученного при помощи сварки трением, определяется целым рядом
параметров.
5.       Поверхность
шва внешне похожа на луковые кольца.
6.       Наличие
или отсутствие поры в зоне шва определяется конструкцией инструментальной
оснастки и скоростью отвода инструмента.
7.       Пары
шестивалентного хрома являются канцерогенными.
8.       Использование
сварки трением позволяет снизить усадочную деформацию и пористость.
9.       Существенным
недостатком данного метода является быстрый износ инструмента.
10.   При сваривании
стальных конструкций сталь раскаляется докрасна.

Make a short description of the method using the following
key words:

Fusion, filler material, aluminium and its alloys,
plates and sheets, frictional heating and mechanical deformation, rotating
tool, tool, shoulder, pin,  work piece, heat generation, microstructure
of a friction-stir weld, applied pressure, characteristics of the material,
withdrawal of the tool, onion-ring structure, HAZ, integral weld.

Vocabulary

hermal (heat) ageing

термостарение

bending test

испытание на изгиб

tensile (tension) test

испытание на растяжение

HAZ

heat affected zone зона термического влияния

butt joint

стыковое соединение;
  соединение встык

Abutment

торец; упор; опора,

Backing

опора

Reading

Read the text below and say what new facts you learn from
it.

Text 2. New Welding
Method for Aluminium

Friction welding has been used in
the manufacture of rotating bodies since 1956 and has become well-known as an
extremely rapid and reliable method. Unfortunately, its use has been limited to
rotationally symmetrical bodies, as friction welding is based the principle of
rotating two workpieces at high speed in relation to one another and then
pressing them against once another with great force, thereby rapidly obtaining
forging temperatures. As this method makes high productivity possible, the
opportunity to use friction welding for other types of object has been eagerly
awaited for many years.
Aluminium is normally welded using
MIG, TIG, plasma or manual welding with coated electrodes. A new welding
method, Friction Stir Welding, has been developed for welding aluminium. This
method has been patented and developed by TWI. The necessary expertise has been
acquired in a sponsorship project which has been run by TWI in collaboration
with possible users and machine-builders.
In principle, the method is based on
obtaining a sufficiently high temperature to forge two aluminium components,
using a rotating tool which moves along the joint. The temperature is under the
melting point of aluminium.
The aluminium components which are
going to be joined are clamped to a TIG using a powerful fixture. A tool with a
cylindrical shoulder and with a special profile is positioned above the centre
line of the joint. The tool is rotated at at a peripheral speed and is pushed
into the material with great force. The material comes plastic as a result of
the frictional heat and is forced to rise around the rotating probe until the
shoulder of the tool comes into direct contact with the surface of the
aluminium. When the tool is moved along the joint, the material is plasticised
by the frictional heat of the front of the rotating probe and moves behind the
probe, thereby forming a weld. This process continues as long as the tool is
moved along the joint.
The Friction Stir Welding of
alumimium 60 82 -T6 or SS 4212-06 has been shown to produce high strength
values. Typical values for the ultimate strength across joint are in the range
of 211-230 N/mm2, without ageing. Higher strength can be obtained by thermal
ageing. The specification for the base material is a minimum of 290 N/mm2.
Bending tests and tensile tests have been conducted without any negative
observations. Fractures took place in the base material HAZ.
Thick material. When welding
materials оf more than 15 mm, the welding is done from both sides. The maximum
thickness is around 30 mm at 100% penetration. The welding speed is
approximately 180 mm/min.
Welding speed. The welding speed
depends on the dimensions and the alloys which are used. The spindle speed also
affects the welding speed. For example, the welding speed in material 5 mm
thick can be 610 mm/min with a 60 82-T6 alloy.
Joint types. Butt joints and lap
joints can be welded. Corner joints and other special joints can also be
welded, but the method, accessibility, complete penetration requirements and so
on must be taken into account when they are planned.
Welding data. In Friction Stir
Welding, the welding parameters are dependent on the aluminium alloy, the
dimensions, the speed of the spindle and the traveling speed. In addition, the
design of the tool has an important effect on the welding result. Work on all
these parameters is in progress with the aim of building up data bank for the
progress in order to facilitate the use of Friction Stir Welding.
Working Environment. The working
environment is improved dramatically when Friction Welding is used. Welding
flash, fumes and ozone formation are totally eliminated. Steel brushing and
interpass cleaning are also unnecessary.
Advantages  The advantages of the
method are:
High, consistent quality.
Material thickness from 1.6-15 mm can be welded as
single-pass procedures.
Material from 15-30 mm can be welded on both sides.
No joint preparation, only degreasing.
No grinding or brushing.
No consumables.
No shielding gas.
Flat surface without weld reinforcement or splatter.
No magnetic blowing as the welding is done without an
arc.
Environmentally-compatible method without flash, fumes
or ozone formation. Less risk of pores and cracking as the temperature
never reaches the melting point of aluminium.
No burning off of alloy substance as the temperature
never reaches melting point.
Alloys which are difficult to weld can be welded as
there is only a small risk of hot cracking. High productivity.

Disadvantages

The method can only be used on
straight, flat workpieces or hollow profiles with an abutment or backing. The
method requires a stable welding machine with good reproducibility. Powerful
fixture which is able to hold the components in the correct position throughout
the welding operation. The back of the object must be accessible if 100%
penetration is necessary. As the method requires a stable welding machine with
a powerful fixture, the welding equipment should preferably be stationary. This
welding method leaves an end hole when the tool is pulled away from workpiece.
In many cases, this hole can be cut off, but, in other cases, it has to be
sealed using another method.

Applications

Suitable applications include
extruded aluminium profiles for: shipbuilding; offshore platforms; railway
wagons, trams and underground train carriages; the automobile, brewing, defense
industries; production of electric motors, cooling elements.

Summary

Friction Stir Welding is a new
welding method which enables two workpieces made of aluminium to be forged
using friction. The method has characteristics which make it extremely
interesting for the highly-productive joining of straight profiles and plates. In
the longer term, this method will help to extend the use of aluminium.

After reading activity

Use the words and phrases from the list below to fill
in the blanks in the sentences:

rotating bodies, manual welding, sponsorship project,
necessary expertise, in collaboration with, frictional heat, without any
negative observations, build up data bank, sufficiently high temperature,
environmentally-compatible

1.       …
is being replaced by automatic and semi-automatic types of welding in many
applications.
2.       They
could buy the new equipment only thanks to a successfully realized …  .
3.       …
are necessary elements of friction stir welding.
4.       The
new project was realized … foreign partners.
5.       In
order for the weld to be formed … in the welding area should be provided.
6.       After
the thorough repairs the equipment had been running for 2 years … .
7.       The
quality control supervisors had to carry out … before putting the welding
machine into operation.
8.       The
experience the engineers had in welding such structures helped them … necessary
for further development of the product.
9.       …
resulting from rotating bodies coming into direct contact can be removed by
special coolers.
10.   This new
welding machine is both operator friendly and … .

Speaking

Say if the following is an advantage or disadvantage of
friction stir welding:

1.   A hole is left
on the surface after the tool is pulled away from work piece.
2.   The welding
machine should be powerful and stable.
3.   The joint
doesn’t need special preparation.
4.   Flash, fumes
and ozone are not formed.
5.   Consumables and
shielding gas are not required.
6.   Abutment or
backing is necessary.
7.   Arc is not
used.

Answer the following questions:

1.   What is of
Friction Stir Welding method based on?
2.   How is the weld
formed?
3.   What do the
welding parameters depend on?
4.   What, in your
opinion, are the most important advantages/disadvantages of the Friction Stir
Welding method?
5.   Want is the
best sphere of application of this method at present?

Writing

Write a short report about FSW according to the following
plan:
1.   The principle
of FSW.
2.   Working
environment.
3.   Advantages and
disadvantages.
4.   Applications.

Lead-in

Think of the answers for the following questions:

1.   What is an
automated welding system?
2.   What might be
the advantages of automated welding systems compared with manual welding?
3.   What part do
you think can never be welded using automated welding?

Vocabulary

run

проход

man-machine communication

интерфейс человек-машина

automated system

автоматизированная система

welding sequence

последовательность сварки;
  порядок наложения швов

non-destructive testing

испытания  без     разрушения
          образца, неразрушающий контроль

interpass temperature

температура            начала
             мартенситных

превращений

weld bead

наплавленный валик сварного шва

log file

системный журнал

processing

обработка

Reading

Text 3. Man-machine
Communication for Multi-run Arc Welding

The multi-run welding of heavy
components imposes special demands on man-machine communication (MMC)
for automated welding systems. Welding sequences of
several hours with limited operator surveillance necessitate
pre-programming, not only of the nominal process data, but also of other
conditions for the successful performance of the welding process in varying external
conditions. Warnings of conditions requiring the operator's attention
must be given during welding. Should a situation occur in which the quality of
the weld is jeopardized, the process must be stopped in a controlled manner
and the reason for the stop must be displayed. Upon completion of the weld, a
presentation, indicating all the important events during the welding cycle,
should be made to determine the amount of nondestructive testing.
Provision should be made for further detailed investigations of optional parts
of the cycle, as well as for the storage and documentation of the course of the
process.
The operator interface for
the ESAB multi-run MMC is an industrial PC. The pre-programming modules
are divided into blocks of set-up parameters, process parameters,
warnings, reports and stop limits. Different sets of process parameters can be
automatically retrieved during the welding sequence. During welding, the screen
shows the preprogrammed parameters, the actual measured values and the way the
process is progressing (e.g. layer, bead and position).
If a warning is activated, the
operator is given the choice of immediately stopping the process stopping it
after the completion of the bead or allowing it to continue.
A small remote control box,
which can be hand-held, contains the controls the operator needs for preparing,
starting and stopping the process. The control system registers the welding
sequence in two separate files, the Weld Report and the multi-run. In the Weld
Report, all the installation parameters such as wire type and wire dimension,
flux (or gas) type and permissible inter-pass temperatures are stored, together
with the specified process parameters such as welding voltage, welding
current and welding speeds and their report, alarm and stop link.
All the important events during
welding, such as start, stop(s), restarts, exceeded report limits and warnings
for flux level, high or low interpass temperature, are stored in the Weld
Report. All the events are stored together with the actual date, time, weld
layer, weld bead and position in the joint. Should the event be an
exceeded process parameter, the parameters at the time in question are also
stored.
In the Log File, the position and
process parameters are continuously registered (every 20 mm). A normal Log File
report for a thick-walled welding object could fill 1,000 pages.
The Weld Report provides a good
overview of important events during welding. The reported events provide
valuable information for the planning of non-destructive testing and offer easily-accessible
documentation of the welding process. If further investigations are deemed
necessary, the Weld Report constitutes a good register for entering the Log
Files in which detailed information from the sectors associated with the
reported events can be found.
The multi-run control system can
also be connected to customers' central computer systems for documentation or
further processing of both Weld Reports and Log Files, together with
other quality control data.

After reading activity

Match the words and their translation:

1. operator surveillance

A текущая дата

2. external conditions

Bсила тока при
  сварке

3. operator's attention

C программируемые
  модули

4. in a controlled manner

D автоматически

5. operator interface

E внешние условия

6. pre-programming
  modules

F напряжение электрического тока при сварке

7. set-up parameters

G толстостенный

8. control box

H скорость сварки

9. welding voltage

I внимание оператора

10. welding current

J легкодоступный

11. welding speed

K контроль со
  стороны оператора

12. actual date

L блок управления

13. thick-walled

M установленные
  параметры

14. easily-accessible

N операторский
  интерфейс

Answer the following questions:

1.   What are the
functions of the described automated system?
2.   In what cases
must the welding process be automatically stopped?
3.   What does the
system do when the weld is completed?
4.   What do the
pre-programming modules include?
5.   What parameters
are displayed on the screen during the welding process?
6.   What can an
operator do when he receives a warning from the automated system?
7.   What does the
remote control unit contain?
8.   Where are all
the important events happening during the welding process stored?
9.   What is registered
in the log file?

Translate the following sentences into English:

1.
Использование автоматизированных сварочных систем позволяет легко
определить объем необходимого контроля качества.
2.
В случае возникновения угрозы качеству сварного шва сварочный
процесс немедленно прекращается.
3.
Оператор может контролировать подготовку, начало и завершение
сварочных операций с помощью пульта дистанционного управления.
4.
Данные о дате, времени выполнения операции сварки, сварном слое,
наплавленном валике сварного шва сохраняются в отдельном файле.
5.
Автоматизированные сварочные системы не требуют значительного
вмешательства оператора в ход сварочного процесса.
6.
Информация о типе и диаметре сварочной проволоки заносится в
программу.
7.
По окончании сварки на дисплее отображается вся наиболее важная
информация о ходе процесса сварки.
8.
Записанные параметры представляют собой ценную информацию о
процессе сварки.
9 Данные поступают в центральную вычислительную
систему для дальнейшей обработки.
10. Автоматизированная сварочная система обеспечивает
успешное осуществление сварочного процесса.

Vocabulary

simulation

моделирование; имитация,
  воспроизведение

word processing

электронная обработка
  текста

software

программное       или    математическое
           обеспечение, программные средства

storage

хранение

CD ROM

Compact Disk Read-Only
  Memory - компакт-диск

consumable

расходные материалы

fatigue

усталость (материала)

rod

электрод

reel of wire

моток проволоки

parent metals

основной металл

complementary

дополнительный, добавочный

traceability

отслеживаемость

NDT

nondestructive test
  испытание без разрушения образцов

distortion

деформация; коробление

tolerance

тех. допуск, допустимое
  отклонение

butt joint

стыковое соединение;
  соединение встык

fillet joint

шпоночное соединение

supervisor

инспектор

welding fume

сварочный дым, сварочные
  аэрозоли

extraction equipment

вытяжное (вентиляционное)
  оборудование

regulations

правила, устав; нормы;
  инструкция

copper wires

медные провода, проволока

to gain access

получать доступ

While-reading activity

Find the English equivalents in the text for the following
words and word combinations:

производство, частый пользователь, растущий рыночный
спрос, источник информации по сварке, выполнять простые вычисления, новейшие
программные технологии, заметный прогресс в производстве аппаратного
обеспечения, графическая система, набор правил, практический опыт, вопросы для
контроля знаний, видеоряд, круглосуточно, богатый источник информационных
технологий в области сварки, местный телефонный звонок, удобное средство связи,
набор протоколов, гипертекстовая ссылка, каталог веб-страниц, поисковая машина,
поиск технической информации, температура предварительного подогрева, иметь
доступ к персональному компьютеру, обучающие программы, скорость обмена
данными.

Reading

Text
4. IT in Welding and Cutting for the Welding  Engineer –
PC Programs and the Internet
The PC has now become an essential
tool in the work of the engineer for not only word processing but also
specialized tasks such as in design, simulation and performance
assessment. Within the manufacturing industry sector, most engineers have
access to a PC and the vast majority can be classed as frequent users. It is
not surprising, therefore, that in response to the growing market demand, a
wide range of computer programs have been written specifically for the
welding engineer. Whilst PC programs can be considered to be a mature source of
welding engineering IT, over the last year the Internet has emerged as a new
exciting source of welding related information.
 As the Internet is already widely used by many
welding engineers as a source of IT, guidelines are provided on how the vast
amount of information on welding engineering related topics can be accessed.
Welding engineering software for the PC
 The first IT packages written for the welding
engineer were for carrying out simple calculations such as the preheat
temperature level to avoid hydrogen cracking. However, as the PC became more
powerful (faster computing speeds and additional memory), their use was
extended to mass storage of information in databases such as for welding
procedures and welder qualification. More recently, software has incorporated
novel programming techniques, expert systems for knowledge based advisory type
software and multimedia systems for advisory and education and training
software. The main advantage of expert systems is that they are capable of
encapsulating expert knowledge, which may be largely subjective. Thus,
operation of an expert system differs from that of a conventional software
which progresses in a predetermined, step by step manner until a result is
obtained e.g. the preheat temperature or the output of a database.
Interrogation of a problem solving expert system will
produce an output, which is usually advice or an opinion as to the likely cause
of the problem and the recommendations to avoid the problem in the future.
 A noteworthy advance in computer hardware in recent
years has been the inclusion of a CD ROM player in the PC to provide a
multimedia capability. Multimedia combines scanned photographs, graphics,
animation, audio and video action with very fast processing and large databases
to provide very visual / interactive software.
T he CD ROM disk is crucial in that with a capacity
of 700MB can store over 250,000 pages of text, or up to 30 mins of video,
equivalent to 450 high density 3.5 in floppy disks.
Commercially
available software for the welding engineer
There is now a wide range of
powerful software available to the welding engineer which makes best use of the
computing, memory, knowledge based and/or multimedia facilities of the
PC. The IT programs produced as aids for the welding engineer can be
conveniently grouped into the following categories:  ► Repetitive
calculations; ► Storage of Information;
► Interpretation of Standards;
► Advisory;
► Simulation;
► Education and Training.
Many companies have written
software for in-house use but the examples described here have been
restricted to commercially available software.
Repetitive
Calculations
 This group was the first type of software written
specifically to help the welding engineer carry out routine or time consuming
calculations. Topics include the calculation of weld volume, consumable
requirements, cost of fabrication and design calculations for fatigue
service. WELDVOL is typical in that it will allow the user to calculate the
volume of weld metal to be deposited and from this information, the number of rods,
or reels of wire, to be purchased. The program can accommodate a range
of arc processes, joint types and parent metals.
Storage
of Information
XWELD is a welding procedure
management system. The system is a multi-user relational database and
has the following advantages over a paper based document control system:
► Integrated drawing system and graphics
library;
► Electronic distribution of procedures;
►Search functionality for all essential
variables of the procedure;
QMWELD is a complementary
program for management of fabrication information for ensuring that a
fabrication is completed on time and to an appropriate standard. The system
gives full traceability with NDT records.
Interpretation of Standards
FATIGUEWISE is based on BSI 7910 (formally PD 6493),
"Guidance on Methods for Assessing the Acceptability
of Flaws in Fusion Welded Structures". The software allows analysis of
structures, for safety critical applications, using either the fracture
procedures or the general fatigue procedures.
FATIGUEWISE is a typical software
for interpreting a standard which is a complex text procedure. A set of rules
derived from the standard are embedded in the software ensuring that
each time an assessment is made the standard is applied equally rigorously. As
most assessments require numerous calculations, the software will save
the user both time and costs especially when carrying out a sensitivity
or critical analysis by varying one of the input parameters.
The use of a friendly graphical
interface ensures that the user is only asked for information specific to
the current assessment.

Advisory

STAYING IN SHAPE is an
expert/multimedia system that provides practical advice and training on
how to overcome the problem of distortion caused by welding and
cutting operations. The information is based on expert knowledge and practical
experience. Multimedia (video, animations, audio, scanned photographs and
graphics) is used to facilitate the transfer of knowledge and learning.
The knowledge contained in the system includes:
► The different types of distortion and when
they occur;
► The factors in welding affecting distortion;
► Practical steps to reduce distortion;
► Precautions for specific welding and cutting
situations; ► Actions to correct distortion after welding.
The system also includes a series of
quiz type questions that will test the user's understanding of distortion.

Simulation

MAGSIM simulates the GMA welding
process calculating the weld shape and the thermal cycle at various points
along the weld (7). Graphics is used to display the cross section of the weld
and a 3-D view is used to visualize the simulation results; the calculated
thermal cycle and shape of the weld pool. The program can be used to
predict the weld quality for selected welding parameters with tolerances.
For butt and fillet joints in СMn and alloy steels, welding parameters
can be optimized for a specific task.
Education
and Training
WELDING FUME TUTOR is a CD ROM
based multimedia training course aimed at educating welders, supervisors
and welding engineers on the risks to health that could arise from inhalation
of welding fume. The program can also be used for training welders in fume
control techniques and use of extraction equipment. The information
contained is based on statutory regulations, expert knowledge and
practical experience. The program is interactive and combines video clips,
animated sequences, audio, scanned photographs and graphics.
Welding
engineering IT and the Internet
The Internet is unique in that it
contains a vast store of information which is readily available to engineers 24
hours a day. Its potential as a source of IT for welding engineers has yet to
be fully realized. In order to realize this potential, welding engineers must
have knowledge of:
► The Internet System;
► World Wide Web (WWW)
► Hardware Requirements
► Accessing and Searching the WWW
The
Internet System
The Internet is not a single
computer but a network of millions of computers linked by a telecommunication
system (copper wires, fibre optic cable and satellites). In
simple terms, the Internet can be considered a world-wide array of computer
networks linked by the telephone.
Information is stored on the
computers which are called "servers". Servers connected to each other
form "local networks" and the networks connected together form the
"inter-network" or Internet. The "client" is a computer
that allows user access to information services over the network.
Hardware
Requirements
The hardware requirements for accessing the Internet
are:
► PC
► Modem
► Internet service account
► Telephone line
The standard PC, costing
typically £1000, is suitable for connecting to the Internet but a modem
will be required; the modem is a device which allows a computer to transmit and
receive data via the telephone. Modems are increasingly being fitted to the PC as
a standard feature but it is recommended that for efficient communication, the
modem should be capable of a data exchange rate of at least 33.6kbs.
Electronic
post or e-mail
Electronic or e-mail is widely
used as the user can send and receive messages from anyone in the world who has
an Internet compatible e-mail address e.g. wlucas@twi.co.uk. The advantages of
the e-mail are that the messages cost no more than a local telephone call and
are stored on the recipient's computer until he is ready to look at his mail.
E-mail is a useful means of communication for engineers in that, in addition to
messages, documents, software and video images can be transmitted.
World
Wide Web (WWW)
The Internet is a physical network
on which the information travels but the "World Wide Web" or WWW is a
collection of protocols (rules) and standards used to access the information
available on the Internet. Each Web site has a unique address e.g. Esab
Europe's address is http://www.esab.se. Each document on the web site also has
its own address termed Uniform Resource Locator (URL). For example, http://www
twi.co.uk/bestprac is the URL of the document which contains technical
information from on best practice for welding "Job Knowledge for
Welders"; "http" tells the browser that it is a hypertext file
(Hyper Text Transfer Protocol), and http://www.twi. co.uk is the server on
which the web page is located.
The point-and-click user interface
is similar to more conventional windows based PC programs. The protocol tells
the user's computer how to display the information. The hypertext links allows
the user to browse through information held either on the same server or, more
importantly, on any other computer connected to the Internet. The WWW protocol
covers most types of information, including multimedia, and the method of
communication.
Accessing
and Searching the WWW
To enable a user to gain access
to the Internet an account is required with a "Service Provider".
When the user logs on to the Service Provider's server, the software will allow
the user to browse the Internet accessing and retrieving information from the
various servers/web sites.
To search for particular
information on the WWW, a "search engine" is used to produce an index
or a catalogue of web pages. Searching involves simply filling in a form with
words or phrases which describe the information you require. The search engine
will produce a list of Web pages which best match the query.
Welding
engineering IT on the WWW
The main use of the Internet by
engineers is to search for technical information, exchange technical data and
to purchase products. Most of the sites have hypertext links to many more sites
that contain related information on, for example, engineering, materials,
manufacturing and non destructive testing. TWI is typical of the organizations
offering technical information. The information available includes technical data
sheets, "best practice" guides, directory of suppliers, standards
information, abstracts of research projects.
The TWI Web site is accessed by
over 6000 users each month and approximately half of the users are from the
USA. The most requested pages relate to the technical information.
As advertising is freely practiced
on the WWW, most commercial companies have Web pages devoted to the advertising
and marketing of their products. The companies can make text, pictures, sounds
and video available on their Web pages using the hypertext mark-up language.
The ESAB WWW site (http://www.esab.se) contains the following PC programs
available from Business Area Consumables:
                ►
    WELDCOST     -     selection     of     welding     process     from
economic/productivity calculations;
► WELDOC - storage and retrieval of welding procedure
specifications;
► PREHEAT -calculation of preheat temperature;
► EQUIST -steel grades and their equivalents;
► STAR - stainless steel consumables;
► CONQUEST - range of steel
grades and their recommended consumables;
► THE
SCHAEFFLER-DELONG—WRC'92 analysis program is particularly useful to welding
engineers and metallurgists in that it can be used to select a suitable
consumable when welding dissimilar metals, predict the microstructure of the
resulting weld, warn about possible metallurgical risks on welding, build a
database of commonly used metals and their consumables.
A typical screen display may show
the composition of the resulting weld metal produced when welding 15 Mo 3 steel
to AISI316L stainless steel using the type OK 67.60 consumable. The diagram may
also contain a useful warning on the zones of weld metal compositions (nickel
and chromium equivalents) in which cracking is likely to occur.

After reading activity

Match the words from the left and the right columns:
1.   PC          A.
мультимедийные средства
2.   database  B.
многопользовательский
3.   expert system    C.
чувствительность
4.   step by step       D.
введенные параметры
5.   floppy disk       F.
волоконно-оптический кабель 6.multimedia  G. ПК
facilities
7.       in-house
use    H. практический совет
8.       weld
volume   I. объем сварочных работ
9.       multi-user
      J. внутреннее использование
10.   sensitivity       K.
критический
11.   critical   L.
экспертная система
12.input      M. пошаговый parameters.
13.
practical N. гибкий диск advice
14.
fibre  optic O. база данных
cable

Answer the following questions:

1.
How do engineers now use a PC?
2.
What are the two modern sources of welding related information?
3.
What were the first IT packages for the welding engineer used
for?
4.
What did faster computing speeds and additional memory make
possible to do in the field of welding?
5.
What is the difference between an expert system and conventional
software?
6.
What is multimedia?
7.
What is the storage capacity of a CD-ROM disk?
8.
How can the IT programs produced for the welding engineer be
conveniently  grouped?
9.
What can XWELD, QMWELD, FATIGUEWISE, FATIGUEWISE, STAYING IN
SHAPE, MAGSIM, WELDING FUME TUTOR do?
10.   Why is the Internet
a unique source of information to engineers?
11.   Are you an
Internet user?

Translate the following sentences from Russian into:

1.   Персональный
компьютер стал мощным инструментом в работе инженеров-сварщиков.
2.   Многие инженеры
сегодня имеют доступ к сети Интернет.
3.   Компьютерные
программы стали полноценным источником информации по сварке.
4.   Компьютер
позволяет хранить огромное количество информации в базах данных, выполнять
вычисления, с его помощью можно повышать квалификацию сварщика.
5.   Мультимедийные
программы содержат фотографии, графические и аудио-данные, анимацию.
6.   Специальные
программа позволяет выполнять расчет уровня температуры предварительного
подогрева во избежание образования трещин.
7.   С помощью
компьютерной программы можно рассчитать объем металла шва, количество
электродов, мотков проволоки.
8.   Интерактивные
программы обучения позволяют совершенствовать знания сварщиков по различным
аспектам, связанным с их профессиональной деятельностью.
9.   Все программы имеют
одинаковый интерфейс "указать и щёлкнуть".
10.
Большинство коммерческих компаний используют Интернет для
продвижения своей продукции.

Vocabulary

simulation

моделирование

word processing

1) электронная обработка текста 2) оперативное изготовление
  документов

IT

(information         technology) информационная технология

storage

хранение

database

база данных

filing cabinet

1) шкаф для хранения
  документов; 2) картотека, каталог

power generation

производство электроэнергии

bottleneck

узкое место

Reading

Text 5. Moving Weld
Management from the Desk to the Desktop

Part
1. Computers as Welding Expert Systems

Welding engineers have managed
welding procedures and welder performance qualifications using computers for
some years now. Engineers now readily access vital information - no more
searching through piles of paper. They can easily develop procedures and qualifications
through onscreen editing, get advance warning of expirations and produce a
professional-looking document in the end. Most fabricators now have local or
wide area networks so sharing information between key personnel is easier than
ever before. Computers can integrate management of procedures and
qualifications with production weld information and quality control (QC) data,
and so the benefits abound.
Computers have always been good at
storing, sorting and searching through large amounts of data, making them
suitable for pure database applications. Such applications have required
the user to know certain parameters, with little or no help from the software.
In welding, such systems have been used for managing welding procedures and
welder performance qualification. But, to date, most have had limited, if any,
expertise in welding.
The problem with building expertise
into software it is necessary to have a deep understanding of both software
development and the technology being computerized. In the welding industry,
this includes metallurgy, engineering, production, quality control and
standards. Standards are particularly important, as many aspects of fabrication
are specified via national and international standards, such as ASME IX, AWS
D1.1, EN 287/288 AND ISO 9000.
Software houses with no depth of
welding expertise or engineers with no depth of software development skills
both find it difficult to develop expert welding systems. It may be possible
for individual engineers to develop software, but long-term support is
difficult at best, and in most cases impossible. For storage of large amounts
of information, where considerable time is invested in entering the data,
long-term support is critical.
In addition, most existing software
systems in the fabrication industry are tools for individuals, not for large
parts of organizations, because, until recently, most organizations have simply
not had the infrastructure to allow information to be distributed
electronically. E-mail has helped change this. Electronic mail has driven most
fabricators to use local and wide area networks. These networks make it
possible to share welding procedures or welder approvals across a company via a
multi-user software system.
The management of welding procedures
is one of the most timeconsuming jobs of a welding engineer. Creating,
verifying and approving new procedures and checking, adapting and approving
existing ones take a ling time. Plus, searching for existing procedures for new
production welds requires expert skills. Consequently, this was one of the
first welding engineering tasks to be computerized.
The first welding procedure database
management systems were simply electronic filing cabinets. They used the
speed of data sorting that computers could offer to make searching for existing
procedures much quicker. Documents could be copied and edited to create new
documents quickly and easily. What they could not easily do, however, was help
the welding engineer create new procedures for new application.
The sources of such information are
wide and disparate. They comprise standards (welding and application),
consumable and base material handbooks, technical  literature; most difficult
of all to computerize is experience. To build all this into a computer program
would be impossible without a wide knowledge of the sources available.

After-reading activity

True or false?

1.   There are a lot
of computer programs for welding engineers.
2.   It is more
important to have a deep understanding of software development than the
technology being computerized.
3.   Most existing
software systems in the fabrication industry are tools for large companies.
3. The first database management systems could not
create new procedures for new application.

Part
2. Weldspec 4

Taking all this into account, The
Welding Institute (TWI), Cambridge, U.K., and C-spec, Pleasant Hill,
California, have collaborated to develop a new version of Weldspec. Weldspec 4
has been designed to help the welding engineer write and draft new welding
procedures while still giving the benefits of speed and editing of existing
procedures in Microsoft Windows®.
The software comes from many backgrounds, including
the following:
-   Worldwide
welding and application standards from such organizations as
ASME, AWS, European standards and API;
-   Industry
practice in developing, qualifying and using welding procedures;
-   Typical
interactions between customer, fabricator and inspector;
-   Welding
engineering and metallurgy;
-   Software
development and knowledge representation techniques.
Software so vitally based on
knowledge and recommendations from standards needs to be frequently updated;
indeed, ASME IX is updated annually. Because anything hard coded within
software is difficult to change, Weldspec's knowledge base is stored externally
to the main program so it can be modified.
Managing welder performance
qualifications (WPQs) is very similar to welding procedures: Both are designed
by standards. Variables that must be recorded, the extent of approval given by
a test and the destructive and nondestructive examination (NDE) regimes are
specified in national and international standards.
However, unlike welding procedures,
WPQs are only valid for a specified time without practice or additional
testing. Certificates expire, so the fast sorting capability of computers is
even more beneficial. By integrating another program called Welderqual 4 with
Weldspec 4 to share a database of welder details, WPQs can be created directly
from welding procedures.
An integrated software system such
as Welding Co-ordinator can help. Welding Co-ordinator is designed to be used
live to manage fabrication as it is progressing. It is usually based around an
electronic weld map, weld data sheet or weld schedule, into which data are entered
as welds are designed, engineered, welded and tested. The weld map would also
usually have some space for approval, either weld by weld, or once a project or
structure has been completed. The Figure below shows a detail of a typical weld
map for a fabricator in the power generation industry.
Data are usually entered into the
system from four functions, as follows:
 At the design stage, where information such as the
weld ID number and other design parameters (material type, thickness, joint
type, etc.) are entered.
 At welding engineering, where a procedure is
assigned. It may also be possible to identify suitable welders or classes of
welders qualified to make the weld, although this is more likely to be done at
the production stage. At production, where the completion of a weld is
registered (usually by entering the date) and visual inspection carried out and
approved.
 At quality control, where acceptance of the weld is
registered. This may be simply by typing test report numbers into the system,
or it may be done with live links to electronic NDE reports.
The system also gives instant
progress reporting. Anyone with access to the system can see how fabrication is
progressing. This may be simply by looking at the weld data sheet on screen or
by explicitly programmed progress reports. These can identify bottlenecks
(by, for example, comparing the number of welds competed with the number of
weld radiographed), or help to produce reports for stage payments in large
projects.
It also provides automatic
assignment of welding procedures and welder. If enough information is supplied
at the design stage, the system searches through a database of procedures for
suitable welding procedure specifications (WPSs). This may be a single WPS of a
number from which to choose from, with a click of a mouse button. Having chosen
a suitable WPS, the system searches through WPQs for qualified welders. If
necessary, the system can list welders in order of their certificate expiration
dates; with those due to expire soonest at the top of the list; so maximum
benefit can be made of extending their qualification.
The system can also produce reports
on repair rates per welder (to identify training requirements), by procedure
(to highlight defect-prone procedures) or by any other measure,
providing the relevant data are recorded.
It also automatically generates
document packs on completion of a project. A very time-consuming task manually,
it's again ideally suited for computerization. With the click of a button, the
system can print the weld maps for a project, along with all the WPSs used
(with backup procedure qualification records (PQRs) if necessary and all the
WPQs, which are updated automatically based on satisfactory production welds.
In addition, if NDE specifications have been used to report testing, the system
can print relevant NDE reports as well. This information can also be archived on
CD.
It can also instantly trace
production welds to the information backing them up. If the inspector wants to
see a WPS that was used on a weld, or proof that the welder was suitably
qualified, this can be done with the click of a button. This can be especially
useful while inspection a structure after a number of years of service. If a
defect is found, the engineer can access the original WPS, for repair purposes,
or the NDE report, to see if evidence of the defect was present at testing.

Answer the following questions:

1.     What
can Weldspec 4 do?
2.     What
are the main sources from which Weldspec 4 originated?
3.     How
can Weldspec 4 be updated?
4.     How
is data entered into the system?
5.     In
what ways can the system produce reports?
6.     What
time-consuming tasks can Weldspec 4 perform with a click of a button?
7.     What
is the difference of a usual welding software from an expert system?
8.     What,
in your opinion, computers will never be able to do in welding?
Writing

Imagine
you are given a task by the head of a big welding company to make a research
and decide whether it’s worth while introducing computers into the production
process. Write a report to your boss mentioning the following points:
-     What
kind of software is available for welding engineers?
-     How
can welders get access to welding related information?
-     How
can computers improve the work of welders?
-     What
welding procedures can be best computerized?

PART
6. ADVANCED TECHNOLOGIES AND THE FUTURE OF WELDING

Lead-in

Think of the answers for the following questions:
1.   Why can welding
be necessary on board of a spaceship?
2.   What kinds of
welding methods, in your opinion, are good for use in space?
3.   Why is welding
in space such a difficult task?

Vocabulary

instrumentation

оснащение
  инструментами, приборами, аппаратурой, комплект инструментов, аппаратура

reflecting shield

отражающий экран

preventive maintenance

профилактическое обслуживание

arc discharge

дуговой электрический
  разряд

globular

шаровидный, сферический,
  сфероидальный, шарообразный

retrofitting

подгонка, настройка

deposition

осаждение

While reading activity

Match the words in italic from the text with their
Russian equivalents below: Вакуумная камера, летательный аппарат, источник
тепла, космический корабль, открытый космос, солнечная энергия, компьютерное
моделирование, ручной инструмент, банк данных, улучшенный материал (материал с
улучшенными свойствами).
Reading

Text 1. Space-Age
Welding: The Past, Present and Future
of Aerospace Join Processes
By B.E.
Paton
April 10, 2003
On Oct. 16, 1969, astronauts
performed the world's first welding and cutting experiment in a depressurized
compartment. In flight aboard the
Soyuz 6 spaceship, they tested three welding processes
with a semiautomatic Vulkan   unit    (see   Figure         below):       consumable
electrode arc in vacuum, low-pressure plasma, and electron beam welding. They
studied how to weld aluminum and titanium alloys and stainless steel. They
verified the possibility of thermal-cutting these materials and investigated
the behavior of molten metal and features of its solidification.
This experiment convinced experts
that they could use automatic welding to produce permanent, tight joints in
space. They expanded this work with a
Two         cosmonauts     conduct        series
of investigations conducted under short-time
preflight training of a crew
with Vulkan hardware in October  microgravity conditions in flying
laboratories and
1969                                              space
simulation test chambers. In 1973 NASA
experts conducted a flight experiment with electron
beam cutting, brazing, and welding in the Skylab
orbital station.
Space welding technologies have
advanced since then. In-space repair and construction of space facilities and
their equipment and instrumentation were defined in the 1980s. Another
major area identified was producing advanced materials in space with new
or improved properties using different heat sources.
Over the years scientists and
specialists had to address construction of various experimental space
vehicles, namely, orbital and interplanetary stations, radio telescopes,
antennas, reflecting shields, and helio power generation systems
- in outer space.
In addition to the original problems
of assembly and erection in outer space, as well as their view of how
long these vehicles would be used and increases in the vehicles' weight and
dimensions, specialists focused more attention on preventive maintenance
and repairs.

Initial
Welding Experiments
The first welding experiments
conducted in space demonstrated that arc welding processes, which were widely
accepted on earth and at first were promising, had unfavorable characteristics
in space, such as unstable, weakly constricted arc discharge; unstable globular
transfer; and increased weld porosity.
During experimental retrofitting in
simulation facilities-chiefly in space simulation chambers placed in flying
laboratories-the difficulties related to these characteristics were
successfully resolved. Specialized welding equipment and techniques also were
developed for this purpose, and the required welding consumables often were
selected from those used in the aerospace industry.
However, it was clear to space
system developers that almost all maintenance and repair of long-term flying
vehicles - for which neither the scope of work needed nor the components to
be repaired and restored are known in advance-had to be performed manually with
only partial mechanization. This increased specialists' interest in studying
the possibility of manual welding in space, which led them to consider which of
the existing welding processes to use.
Welding processes such as electron
beam, consumable and nonconsumable electrode arc in vacuum, flash-butt, hollow
cathode, and helio welding were tested in vacuum chambers and in flying
laboratories at different stages of experimental studies in the 1970s and
1980s.
Technology
and material versatility and minimal power consumption ultimately were deciding
factors that led them to choose the electron beam process.   This   process          allowed
technicians to perform operations that could be required to produce a permanent
joint in open space: heating, brazing, welding, cutting, and coating deposition.

But selecting this process didn't
solve all the problems. As investigations progressed, the number of problems,
technical and
Cosmonauts test an electron
beam hand tool at the                  psychological,      increased.      An

Salyut
7 orbital station. opinion
existed that this process, which involves high-accelerating voltage, the
possibility of X-ray radiation from the weld pool, and manipulation of a
sharply focused electron beam, couldn't be done manually.
A series of experiments in a ground-based, manned
space simulation chamber enabled the engineers to solve the key technological
and hardware issues and develop a flight sample of an onboard electron beam hand
tool. In 1984 and 1986 this tool was successfully tried out on the outer
surface of the Salyut 7 orbital complex (see Figure above).
Based on new engineering systems
that corrected technical parameters and suggestions from the test engineers and
crews during experiments in the Salyut station, engineers developed a new
electron beam hand tool in the 1990s. The tool passed lengthy testing at NASA's
Marshall Space Flight Center and Johnson Space Center. During testing in a
flying laboratory and at zero buoyancy, as well as in a manned space simulation
test chamber in Russia, the developers were able to solve almost all the
technical and procedural problems with the tool.

Further
Aerospace Welding Exploration
Almost 40 years'
experience of technology developments and their application leads to the
conclusion that in this new century, major, complicated space work will have to
be addressed. Welding technologies will be of tremendous importance.
Such technologies are partially in place, but further space
exploration will require developing new welding, cutting, brazing, and coating
processes. New exotic materials will be introduced in the new century, and
their processing and joining will require completely new technologies.
A number of space operations can be
performed remotely, using robots and manipulators.
Welding in space might become widely accepted only if
completely new methods of nondestructive testing and diagnosing welded
structures can be developed. This can be supported by data banks that
allow automatic selection of the process and computer simulation.
Laser applications in space, including such hybrid
processes as laser-plasma and laser-arc welding, offer promise, especially
diode lasers. Friction welding and resistance seam-roller welding also are of
interest.
Advanced space systems will continue
to be developed both on the ground and in orbit. New welding and related
processes and technologies will have an important role in those developments.

B.E. Paton is director of the E.O.
Paton Electric Welding Institute, Kiev, Ukraine.The E.O. Paton Electric Welding
Institute is a multidisciplinary research institute that realizes fundamental
and applied research works and develops technologies, materials, equipment and
control systems, rational welded structures and weldments, and methods and
equipment for diagnostics and nondestructive quality control. Paton also is
president of the National Academy of Sciences of Ukraine.

Speaking

True or false?

1.   The world's
first welding and cutting experiment was carried out in the outer space.
2.   Thermal-cutting
of aluminium, titanium alloys and stainless steel is impossible in space.
3.   Only automatic
welding is of importance for aerospace.
4.   A flight sample
of an onboard electron beam hand tool was produced as a result of series of
experiments.
5.   Space welding
is used for maintenance and repair purposes.

Translate the following sentences into English:

1.   На борту
космического корабля исследователи изучали поведение расплавленного металла и
особенности его кристаллизации в условиях кратковременной микрогравитации.
2.   Технологии
космической сварки шагнули далеко вперед.
3.   Одна из задач,
решаемых с помощью сварки в открытом космосе, - профилактическое обслуживание и
ремонт оборудования космического корабля.
4.   Разнообразие
используемых материалов и невысокая энергоемкость оборудования являются
решающими факторами, обусловливающими возможность использования сварки в
открытом космическом пространстве.
5.   Дальнейшее
освоение космического пространства потребует усовершенствования практически
всех видов сварочных технологий, а также резания, пайки и нанесения покрытий.
6.   Специфика
используемого на космических кораблях оборудования обусловливает необходимость
использования прежде всего ручной сварки при частичной автоматизации процесса.
7.   Электроннолучевой
ручной сварочный аппарат прошел успешные испытания на орбитальном комплексе в
условиях открытого космоса. 8. Использование новейших материалов в следующем
столетии потребует разработки совершенно новых технологий получения неразъемных
соединений.

The title of the text under review is “The past,
present and future of aerospace join processes”. Look through the text again
and say which event relates to:

a)   the past
b)  the present
c)   the future

The key words from the table below will help you

The past

The present

The future

1969,
  1973, 1980s, 1990s, verifying the possibility of thermalcutting and welding
  in space

testing
  in a flying laboratory, the electron beam process, manned space simulation
  chamber, solving almost all the technical and procedural problems

completely new methods
  of nondestructive testing and diagnosing welded structures,  advanced space
  systems development, new
exotic materials

Vocabulary

down-hand welding

сварка в нижнем положении

celestial body

небесное тело

bend load

нагрузка на изгиб

welding sequence

последовательность сварки; порядок
  наложения швов

tensile load

растягивающая нагрузка

pressure load

сжимающая нагрузка, усилие сжатия

root pass

корневой шов, проход, сварка корневого шва

tolerance

допуск

manual welding

ручная сварка

post-polishing

последующее полирование

tack weld

прихваточный сварной шов, прихватка

X-ray testing
  (qualification)

рентгеновская дефектоскопия

high duty

жесткий режим

clamping fixture

прижимное устройство

ASME

American Society of
  Mechanical Engineers Американское общество инженеровмехаников

DIN

нем. Deutsche
  Industrie-Normen Немецкие промышленные стандарты

ID

inside dimensions
  внутренние размеры

U-shape (bend)

двойной изгиб; U-образное
  колено, двойное колено

grinding

шлифовка

weld seam

сварной шов

filler wire

присадочная проволока

saw blade

1) пильное полотно; пильная
  лента 2) ленточная пила; дисковая пила 3) режущий диск

bevelling

1) отточка косая 2) угол
  фаски 3) фацетирование

performance capabilities

1)
  возможности 2) рабочие характеристики

work piece

Reading

обрабатываемая деталь

Text 2. What Is Orbital
Welding

The term Orbital-Welding is based on
the Latin word ORBIS = circle. This has been adopted primarily by aerospace and
used in terms of Orbit (noun) or Orbital (adjective) for the trajectory of a
man-made or natural satellite or around a celestial body. The combination
Orbital Welding specifies a process by which an arc travels
circumferentially around a work piece (usually a tube or pipe). The concept
Orbital Welding is basically a loosely defined term that is usually used
for processes only, where the arc is travels at least 360 degrees around the
work piece without interruption. Consequently, processes, which interrupt the
full 360-weld sequence such as for better puddle control (often used for
MIG/MAG welding, using the downhand welding sequence in 2 half-circles), can
not truly be called orbital welding.
Possibilities
and Limitations
From welding terminology Orbital
Welding belongs to the category semi-mechanized (TIG-) welding. Because
of the need for good control of the weld puddle, the Orbital-Welding process is
only practiced with the TIG process and relevant rules like selection of gases,
cleanness, weldability of specific materials and consequential mechanical
strength specifications such as tensile and bend loading, are very important.
Orbital-welding is presently used
whenever the quality of the weld joint has the highest priority. These demands
are not only limited to mechanical strength and X-ray qualification, but also
to the important aspects of the aesthetics of the weld seam. For any users a
uniform, flat and smooth root-pass is the main reason for using this process.
Consequently, it is favoured in the following areas: chemical industry,
pharmaceutical industry, bio-technology, high-purity water systems,
semiconductor industry, aircraft- and aerospace industry. Moreover, because of
the weld joint's uniform outside shape and almost complete absence of need for
any post-polishing, Orbital-welding is even used for bends on door-handles,
hand-guards, or in dead foot-elements for champagne-glasses! Interested
applicants for this technology should certainly note that they have to confirm
a couple of indispensable premises.
The following presents the basic
rules for this process, valid for all manufacturers and systems.
Even knowing that some competitors are announcing
features, which would potentially violate the basic physical laws of nature and
knowledge, moreover, making promises and statements which are at least detected
as impossible to meet when the welding system must work under high dutycycle
production conditions. Indiscriminate and exactly defined dimensions
with tolerances must be thorough and complete. The much liked standpoint, that
the welded tubes and pipes are in accordance to DIN or ASME standards are not
acceptable criteria. These qualifications only define tolerances in percentage
to the wall thickness relating to pressure loading and not to weldability using
the Orbital-Welding-Process.
For the Orbital-Welding-Process
absolute tolerance values are necessary, and furthermore, the more complicated
the application, the tighter the tolerances must be. This means, that for an
easy application like welding a stainless steel tube of 53 x 1,5 mm, a
tolerance in alignment of about 0,5 mm (about 30% of the wall thickness) can be
compensated, but for much more critical applications like welding a
carbon-steel pipe of 114,3 x 3,6 mm, the same percentage can result in
unacceptable weld quality. Therefore, the question of acceptable tolerances
should be researched and defined for each application individually.
That Orbital-Welding can be used
successfully and economically is proven by the constantly increasing number of
users. Field experience has shown that Orbital-welding can be justified based
upon economic reasons alone, where the welds can be done in squared-butt no-gap
preparation utilizing a single pass. With advanced digital welding systems this
is possible up to a wall-thickness of 4 mm, and with welding systems with lower
performance capabilities (limited levels, no pulse-synchronized
cold-wirefeeding), up to 3 mm.
Joint preparation is simple but
requires high quality with an exact 90\'b0 angle to the tube/pipe axis; a high
quality saw cut is usually enough. Of course, the joints should be deburred and
cleaned out of corrosion, oil, tinder, etc. With appropriate quality-demands,
this should be even obvious for manual welds! The tube joints will be then fit
together without any visible gap. This can be done with small autogenous
tack-welds or with internal or external clamping fixtures. For larger wall-thickness
it is necessary to bevel the weld-joints, far as possible in a U-shape. Since a
very precise and uniform root pass is important, a weld joint is prepared with
an. I.D. related and fixed bevelling-machine. Manual grinding or the use of
bevelling saw blades is not precise enough for repeatable welding results.
Because an Orbital-Welding job usually requires a lot in time and money, the
Orbitalmulti-pass-welding is not used very often and only where it is strictly
recommended on quality reasons. A good qualified manual welder will, in most
cases, be faster than an Orbital-welding-system. Additionally, an
Orbital-system for multi-pass welds will be much more expensive and even more
complicated than a system without this option.
Visual inspections of the weld-seam
clone can never be sufficient as the sole criterion. Other quality controls,
such as, corrosion, consistency, mechanical strength must also be considered.
Also, allowed tolerances in contents of alloys on specific materials, such as
sulphur content, can result in significantly different welding results, even
when the material code is the same. Usually, you can expect that stainless
steel materials up to 3 mm wallthickness can be done without filler-wire. For
higher wall-thickness applications, you have to decide on a case-by-case basis.
In some eventualities even carbon steel can be done without filler-material,
although it's even recommended on the thinner wall-thickness to use filler-wire
in any way.

After reading activity

Find the English equivalents in the text for the following
word combinations:

противоречить законам физики,  обращаться  вокруг
обрабатываемой детали, иметь первостепенное значение, контроль сварочной ванны,
красивый внешний вид сварного шва, гладкий и ровный проход при заварке корня
шва, шлифовка вручную, приемлемый допуск, недопустимое качество сварки,
квалифицированный сварщик, содержание серы, механическая прочность,
искусственный спутник, система высокой очистки воды, обязательное условие.

Characterize orbital welding by filling in the right side
of the following table:

Parameter

Description

Model:
Principle of the process

An arc travels
  circumferentially around a work piece (usually a tube or pipe).

Category

Application areas

Limitations

Speaking

True or false?

1.   Orbital Welding
is a process, where the arc travels at least 360 degrees around the work
piece with some interruptions.
2.   MIG/MAG
welding, using the down-hand welding sequence in 2 halfcircles, refers to
orbital welding.
3.   Puddle control
is very important for Orbital welding.
4.   The number of
Orbit Welding users stays the same for a long period of time.
5.   Aerospace
industry is the only area of Orbital Welding application.
6.   Joint
preparation is not necessary.
7.   Orbital-welding-system
is very fast and cheap.
8.   Filler-wire is
used for all wall thickness applications.

Describe Orbital welding by completing the following
sentences:

1. The term Orbital comes from the Latin word ORBIS
and means … . 2. The Orbital Welding is a process in which an arc
travels … . 3. By category it belongs to … . 4. It is practiced  only with … .
5.Orbital-welding is presently used in such areas as … . 6. It is used to
produce …  . 7. The basic rules for this process are … . 8. Absolute tolerances
in Orbital-Welding Process are important because … . 9. Wall-thickness of 4 mm
is possible … . 10. Joint preparation includes … . 11.
Orbital-multi-pass-welding is rather expensive and its use is only justified
when … . 12. Filler-wire is necessary to use only …  .

Additional
Reading

Text 3. Welding Forges
into the Future

Answers from a survey of industry leaders give
valuable feeedback on the state of welding for the year 2000 and beyond.

By Andrew Cullision and Mary Ruth Johnson

The pulse of the welding community
beats strongly heading into the 21st century and overall projections for the
future are generally optimistic, but a few gray clouds roam the horizon. Those
sentiments were expressed by respondents to a recent Welding Journal survey. To
get a firm feel for that pulse of present and future conditions in the world of
welding, the Editors queried AWS Sustaining Member companies, which include
producers of a variety of welded products, providers of research and design
services and manufacturers of welding equipment, consumables and accessories.
The Editors would like to thank all
those who took the time to put down their thoughts and ideas on paper. The
responses were diverse, direct and, most of all, very interesting. Those
questions and a summary of their answers are presented below.
-
Do you believe welding will be used more or less in the
next decade? If more, where do you see the growth? If less, why do you believe
so?
The majority of respondents feel
welding is here to stay and will be used more in the future, although many
qualified their answers, and there were a few dissenting voices as well. Steve
Sumner, manager marketing product development, Lincoln Electric Co., replied
positively, "Welding will continue to be used more in the future because
it has proven to be a productive and cost-effective way to join metals."
He went on to speculate that "the consumer welding market will continue to
provide opportunities for growth," with home improvement and the retail
infrastructure to support it becoming a "burgeoning market." One
respondent felt that for costcompetitive reasons industry will continue to
replace mechanical joining with semiautomatic and automatic joining processes,
giving a definite boost to welding. David Landon, corporate welding engineer,
Vermeer Manufacturing Co., said, "More, because welding is the most
effective way to join materials for structural integrity. Growth will be in
alternative materials such as plastics, composites and new alloys." Phil
Plotica, senior V.P., sales and marketing North America, ESAB Welding and
Cutting Products, replied, "Overall, I expect welding growth will keep
pace with growth in the GNP. Some specialized segments, such as aluminum, will
grow faster than others, while the continuing developments in nonmetallic
materials will slow some segments."
The feeling that growth will be in
specialized areas was repeated often. Areas that were mentioned included
welding automation, GTA welding because of the increasing need for accuracy and
precision in welding new metals; GMA welding with mixed gas shielding; sheet
metal industry; construction industry; infrastructure repair; transportation
industry; marine structures; aerospace; and automotive, especially its use of
aluminum alloys.  Some feel the growth will primarily be in countries with
emerging economies, while the growth in the United States will be relatively
stagnant. Terry O'Connell, V.P. sales and marketing, Genesis Systems Group,
commented, "The U.S. welding market is flat to declining. Growth is
expected in Mexico and other developing countries. Labor shortages in the U.S.
will contribute to a steady growth in the robotic welding market." Joe
Scott, president, Devasco International, Inc., echoed the sentiment, "Less
in the U.S. with expectations of a slight decline in the economy, as well as
the continuing transition to a service/information economy. Outside the U.S.,
growth is expected as economic stability returns to troubled regions and their
need for infrastructure grows."
The perspective of some, though, is
that welding will be used less in the future. Chris Anderson, product manager,
Motoman, Inc., opined, "There will be less welding in the next decade. The
number of welded products will remain the same, but designs will be more
efficient to minimize the amount of welding."

-
Which welding process (es) will see an increase in use and
which will see a decrease in use during the next decade?
There was much speculation as to
which processes would see more use in the future, but almost unanimously the
process chosen for decline was shielded metal arc welding (SMAW). A very few
speculated a decline in the use of gas metal arc (GMAW) and gas tungsten arc
welding (GTAW).
A significant group felt the
continuous wire processes (FCAW, GMAW) would experience the most use. The GTAW
process was the next most mentioned. One of the reasons stated for its increase
was "the need for high-quality work on thin materials."
Don Connell, welding engineer,
Detroit Edison, stated, "Any process that can be automated will
increase." Landon also had the same perspective, "GMAW will increase
along with automation." But he also speculated, "Low-fume generating
processes will increase." The concept of increased use of automation at
the expense of semiautomatic operation was voiced throughout.
The laser beam welding process was
mentioned for future growth, and the specialized process friction stir welding
was also targeted for expanded use. Other processes mentioned for increased use
were resistance welding, plasma arc welding and capacitor discharge welding.

-
Do you foresee a shortage of skilled welders in your area of
business during 1999; in the next decade?
Without question, the majority of
replies indicated there is a shortage now and there will be a shortage in the
future. The breakdown was 72% consider the situation problematic now and for
the long term, 14% did not see a shortage and the remaining 14% either see no
shortage now, but expect one in the future or see a shortage for 1999, but not
for the future.
John Emmerson, president, Magnatech
Ltd. Partnership, made a typical comment for those who see a far reaching
problem, "There is a shortage of skilled welders everywhere in the world,
and it is only getting worse as each year passes. Despite the fact that welding
is used in virtually every industry, it seems virtually ignored as a
manufacturing science. Connecticut [the state of location for Magnatech], for
example, dropped its Vo-Tech welding classes in 1997. In addition, population
dynamics in recent years in the U.S., Europe and Japan indicate that the next
decade will see a much smaller number of young people entering the work force.
This, by itself, will result in fewer welders."
ESAB's Plotica had a similar take on
the situation, "There is a shortage of skilled welders now in most major
market areas, and this shortage will worsen unless substantial programs are
implemented to promote welding as an attractive career choice for young
people."
Landon of Vermeer Manufacturing stated, "We have
had a shortage for the past five years. I see no turnaround, and we will not
see a turnaround until the establishment acknowledges welding as a viable
career path. To meet our immediate demands, the company has developed its own
welder training program. The company is also involved in proactive programs
that make instructors at high schools and area colleges aware of welding as a
viable career."
Connell of Detroit Edison, does not
see an immediate problem, as he encouragingly stated, "There is a renewed
interest in the boilermaker's welding program, bringing in a good influx of
people. I don't foresee a shortage in 1999." Another respondent took a
contrary view, noting a shortage of skilled welders in 1999, but projecting a
leveling of demand in the next decade.
J Julio Villafuerte, director research and
development, Tregaskiss, had a slightly different perspective. "The need
for plain skill welders will decrease slightly with the slowdown of manual
welding. However, the need for welding engineers will increase dramatically as
welding automation becomes more prominent."

-
Where do you see the use of welding automation heading in your industry?
If there is any one thing to bank on
for the future, it is the increased use of automation in welding operations.
There was an overwhelming affirmative from our respondents on this point,
although it was not completely universal. The perspective of those few who did
not see increased use might be expressing an influence from their particular
industry. A structural steel fabricator mentioned the difficulty in automating
for weldments that do not have a high degree of repetitiveness and variations
in fitup and joint geometry. Another individual felt automation will not
replace welding equipment for manual operations if the equipment is developed to
be fast, safe and economical.
But by far the majority feel the
same as Magnetech's Emmerson, who stated, "We see more and more companies
of all sizes automating applications that were being done manually. Many are
exploring their first use of automation, and the declining number of skilled
welders will continue this trend." The lack of, or declining numbers of,
skilled welders was frequently mentioned as reason for the growth of
automation.
Philip Winslow, V.P. sales and
marketing, Hypertherm, Inc., noted another often stated reason, "Usage
will increase, primarily because of the consistency it gives to welding and
cutting operations, especially with CNC (computer numerical control) and
robotically controlled processes." Lincoln's Sumner was emphatic in his
assessment, "Automation is the single most important growth sector in the
welding industry. The drive for higher productivity and reduced costs will keep
automation at the forefront." Other reasons for the increasing use of
automation included safety and the effort to remove the welder from tiring,
repetitive conditions and long-term exposure to fumes.
Chip Cable, president,
Bug-O-Systems, isolated shipbuilding and the trucking and railroad industries
as areas that will experience growth in automation. A fabricator of offshore
steel structures has targeted automation for heavy tubular splices, plate
girders and process piping. Small companies and job shops are anticipated to at
least try robotics and CNC equipment.

-
What are the strengths of the welding industry? What are its
weaknesses?
Although our respondents listed
plenty of strengths and weaknesses for the welding industry, Plotica of ESAB,
perhaps best summed up the two most commonly held opinions. Regarding the
industry's strengths, he said, "We are a well-established, mature industry,
with a solid track record in technology and process advancements." And as
to its weaknesses, "We are not attracting enough young people into welding
careers," Plotica said. "Welding is still perceived by many as a
crude and dirty process."
While many saw the industry's
maturity - the reputation of welded components for being reliable and
economical, the industry's commitment to research and development and the
dedication of its work force - as signs of its strength, nearly as many others
saw it as a weakness. They believe the industry is set in its ways and slow to
change. According to one respondent, the industry's strength is that the people
involved in it are "slow to change, with a show me attitude." On the
other side of the coin, he said, "Its weakness is that they're slow to
change even after you show them." And while a number of respondents lauded
the industry's commitment to research and development, others claimed it's too
esoteric and takes too long to transfer from the academic level to the factory
floor.
Thomas C. Conard, president of
Alexander Binzel Corp., had another take on the industry's weak spots. He noted
welding is not a separate industry in and of itself but instead makes up part
of many other industries. The implication here might be that welding lacks a
clear-cut image and direction.

-
What business improvements during the next ten years would be
in your company's best interests?
As might be expected, there were
nearly as many different answers to this question as there were respondents.
These ranged from broad-based desires, such as a wish for growth in any field
that uses metallic materials, to a more narrow focus, such as wanting increased
use of electronic commerce and supply chain management. Better trained workers,
improved communication techniques, designing for manufacturability and
lessening the time it takes to get new products to market were all mentioned as
in companies' best interests. Several persons called for increased automation.

Several respondents said a change in
the government's role with regard to their operations would improve their
businesses. This could occur either through less government involvement or
through such things as restriction of imports, "reasonable environmental
legislation that does not drive up the cost of doing business," tort
reform in product liability and lower taxes.
"We spend a tremendous percentage of our income
toward research and development," explained Emmerson of Magnatech.
"The continuation of tax credits for small company R&D would be
beneficial. We note that several of the Canadian provinces are very aggressive
in nurturing technical innovation and the growth of small companies, and allow
virtually all R&D expenditures to be written off against income. I believe there
would be an explosion of new development and company growth if any of the state
governments undertook similar tax credit programs."

-
What has to be done in the future to keep the welding industry
healthy?
More than 50% of the respondents
believe improving the image of welding so top students will be drawn to the
industry and bettering training methods for welders and welding engineers are
the keys to welding's future.
We need to "totally revise the
public education system in the United States to acknowledge the trades as an
acceptable alternative for students," according to Connell of Detroit
Edison. This echoed the opinion of David Yapp, team leader, arc welding and
automation, Edison Welding Institute, who said there needs to be "a
radical change in education at all levels." He added, however, "This
is not likely to happen without strong leadership and commitment."
In fact, respondents touched on a
variety of aspects related to training - all with an eye toward welding's
future. In the opinion of Jackie Morris, quality manager at Bender Shipbuilding
& Repair Co., Inc., the level of cooperation between manufacturers and
schools must improve so that manufacturers' needs are met. Genesis' O'Connell
said the welding industry needs to do two things: "Enhance ease of use
through technical training and technology advancement," and
"concentrate on making welding the low cost, best performance choice for
material joining." For the question regarding welding's weaknesses,
Anderson stated it's "often not scientifically applied, which leads to
overdesigned weldments and process parameters that are not optimized."
Anderson touched on the topic again in answer to the above question, when he
said, we must "continue to educate students on the basics of the process
and how to implement it. (We must) teach the economics of welding to designers
so they understand the costs of a weld."
Respondents also mentioned improved
salaries for welders, staying ahead of environmental and health issues and more
practical research and development as ways the welding industry can help itself
stay healthy.

-
Are you optimistic or pessimistic about the future of your particular
industry?
Overwhelmingly, the respondents to
the survey said they were optimistic about the future of their industries. In
fact, 92% of respondents indicated they are at least guardedly optimistic about
the future. One respondent summed up his reasons this way: "Metallics will
be around for a long time and they will need to be joined."
Much the same opinion was held by
Lincoln's Sumner. "I am optimistic," he said. "Even though we
are mainly tied to the steel industry, which has seen a slight decline, we have
much more to learn about welding and furthering the process of joining metals.
I believe products and services that the welding industry provides will
continue to be in demand worldwide."
Paul D. Cunningham, president of
Weldsale, indicated he was optimistic because "gains in technology via
software and the Internet will help increase productivity in the U.S.A."
Winslow of Hypertherm foresees a bright future: "If we improve our
understanding of our worldwide customers' needs, we have a road map to
unrestricted growth."
However, some respondents, such as
Thomas A. Ferri, a welding process specialist with Airgas, expressed optimism
while adding a word of caution. Ferri said he was "optimistic so long as
we know our industry needs some changes." Morris of Bender said he was
"optimistic in that shipbuilding and repair is a sound profession with an
increasing market; pessimistic in that environmental restraints are greatly
increasing operating costs and decreasing profit margins. There is a need for
better dialog between industry and the private sector."

-
During the 1990s, the trend has been for company buyouts and mergers. Do you
see that trend continuing and is it healthy for your industry?
Not all of the respondents answered
both parts of the above question. From the answers received, three times as
many respondents believed the trend for company buyouts and mergers will
continue. Several stated, however, that the pace will slow from that of the
early 1990s. Besides slowing down, "a certain degree of counteraction, i.e.,
divestitures, may also begin to take place," according to Plotica.
"For the most part, the buyouts and mergers have been healthy by providing
resources and growth opportunities to small- to medium-sized companies that
would have not been possible otherwise." With regard to it being a
positive trend, most respondents agreed with Plotica. In fact, three times as
many respondents stated it is a healthy trend as opposed to those who believe
it is not good for industry. "Every buyout and merger has victims and
winners," one respondent said. "It also creates opportunities.
Ultimately the industry does become more efficient, which is healthy."
It appeared, however, that
respondents who work for welding equipment and consumables manufacturers rather
than end users were more likely to consider it a negative trend. "The
welding industry is getting smaller every year," one respondent wrote.
Another said, "Who's left to buy without creating an antitrust monopoly
issue?"
Langdon of Vermeer presented a case
for both sides. On the positive side, Langdon said, "Larger companies have
more resources for research and development. Also, mergers present a larger
buying power and, in some cases, allegiances to manufacturers. Some of the
buyouts that we are seeing, especially in the equipment rental industry, could
be a real boon to our company." On the negative side, "less
competition," he said.
While stating that "company
buyouts and mergers can have very positive benefits for the industry and the
consumer," Emmerson also put in a word of caution. "To use an
overworked phrase," he said, "if there are no 'synergies' between a
group of companies beyond the fact that they are associated with the welding
industry, the risk is that the performance of small, newly acquired companies
will suffer as their original owners bail out and no strong management fills
the void."
Sumner voiced the opinion of several
respondents when he said, "I believe that these consolidations have
fostered an environment that is healthy for the industry with more focused
competition between larger manufacturers. This competition is good for all of
us to help move the industry forward and provide customer solutions."

Conclusion

Since time machines still exist only
in the stories of H. G. Wells and other works of science fiction, no one can
tell us exactly how welding will fare in the 21st century. However, the people
who responded to the Welding Journal survey represent a cross section of
fabricators of welded products and producers of welding equipment and related
products. Together they offer a wide range of experience and knowledge.
Answering the questions separately, in their respective cities, they still
formed a consensus. They agree the future looks promising for welding. It
remains and will continue to be a productive, cost-effective manufacturing
method. However, steps must be taken to bring more skilled personnel into the
industry, or changes must be made to accommodate for the lack of skilled
personnel (e.g., welding automation). They also indicated the welding industry
must embrace all of the modern-day technological tools to keep pace with the
rest of the world.

After reading activity

Continue the list of optimistic and pessimistic scenarios
for welding technology development in the future.

“projections
  for the future are generally optimistic…”

“but a few gray clouds
  roam the horizon”

1.
  Welding is here to stay and will be used more in the future.
2.
  The consumer welding market will continue to provide
  opportunities for growth. 3. …

1.
  Designs will be more efficient to minimize the amount of
  welding.
2.
  There will be a decline in the use of gas metal arc (GMAW) and
  gas tungsten arc welding (GTAW).
3.
  …

Translate the following sentences into Russian:

1.   Производители
сварочного оборудования, приспособлений и присадочного материала уверены, что
их рынок сбыта будет в дальнейшем расширяться.
2.   Технологии
получения механических соединений будут вытесняться в промышленности полу- и
автоматическими технологиями соединений, что приведет к дальнейшему развитию
сварки.
3.   Для сварки
новых металлов потребуется большая точность.
4.   Даже на малых
предприятиях могут появиться роботы и оборудование с числовым программным
управлением.
5.   Для успешного
развития сварочных технологий необходимо привлекать высококвалифицированный
персонал.
6.   Стремление к
увеличению производительности и сокращению расходов делает необходимым
дальнейшую автоматизацию сварочного производства.
7.   Поглощение и
слияние компаний, занятых в сфере производства сварочного оборудования и
расходных материалов, будет в ближайшее время продолжаться.
8.   Научные
исследования и опытно-конструкторские разработки положительно сказываются на
качестве сварочного оборудования и расходных материалах.
9.   Сварка в
настоящее время остается одним из эффективных и рентабельных технологических
процессов.
PART 7. HEALTH,
SAFETY AND ACCIDENT PREVENTION

In this part guidelines are given on the principal
health and safety considerations to ensure safe welding practices and prevent
accidents. Health risks associated with fume and gases generated during welding
are highlighted.

Pre reading activity

Think and say:

1.    Do you
think welding is a dangerous/hazardous profession?
2.    What
type/types of welding do you consider the most/least hazardous?
Why?

Vocabulary

irritation

раздражение

respiratory tract

дыхательные пути

susceptibility

чувствительность;
  восприимчивость

fever

жар, лихорадка; какое-л.
  заболевание, основным симптомом которого является очень высокая температура

tickling

першение (в горле)

chest tightness

стесненное дыхание

flu

грипп

coughing

кашель

limb

конечность (человека или
  животного)

siderosis

сидероз

pneumonia

воспаление легких,
  пневмония

pulmonary oedema

отек легких

asphyxiation

удушье

exposure

подвергание какому-л.
  воздействию; выставление, оставление на солнце, под дождем и т. п.

cancer

рак

Reading

Text 1. Health Risks of Welding Fume/Gases

What is welding fume/gases?
Welding fume is a
mixture of airborne fine particles. Toxic gases may also be generated during
welding and cutting.
Particulate fume
More than 90% of the particulate
fume arises from vaporisation of the consumable electrode, wire or rod as
material is transferred across the arc or flame. The range of welding particles
size is shown in relation to the more familiar types of dust and fume. The
respirable fraction of particles (especially less than 3µm) are potentially the
more harmful as they can penetrate to the innermost parts of the lung.
Gases Gases encountered in
welding may be:
-
Fuel gases which, on combustion, form carbon dioxide and, if the
flame is reducing, carbon monoxide;
-
Shielding gases such as argon, helium and carbon dioxide, either
alone or in mixtures with oxygen or hydrogen;
-
Carbon dioxide and monoxide produced by the action of heat on the
welding flux or slag;
-
Nitric oxide, nitrogen dioxide and ozone produced by the action
of heat or ultraviolet radiation on the atmosphere surrounding the welding
arc;  - Gases from the degradation of solvent vapours or surface contaminants
on the metal.
The degree of risk to the welder's health from
fume/gases will depend on composition, concentration, the length of time the
welder is exposed, the welder's susceptibility.

Health hazards from particulate
fume The potential hazards from breathing in particulate fume are:
1.
Irritation of the respiratory tract.  Fine
particles can cause dryness of the throat, tickling, coughing and
if the concentration is particularly high, tightness of the chest and
difficulty in breathing.
2.
Metal fume fever. Breathing in metal oxides such as
zinc and copper can lead to an acute flu-like illness called 'metal fume
fever'. It most commonly
occurs when welding galvanised steel; symptoms usually
begin several hours after exposure with a thirst, cough, headache, sweat, pain
in the limbs and fever. Complete recovery usually occurs within 1 to 2
days of removal from the exposure, without any lasting effects.
3.
Longer term effects. The continued inhalation of
welding fume over long periods of time can lead to the deposition of iron
particles in the lung, giving rise to a benign condition called siderosis.
There is evidence that welders have a slightly greater risk of developing lung cancer
than the general population. In certain welding situations, there is
potential for the fume to contain certain forms of chromium and/or nickel
compounds - substances which have been associated with lung cancer in processes
other than welding. As yet, no direct link has been clearly established.
Nevertheless, as a sensible precaution and to minimise the risk, special
attention should be paid to controlling fumes which may contain them.

Additional
hazards
A number of other specific
substances known to be hazardous to health can be found in welding fume such as
barium and fluorides which do not originate from the metal. If the metal
contains a surface coating, there will also be a potential risk from any toxic
substances generated by thermal degradation of the coating.

Health
hazards from gases
The
potential hazards from breathing in gases during welding are:
1.
Irritation of the respiratory tract. Ozone can cause
delayed irritation of the respiratory tract which may progress to bronchitis
and occasionally pneumonia. Nitrogen oxides can cause a dry irritating cough
and chest tightness. Symptoms usually occur after a delay of 4 to 8
hours. In severe cases, death can occur from pulmonary oedema (fluid on
the lungs) or pneumonia.
2.
Asphyxiation. There may be a risk of asphyxiation due
to replacement of air with gases produced when welding in a workshop or area
with inadequate ventilation. Special precautions are needed when welding in
confined spaces where there is the risk of the build up of inert shielding
gases. Carbon monoxide, formed as a result of incomplete combustion of fuel
gases, can also cause asphyxiation by replacing the oxygen in the blood.

Establishing
safe levels of fume in the workplace
The COSHH Regulations* require that exposure
is controlled below specific limits. The limits, known as occupational exposure
limits, are detailed in EH 40 which is revised periodically. The majority of
limits listed are for single substances. Only a few relate to substances which
are complex mixtures; welding fume is one of these. It has an occupational
exposure limit but account must also be taken of the exposure limits of the
individual constituents. So, in considering what would be safe exposure levels
to welding fume, not only should exposure be controlled to within the welding
fume limit but also the individual components must be controlled to within
their own limits. The assessment of exposure to fume from welding processes is
covered in EH 54.
Substances may have a maximum
exposure limit (MEL) or an occupation exposure standard (OES).
A MEL is the maximum concentration
of an airborne substance to which people may be exposed under any
circumstances. Exposure must be reduced as far as is reasonably practicable and
at least below any MEL.
An OES is the concentration of an airborne substance,
for which (according to current information) there is no evidence that it is
likely to cause harm to a person's health , even if they are exposed day after
day. Control is thought to be adequate if exposure is reduced to or below the
standard.
The OESs and the MELs of some of the
substances found in welding fume are listed in Table below; the absence of
other substances from this list does not indicate that they are safe.

Table. Occupational Exposure Limits

8hr TWA

15 min
STEL

Substances Assigned a
  Maximum Exposure Limit

Beryllium

0.002 mg/m 3

Cadmium oxide fume (as Cd)

0.025 mg/m 3

Chromium VI compounds (as
  Cr)

0.05
  mg/m
3

Cobalt

0.1
  mg/m 3

Nickel (insoluble
  compounds)

0.5
  mg/m 3

Substances Assigned an
  Occupational Exposure Standard

Welding fume

5 mg/m 3

Fluoride (as F)

2.5
  mg/m 3

Iron oxide, fume (as Fe)

5 mg/m 3

10 mg/m 3

Zinc oxide, fume

5 mg/m 3

10 mg/m 3

Manganese, fume (as Mn)

0.5
  mg/m 3

Ozone

0.2 ppm

Nitric Oxide

1 ppm

Nitrogen dioxide                                                    1 ppm

Chromium III compounds (as
  Cr)

0.5
  mg/m 3

Barium compounds, soluble
  (as Ba)

0.5
  mg/m 3

Carbon monoxide

50 ppm

300 ppm

Copper fume

0.2
  mg/m 3

If the fume contains only substances
such as iron or aluminium which are of low toxicity, an 8 hour (TWA) OES of
5mg/m3 applies; this figure is the average concentration of particulate fume
that should not be exceeded in an 8 hour day.
* Control of Substances Hazadous to Health (COSHH)
Regulations.
The Control of Substances Hazardous to Health (COSSH)
Regulations 2002 require employers to monitor the safe use of chemicals and
hazardous substances at work. It requires them to: control exposure to hazardous
substances to prevent ill health both now and any future cumulative effects
they may have, protect both employees and others who might be exposed, compile
records of employees using these materials, supply employees with suitable
personal protective equipment.

After reading activity

Think of Russian equivalents for the following word
combinations from the text:
Innermost parts of the lung, fuel
gas, fine particles, respirable fraction of particles, carbon dioxide,
ultraviolet radiation, galvanised steel, lasting effects, welding situations,
lung cancer, sensible precaution, surface coating, general population, inadequate
ventilation, risk of the build up of inert shielding gases, incomplete
combustion, occupational exposure limit, to cause harm to a person's health.

Speaking

True or false?

1.   The smaller the
particles the more harmful the fume is.
2.   The risk to the
welder's health from fume or gases depends on the welding arc.
3.   Welders have
lung cancer more often than the general population.
4.   Asphyxiation
may happen due to inadequate ventilation.
5.   Metal fume
fever is an incurable illness.

Fill in the gaps in the following sentences or complete
them:

1.       Argon
is a  … gas.
2.       Particulate
fume is very … for man’s health.
3.       When
exposed to particulate fume of high concentration for a long time, a welder may
… .
4.       Welding
galvanised steel may cause … .
5.       Asphyxiation
may happen due to … .
6.       To
minimise the risk, special attention should be paid to controlling fumes which
may contain chromium or …  compounds.
7.       In
case of metal fume fever, …. recovery occurs soon after removal of the welder
from the exposure.
8.       …
is a disease caused by fluid on the lungs.
9.       MEL
means maximum …  limit.
10.   OES is …
exposure standard.
11.   Gases
encountered in welding are … .

Answer the following questions:

1.   What is the
difference between welding fume and welding gas?
2.   What does the
major part of the particulate fume arise from?
3.   What does the
degree of risk to the welder's health from fume or gases depend on?
4.   Under what
condition is control over the exposure of welders to hazardous fumes or gases
considered adequate?
5.   Do the COSHH
Regulations state only single substances?

Vocabulary

bare spot

оголенный участок

wire feeder

механизм подачи
  (электродной или присадочной) проволоки

ground connection

1) заземление, замыкание на
  землю 2) соединение на корпус

power switch

переключатель мощности

rupture

а) пробой (изоляции) б)
  излом, разрушение, разрыв

confined space

замкнутый объём, замкнутое
  пространство

exhaust hood

вытяжной шкаф; вытяжной
  колпак

Reading

Text 2. Safety and Scheduled Maintenance Protect
Your Welding Assets

Q:
What can I do to avoid electrical shocks?
A: Wet working conditions must be avoided, because
water is an excellent conductor and electricity will always follow the path of
least resistance. Even a person's perspiration can lower the body's resistance
to electrical shock. Poor connections and bare spots on cables further
increase the possibility of electrical shock, and therefore, daily inspection
of these items is recommended. Equipment operators should also routinely
inspect for proper ground connections.
Q:
How can I inspect and maintain my wire feeder?
A: Periodically inspect the electrode wire drive
rolls. If dirty, remove the drive rolls and clean with a wire brush. Deformed
drive rolls should be replaced. Drive rolls should be changed, adjusted or
cleaned only when the wire feeder is shut off. In addition, check the inlet and
outlet guides and replace if they are deformed from wire wear. Remember that
when power is applied to a wire feeder, fingers should be kept away from the
drive roll area.
Q:
What are some important electrode safety considerations?
A: Welding power sources for use with MIG and TIG
welding normally are equipped with devices that permit on/off control of the
welding power output. If so, the electrode becomes electrically hot when the
power source switch is ON and the welding gun switch is closed. Never touch the
electrode wire or any conducting object in contact with the electrode circuit,
unless the welding power source is off. Welding power sources used for shielded
metal arc welding (SMAW or Stick welding) may not be equipped with welding
power output on/off control devices. With such equipment, the electrode is
electrically hot when the power switch is turned ON.
Q:
How should I store my gas cylinders?
A: Cylinders should be securely fastened at all times.
Chains are usually used to secure a cylinder to a wall or cylinder cart. When
moving or storing a cylinder, a threaded protector cap must be fastened to the
top of the cylinder. This protects the valve system should it be bumped or
dropped. Cylinders should not be stored or used in a horizontal position. This
is because some cylinders contain a liquid which would leak out or be forced
out if the cylinder was laid in a flat position. Also, welding guns and other
cables should not be hung on or near cylinders. A gun could cause an arc
against the cylinder wall or valve assembly, possibly resulting in a weakened
cylinder or even a rupture.
Q:
How can I tell if my regulator is faulty?
A: The following symptoms indicate a faulty
regulator:
Leaks - if gas leaks externally.
Excessive сreep - if delivery pressure continues to
rise with the downstream valve closed.
Faulty gauge - if gauge pointer does not move off the
stop pin when pressurized, nor returns to the stop pin after pressure release.
Do not attempt to repair a faulty regulator. It should be sent to your
designated repair center, where special techniques and tools are used by
trained personnel.
Q:
What are some tips for a safe welding environment?
A: The area surrounding the welder will be subjected
to light, heat, smoke, sparks and fumes. Permanent booths or portable
partitions can be used to contain light rays in one area. The heat and sparks
given off are capable of setting flammable materials on fire. Therefore,
welding should not be done in areas containing flammable gases, vapors, liquids
or dusty locations where explosions are a possibility. Metals with plating,
coatings or paint that come near the region of the arc may give off smoke and
fumes during welding. These fumes may pose a health hazard to the lungs,
therefore an exhaust hood or booth should be used to remove fumes from
the area. When welding in confined spaces, such as inside tanks, large
containers or even compartments of a ship, toxic fumes may gather. Also, in an
enclosed room, breathable oxygen can be replaced by shielding gases used for
welding or purging. Care must be taken to ensure enough clean air for
breathing. In many companies, it is routine to provide welders with air masks
or selfcontained breathing equipment.
Q:
How should an operator dress for optimum safety?
A: Gloves and clothing should be flame-resistant.
Clothing made from a dark-colored, tightly woven material is best suited for
welding. Gauntlet-type leather gloves should be worn to protect the hands and
wrists. Shirt collars and shirt cuffs should be buttoned, and open front
pockets are not advisable as they may catch sparks. Also, operators should
never store matches or lighters in their pockets. Pants cuffs are not
recommended, as they will also catch sparks. Tennis shoes do not qualify as
adequate foot protection. Hightop leather shoes or boots are absolutely
necessary.
Q:
Is there a daily maintenance schedule I should follow?
A: Below is a general engine drive routine daily
maintenance schedule, but it should be modified according to a company's specific
conditions. By following a regimen of appropriate and thorough maintenance and
safety, a welder from Miller Electric can run dependably for decades. Designed
to withstand rough use, these machines use high quality components and are
tested for durability.

After reading activity

Find the Russian equivalents for the following
English word combinations: electrical shock, daily inspection, wire brush,
power sources, flammable gases, cylinder cart, toxic fumes, open front pockets,
toxic substances, flat position, airborne substance, trained personnel, air
mask, flame-resistant.

Find the English equivalents in the text for the
following word combinations: путь наименьшего сопротивления, поражение
электрическим током, соображения безопасности, защитный колпак, обученный
персонал, наносить вред, грубое обращение.

Speaking

Answer each of the above questions in just one sentence:

Model:
Q: What can I do to avoid electrical shocks?

A: To avoid electrical shocks you should not operate
in wet working conditions check your circuit for poor connections and bare
spots.

Look
at a Maintenance Schedule Chart below and say what a welder should do in terms
of maintenance: - once a working day; - once a week; - once a month.

Maintenance Schedule Chart

8 Hours

Wipe up oil and fuel spills
  immediately
Check fluid levels (oil
  & fuel)
Service the air filter
  (refer to engine manual for specifics)

50 Hours

Service air filter element
  (refer to engine manual for specifics)  Clean and tighten weld terminals

100
Hours

Change oil
Change oil filter (refer to
  engine manual for specifics)
Clean and tighten battery
  connections
Clean cooling system (refer
  to engine manual for specifics)

200
Hours

Replace unreadable labels
  (order from parts list)
Replace fuel filter
Check valve clearance
  (refer to engine manual for specifics)

250
Hours

Check and clean spark
  arrestor

500
Hours

Tape or replace cracked
  cables
Clean/Set injectors (refer
  to engine manual for specifics)

1000
Hours

Blow out or vacuum inside
  equipment. During heavy service, do this monthly.

Answer the following questions:

1.   What should be
inspected daily by a welding operator to avoid electric shock?
2.   What should be
cleaned/ changed/ replaced while maintaining wire feeder?
3.   Why shouldn’t
you touch the electrode wire when the welding power source is on?
4.   Why shouldn’t
cylinders be stored or used in a horizontal position?
5.   Should you try
to repair a faulty regulator yourself?
6.   What are booths
and partitions used for?
7.   What shouldn’t
a welder store in his pockets?

Writing

Summarize the information of the text using the following
incomplete sentences as a plan:

1.   To avoid
electrical shocks a welder should/shouldn’t… (inspect, repair, etc.)
2.   The following
things should be remembered when inspecting and maintaining wire feeder … .
3.   To use and
store electrodes safely, one should/shouldn’t … .
4.   Gas cylinders
should be stored in the following way: … .
5.   If the
regulator is faulty, you can observe the following: … .
6.   Safe welding
environment is obtained by … .
7.   Welding
operators should be dressed in … .
8.   To keep welding
equipment running for decades, operator should do some operations on a regular
basis, such as … .

APPENDIX
1. WELDING THEORY & APPLICATION DEFINITIONS

ACETONE:
A flammable, volatile liquid used in acetylene
cylinders to dissolve and stabilize acetylene under high pressure.
ACETYLENE:
A highly combustible gas composed of carbon and
hydrogen. Used as a fuel gas in the oxyacetylene welding process.
ACTUAL THROAT:
See THROAT OF FILLET WELD.
AIR-ACETYLENE:
A low temperature flare produced by burning acetylene
with air instead of oxygen.
AIR-ARC CUTTING:
An arc cutting process in which metals to be cut are
melted by the heat of the carbon arc.
ALLOY:
A mixture with metallic properties composed of two or
more elements, of which at least one is a metal.
ALTERNATING CURRENT:
An electric current that reverses its direction at
regularly recurring intervals.
AMMETER:
An
instrument for measuring electrical current in amperes by an indicator
activated by the movement of a coil in a magnetic field or by the longitudinal
expansion of a wire carrying the current.
ANNEALING:
A
comprehensive term used to describe the heating and cooling cycle of steel in
the solid state. The term annealing usually implies relatively slow cooling. In
annealing, the temperature of the operation, the rate of heating and cooling,
and the time the metal is held at heat depend upon the composition, shape, and
size of the steel product being treated, and the purpose of the treatment. The
more important purposes for which steel is annealed are as follows: to remove
stresses; to induce softness; to alter ductility, toughness, electric,
magnetic, or other physical and mechanical properties; to change the
crystalline structure; to remove gases; and to produce a definite
microstructure.
ARC BLOW:
The deflection of an electric arc from its normal
path because of magnetic forces.
ARC BRAZING:
A brazing
process wherein the heat is obtained from an electric arc formed between the
base metal and an electrode, or between two electrodes.
ARC CUTTING:
A
group of cutting processes in which the cutting of metals is accomplished by
melting with the heat of an arc between the electrode and the base metal. See
CARBON-ARC CUTTING, METAL-ARC
CUTTING, ARC-OXYGEN CUTTING, AND AIR-ARC CUTTING.
ARC LENGTH:
The distance between the tip of the electrode and the
weld puddle.
ARC-OXYGEN CUTTING:
An oxygen-cutting process used to sever metals by a
chemical reaction of oxygen with a base metal at elevated temperatures.
ARC VOLTAGE:
The voltage across the welding arc.
ARC WELDING:
A group of welding processes in which fusion is
obtained by heating with an electric arc or arcs, with or without the use of
filler metal.
AS WELDED:
The
condition of weld metal, welded joints, and weldments after welding and prior
to any subsequent thermal, mechanical, or chemical treatments.
ATOMIC HYDROGEN WELDING:
An
arc welding process in which fusion is obtained by heating with an arc
maintained between two metal electrodes in an atmosphere of hydrogen. Pressure
and/or filler metal may or may not be used.
AUSTENITE:
The
non-magnetic form of iron characterized by a face-centered cubic lattice
crystal structure. It is produced by heating steel above the upper critical
temperature and has a high solid solubility for carbon and alloying elements.
AXIS OF A WELD:
A line through the length of a weld, perpendicular to
a cross section at its center of gravity.
BACK FIRE:
The momentary burning back of a flame into the tip,
followed by a snap or pop, then immediate reappearance or burning out of the
flame.
BACK PASS:
A pass made to deposit a back weld.
BACK UP:
In flash and upset welding, a locator used to
transmit all or a portion of the upsetting force to the workpieces.
BACK WELD:
A weld deposited at the back of a single groove
weld.
BACKHAND WELDING:
A welding technique in which the flame is directed
towards the completed weld.
BACKING STRIP:
A
piece of material used to retain molten metal at the root of the weld and/or
increase the thermal capacity of the joint so as to prevent excessive warping
of the base metal.
BACKING WELD:
A weld bead applied to the root of a single groove
joint to assure complete root penetration.
BACKSTEP:
A sequence in which weld bead increments are
deposited in a direction opposite to the direction of progress.
BARE ELECTRODE:
An arc welding electrode that has no coating other
than that incidental to the drawing of the wire.
BARE METAL-ARC WELDING:
An arc welding process in which fusion is obtained by
heating with an unshielded arc between a bare or lightly coated electrode and
the work.
Pressure is not used and filler metal is obtained
from the electrode.
BASE METAL:
The metal to be welded or cut. In alloys, it is the
metal present in the largest proportion.
BEAD WELD:
A type of weld composed of one or more string or
weave beads deposited on an unbroken surface.
BEADING:
See STRING BEAD WELDING and WEAVE BEAD.
BEVEL ANGLE:
The angle formed between the prepared edge of a
member and a plane perpendicular to the surface of the member.
BLACKSMITH WELDING:
See FORGE WELDING.
BLOCK BRAZING:
A
brazing process in which bonding is produced by the heat obtained from heated
blocks applied to the parts to be joined and by a nonferrous filler metal
having a melting point above 800 °F (427 °C), but below that of the base metal.
The filler metal is distributed in the joint by capillary attraction.
BLOCK SEQUENCE:
A
building up sequence of continuous multipass welds in which separated lengths
of the weld are completely or partially built up before intervening lengths are
deposited. See BUILDUP SEQUENCE.
BLOW HOLE:  see GAS POCKET.
BOND:
The junction of the welding metal and the base
metal.
BOXING:
The operation of continuing a fillet weld around a
corner of a member as an extension of the principal weld.
BRAZING:
A
group of welding processes in which a groove, fillet, lap, or flange joint is
bonded by using a nonferrous filler metal having a melting point above 800 °F
(427 °C), but below that of the base metals. Filler metal is distributed in the
joint by capillary attraction.
BRAZE WELDING:
A
method of welding by using a filler metal that liquefies above 450 °C (842 °F)
and below the solid state of the base metals. Unlike brazing, in braze welding,
the filler metal is not distributed in the joint by capillary action.
BRIDGING:
A welding defect caused by poor penetration. A void
at the root of the weld is spanned by weld metal.
BUCKLING:
Distortion caused by the heat of a welding process.
BUILDUP SEQUENCE:
The order in which the weld beads of a multipass weld
are deposited with respect to the cross section of a joint. See BLOCK
SEQUENCE.
BUTT JOINT:
A joint between two workpieces in such a manner that
the weld joining the parts is between the surface planes of both of the pieces
joined.
BUTT WELD:
A weld in a butt joint.
BUTTER WELD:
A weld caused of one or more string or weave beads
laid down on an unbroken surface to obtain desired properties or dimensions.
CAPILLARY ATTRACTION:
The
phenomenon by which adhesion between the molten filler metal and the base metals,
together with surface tension of the molten filler metal, causes distribution
of the filler metal between the properly fitted surfaces of the joint to be
brazed.
CARBIDE PRECIPITATION:
A
condition occurring in austenitic stainless steel which contains carbon in a
supersaturated solid solution. This condition is unstable. Agitation of the
steel during welding causes the excess carbon in solution to precipitate. This
effect is also called weld decay.
CARBON-ARC CUTTING:
A process of cutting metals with the heat of an arc
between a carbon electrode and the work.
CARBON-ARC WELDING:
A
welding process in which fusion is produced by an arc between a carbon
electrode and the work. Pressure and/or filler metal and/or shielding may or
may not be used.
CARBONIZING FLAME:
An oxyacetylene flame in which there is an excess of
acetylene. Also called excess acetylene or reducing flame.
CASCADE SEQUENCE: Subsequent beads are stopped short
of a previous bead, giving a cascade effect.
CASE HARDENING:
A
process of surface hardening involving a change in the composition of the outer
layer of an iron base alloy by inward diffusion from a gas or liquid, followed
by appropriate thermal treatment. Typical hardening processes are carbonizing,
cyaniding, carbonitriding, and nitriding.
CHAIN INTERMITTENT FILLET WELDS:
Two lines of intermittent fillet welds in a T or lap
joint in which the welds in one line are approximately opposite those in the
other line.
CHAMFERING:
The preparation of a welding contour, other than for
a square groove weld, on the edge of a joint member.
COALESCENCE:
The uniting or fusing of metals upon heating.
COATED ELECTRODE:
An
electrode having a flux applied externally by dipping, spraying, painting, or
other similar methods. Upon burning, the coat produces a gas which envelopes
the arc.
COMMUTORY CONTROLLED WELDING:
The
making of a number of spot or projection welds in which several electrodes, in
simultaneous contact with the work, progressively function under the control of
an electrical commutating device.
COMPOSITE ELECTRODE:
A
filler metal electrode used in arc welding, consisting of more than one metal
component combined mechanically. It may or may not include materials that improve
the properties of the weld, or stabilize the arc.
COMPOSITE JOINT:
A joint in which both a thermal and mechanical
process are used to unite the base metal parts.
CONCAVITY:
The maximum perpendicular distance from the face of a
concave weld to a line joining the toes.
CONCURRENT HEATING:
Supplemental heat applied to a structure during the
course of welding.
CONE:
The conical part of a gas flame next to the orifice
of the tip.
CONSUMABLE INSERT:
Preplaced filler metal which is completely fused into
the root of the joint and becomes part of the weld.
CONVEXITY:
The maximum perpendicular distance from the face of a
convex fillet weld to a line joining the toes.
CORNER JOINT:
A joint between two members located approximately at
right angles to each other in the form of an L.
COVER GLASS:
A clear glass used in goggles, hand shields, and
helmets to protect the filter glass from spattering material.
COVERED ELECTRODE:
A
metal electrode with a covering material which stabilizes the arc and improves
the properties of the welding metal. The material may be an external wrapping
of paper, asbestos, and other materials or a flux covering.
CRACK:
A fracture type discontinuity characterized by a
sharp tip and high ratio of length and width to opening displacement.
CRATER:
A depression at the termination of an arc weld.
CRITICAL TEMPERATURE:
The transition temperature of a substance from one
crystalline form to another.
CURRENT DENSITY:
Amperes per square inch of the electrode cross
sectional area.
CUTTING TIP:
A gas torch tip especially adapted for cutting.
CUTTING TORCH:
A device used in gas cutting for controlling the
gases used for preheating and the oxygen used for cutting the metal.
CYLINDER:
A portable cylindrical container used for the storage
of a compressed gas.
DEFECT:
A discontinuity or discontinuities which, by nature
or accumulated effect (for example, total crack length), render a part or
product unable
to meet the minimum applicable acceptance standards
or specifications. This term designates rejectability.
DEPOSITED METAL:
Filler metal that has been added during a welding
operation.
DEPOSITION EFFICIENCY:
The ratio of the weight of deposited metal to the net
weight of electrodes consumed, exclusive of stubs.
DEPTH OF FUSION:
The distance from the original surface of the base
metal to that point at which fusion ceases in a welding operation.
DIE:
a. Resistance
Welding. A member, usually shaped to the work contour, used to clamp the
parts being welded and conduct the welding current.  b. Forge Welding. A
device used in forge welding primarily to form the work while hot and apply the
necessary pressure.
DIE WELDING:
A forge welding process in which fusion is produced
by heating in a furnace and by applying pressure by means of dies.
DIP BRAZING:
A
brazing process in which bonding is produced by heating in a molten chemical or
metal bath and by using a nonferrous filler metal having a melting point above
800 °F (427 °C), but below that of the base metals. The filler metal is
distributed in the joint by capillary attraction. When a metal bath is used,
the bath provides the filler metal.
DIRECT CURRENT ELECTRODE NEGATIVE (DCEN):
The
arrangement of direct current arc welding leads in which the work is the
positive pole and the electrode is the negative pole of the welding arc.
DIRECT CURRENT ELECTRODE POSITIVE (DCEP):
The
arrangement of direct current arc welding leads in which the work is the
negative pole and the electrode is the positive pole of the welding arc.
DISCONTINUITY:
An
interruption of the typical structure of a weldment, such as lack of
homogeneity in the mechanical, metallurgical, or physical characteristics of
the material or weldment. A discontinuity is not necessarily a defect.
DRAG:
The horizontal distance between the point of entrance
and the point of exit of a cutting oxygen stream.
DUCTILITY:
The
property of a metal which allows it to be permanently deformed, in tension,
before final rupture. Ductility is commonly evaluated by tensile testing in
which the amount of elongation and the reduction of area of the broken
specimen, as compared to the original test specimen, are measured and
calculated.
DUTY CYCLE:
The
percentage of time during an arbitrary test period, usually 10 minutes, during
which a power supply can be operated at its rated output without overloading.
EDGE JOINT:
A joint between the edges of two or more parallel or
nearly parallel members.
EDGE PREPARATION:
The contour prepared on the edge of a joint member
for welding.
EFFECTIVE LENGTH OF WELD:
The length of weld throughout which the correctly
proportioned cross section exits.
ELECTRODE:
a.
Metal-Arc. Filler metal in the form of a wire or rod, whether
bare or covered, through which current is conducted between the electrode
holder and the arc.
b.
Carbon-Arc. A carbon or graphite rod through which current
is conducted between the electrode holder and the arc.
c.Atomic . One of the two tungsten rods
between the points of which the arc is maintained.
d.
Electrolytic Oxygen-Hydrogen Generation. The conductors by which
current enters and leaves the water, which is decomposed by the passage of the
current.
e.
Resistance Welding. The part or parts of a resistance welding
machine through which the welding current and the pressure are applied directly
to the work.
ELECTRODE FORCE:
a.
Dynamic. In spot, seam, and projection welding, the force
(pounds) between the electrodes during the actual welding cycle.
b.
Theoretical. In spot, seam, and projection welding, the force,
neglecting friction and inertia, available at the electrodes of a resistance
welding machine by virtue of the initial force application and the theoretical
mechanical advantage of the system.
c.
Static. In spot, seam, and projection welding, the force between
the electrodes under welding conditions, but with no current flowing and no
movement in the welding machine.
ELECTRODE HOLDER:
A device used for mechanically holding the electrode
and conduct- ing current to it.
ELECTRODE SKID:
The sliding of an electrode along the surface of the
work during spot, seam, or projection welding.
EMBOSSMENT:
A rise or protrusion from the surface of a metal.
ETCHING:
A process of preparing metallic specimens and welds
for macrographic or micrographic examination.
FACE REINFORCEMENT:
Reinforcement of weld at the side of the joint from
which welding was done.
FACE OF WELD:
The exposed surface of a weld, made by an arc or gas
welding process, on the side from which welding was done.
FAYING SURFACE:
That surface of a member that is in contact with
another member to which it is joined.
FERRITE:
The
virtually pure form of iron existing below the lower critical temperature and
characterized by a body-centered cubic lattice crystal structure. It is
magnetic and has very slight solid solubility for carbon.
FILLER METAL:
Metal to be added in making a weld.
FILLET WELD:
A weld of approximately triangular cross section, as
used in a lap joint, joining two surfaces at approximately right angles to each
other.
FILTER GLASS:
A colored glass used in goggles, helmets, and shields
to exclude harmful light rays.
FLAME CUTTING:  see OXYGEN
CUTTING.
FLAME GOUGING:
See OXYGEN GOUGING.
FLAME HARDENING:
A method for hardening a steel surface by heating
with a gas flame followed by a rapid quench.
FLAME SOFTENING:
A method for softening steel by heating with a gas
flame followed by slow cooling.
FLASH:
Metal and oxide expelled from a joint made by a
resistance welding process.
FLASH WELDING:
A
resistance welding process in which fusion is produced, simultaneously over the
entire area of abutting surfaces, by the heat obtained from resistance to the
flow of current between two surfaces and by the application of pressure after
heating is substantially completed. Flashing is accompanied by expulsion of
metal from the joint.
FLASHBACK:
The burning of gases within the torch or beyond the
torch in the hose, usually with a shrill, hissing sound.
FLAT POSITION:
The position in which welding is performed from the
upper side of the joint and the face of the weld is approximately horizontal.
FILM BRAZING:
A
process in which bonding is produced by heating with a molten nonferrous filler
metal poured over the joint until the brazing temperature is attained. The
filler metal is distributed in the joint by capillary attraction. See BRAZING.

FLOW WELDING:
A
process in which fusion is produced by heating with molten filler metal poured
over the surfaces to be welded until the welding temperature is attained and
the required filler metal has been added.
The filler metal is not distributed in the joint by
capillary attraction.
FLUX:
A cleaning agent used to dissolve oxides, release
trapped gases and slag, and to cleanse metals for welding, soldering, and
brazing.
FOREHAND WELDING:
A gas welding technique in which the flare is
directed against the base metal ahead of the completed weld.
FORGE WELDING:
A group of welding processes in which fusion is
produced by heating in a forge or furnace and applying pressure or blows.
FREE BEND TEST:
A method of testing weld specimens without the use of
a guide.
FULL FILLET WELD:
A fillet weld whose size is equal to the thickness of
the thinner member joined.
FURNACE BRAZING:
A
process in which bonding is produced by the furnace heat and a nonferrous
filler metal having a melting point above 800 °F (427 °C), but below that of
the base metals. The filler metal is distributed in the joint by capillary
attraction.
FUSION:
A
thorough and complete mixing between the two edges of the base metal to be
joined or between the base metal and the filler metal added during welding.
FUSION ZONE (FILLER PENETRATION):
The area of base metal melted as determined on the
cross section of a weld.
GAS CARBON-ARC WELDING:
An
arc welding process in which fusion is produced by heating with an electric arc
between a carbon electrode and the work. Shielding is obtained from an inert
gas such as helium or argon. Pressure and/or filler metal may or may not be
used.
GAS METAL-ARC (MIG) WELDING (GMAW):
An
arc welding process in which fusion is produced by heating with an electric arc
between a metal electrode and the work. Shielding is obtained from an inert gas
such as helium or argon. Pressure and/or filler metal may or my not be used.
GAS POCKET:
A weld cavity caused by the trapping of gases
released by the metal when cooling.
GAS TUNGSTEN-ARC (TIG) WELDING (GTAW):
An
arc welding process in which fusion is produced by heating with an electric arc
between a tungsten electrode and the work while an inert gas forms around the
weld area to prevent oxidation. No flux is used.
GAS WELDING:
A process in which the welding heat is obtained from
a gas flame.
GLOBULAR TRANSFER (ARC WELDING):
A type of metal transfer in which molten filler metal
is transferred across the arc in large droplets.
GOGGLES:
A device with colored lenses which protect the eyes
from harmful radiation during welding and cutting operations.
GROOVE:
The opening provided between two members to be joined
by a groove weld.
GROOVE ANGLE:
The total included angle of the groove between parts
to be joined by a groove weld.
GROOVE FACE:
That surface of a member included in the groove.
GROOVE RADIUS:
The radius of a J or U groove.
GROOVE WELD:
A weld made by depositing filler metal in a groove
between two members to be joined.
GROUND CONNECTION:
The connection of the work lead to the work.
GROUND LEAD:
See WORK LEAD.
GUIDED BEND TEST:
A bending test in which the test specimen is bent to
a definite shape by means of a jig.
HAMMER WELDING:
A forge welding process.
HAND SHIELD:
A device used in arc welding to protect the face and
neck. It is equipped with a filter glass lens and is designed to be held by
hand.
HARD FACING:
A
particular form of surfacing in which a coating or cladding is applied to a
surface for the main purpose of reducing wear or loss of material by abrasion,
impact, erosion, galling, and cavitations.
HARD SURFACING:
The application of a hard, wear-resistant alloy to
the surface of a softer metal.
HARDENING:
a.
The heating and quenching of certain iron-base alloys from a temperature
above the critical temperature range for the purpose of producing a hardness
superior to that obtained when the alloy is not quenched. This term is usually
restricted to the formation of martensite.
b.
Any process of increasing the hardness of metal by suitable
treatment, usually involving heating and cooling.
HEAT AFFECTED ZONE:
That portion of the base metal whose structure or
properties have been changed by the heat of welding or cutting.
HEAT TIME:
The duration of each current impulse in pulse
welding.
HEAT TREATMENT:
An
operation or combination of operations involving the heating and cooling of a
metal or an alloy in the solid state for the purpose of obtaining certain
desirable conditions or properties. Heating and cooling for the sole purpose of
mechanical working are excluded from the meaning of the definition.
HEATING GATE:
The opening in a thermit mold through which the parts
to be welded are preheated.
HELMET:
A device used in arc welding to protect the face and
neck. It is equipped with a filter glass and is designed to be worn on the
head.
HOLD TIME:
The time that pressure is maintained at the
electrodes after the welding current has stopped.
HORIZONTAL WELD:
A
bead or butt welding process with its linear direction horizontal or inclined
at an angle less than 45 degrees to the horizontal, and the parts welded being
vertically or approximately vertically disposed.
HORN:
The electrode holding arm of a resistance spot
welding machine.
HORN SPACING:
In a
resistance welding machine, the unobstructed work clearance between horns or
platens at right angles to the throat depth. This distance is measured with the
horns parallel and horizontal at the end of the downstroke.
HOT SHORT:
A condition which occurs when a metal is heated to
that point, prior to melting, where all strength is lost but the shape is still
maintained.
HYDROGEN BRAZING:
A method of furnace brazing in a hydrogen
atmosphere.
HYDROMATIC WELDING:
See PRESSURE CONTROLLED WELDING.
HYGROSCOPIC:
Readily absorbing and retaining moisture.
IMPACT TEST:
A
test in which one or more blows are suddenly applied to a specimen. The results
are usually expressed in terms of energy absorbed or number of blows of a given
intensity required to break the specimen.
IMPREGNATED-TAPE METAL-ARC WELDING
An
arc welding process in which fusion is produced by heating with an electric arc
between a metal electrode and the work. Shielding is obtained from
decomposition of impregnated tape wrapped around the electrode as it is fed to
the arc. Pressure is not used, and filler metal is obtained from the
electrode.
INDUCTION BRAZING:
A
process in which bonding is produced by the heat obtained from the resistance
of the work to the flow of induced electric current and by using a nonferrous
filler metal having a melting point above 800 °F (427 °C), but below that of
the base metals. The filler metal is distributed in the joint by capillary
attraction.
INDUCTION WELDING:
A
process in which fusion is produced by heat obtained from resistance of the
work to the flow of induced electric current, with or without the application
of pressure.
INERT GAS:
A gas which does not normally combine chemically with
the base metal or filler metal.
INTERPASS TEMPERATURE:
In a multipass weld, the lowest temperature of the
deposited weld meal before the next pass is started.
JOINT:
The portion of a structure in which separate base
metal parts are joined.
JOINT PENETRATION:
The maximum depth a groove weld extends from its face
into a joint, exclusive of reinforcement.
KERF:
The space from which metal has been removed by a
cutting process.
LAP JOINT:
A joint between two overlapping members.
LAYER:
A stratum of weld metal, consisting of one or more
weld beads.
LEG OF A FILLET WELD:
The distance from the root of the joint to the toe of
the fillet weld.
LIQUIDUS:
The lowest temperature at which a metal or an alloy
is completely liquid.
LOCAL PREHEATING:
Preheating a specific portion of a structure.
LOCAL STRESS RELIEVING:
Stress relieving heat treatment of a specific portion
of a structure.
MANIFOLD:
A multiple header for connecting several cylinders to
one or more torch supply lines.
MARTENSITE:
Martensite
is a microconstituent or structure in quenched steel characterized by an
acicular or needle-like pattern on the surface of polish. It has the maximum
hardness of any of the structures resulting from the decomposition products of
austenite.
MASH SEAM WELDING:
A
seam weld made in a lap joint in which the thickness at the lap is reduced to
approximately the thickness of one of the lapped joints by applying pressure
while the metal is in a plastic state.
MELTING POINT:
The temperature at which a metal begins to liquefy.
MELTING RANGE:
The temperature range between solidus and liquidus.
MELTING RATE:
The weight or length of electrode melted in a unit of
time.
METAL-ARC CUTTING:
The process of cutting metals by melting with the
heat of the metal arc.
METAL-ARC WELDING:
An arc welding process in which a metal electrode is
held so that the heat of the arc fuses both the electrode and the work to form
a weld.
METALLIZING:
A method of overlay or metal bonding to repair worn
parts.
MIXING CHAMBER:
That part of a welding or cutting torch in which the
gases are mixed for combustion.
MULTI-IMPULSE WELDING:
The
making of spot, projection, and upset welds by more than one impulse of
current. When alternating current is used each impulse may consist of a
fraction of a cycle or a number of cycles.
NEUTRAL FLAME:
A gas flame in which the oxygen and acetylene volumes
are balanced and both gases are completely burned.
NICK BREAK TEST:
A
method for testing the soundness of welds by nicking each end of the weld, then
giving the test specimen a sharp hammer blow to break the weld from nick to
nick. Visual inspection will show any weld defects.
NONFERROUS:
Metals which contain no iron. Aluminum, brass,
bronze, copper, lead, nickel, and titanium are nonferrous.
NORMALIZING:
Heating
iron-base alloys to approximately 100 °F (38 °C) above the critical temperature
range followed by cooling to below that range in still air at ordinary
temperature.
NUGGET:
The fused metal zone of a resistance weld.
OPEN CIRCUIT VOLTAGE:
The voltage between the terminals of the welding
source when no current is flowing in the welding circuit.
OVERHEAD POSITION:
The position in which welding is performed from the
underside of a joint and the face of the weld is approximately horizontal.
OVERLAP:
The protrusion of weld metal beyond the bond at the
toe of the weld.
OXIDIZING FLAME:
An oxyacetylene flame in which there is an excess of
oxygen. The unburned excess tends to oxidize the weld metal.
OXYACETYLENE CUTTING:
An
oxygen cutting process in which the necessary cutting temperature is maintained
by flames obtained from the combustion of acetylene with oxygen.
OXYACETYLENE WELDING:
A welding process in which the required temperature
is attained by flames obtained from the combustion of acetylene with oxygen.
OXY-ARC CUTTING:
An
oxygen cutting process in which the necessary cutting temperature is maintained
by means of an arc between an electrode and the base metal.
OXY-CITY GAS CUTTING:
An
oxygen cutting process in which the necessary cutting temperature is maintained
by flames obtained from the combustion of city gas with oxygen.
OXYGEN CUTTING:
A process of cutting ferrous metals by means of the
chemical action of oxygen on elements in the base metal at elevated
temperatures.
OXYGEN GOUGING:
An application of oxygen cutting in which a chamfer
or groove is formed.
OXY-HYDROGEN CUTTING:
An
oxygen cutting process in which the necessary cutting temperature is maintained
by flames obtained from the combustion of city gas with oxygen.
OXY-HYDROGEN WELDING:
A
gas welding process in which the required welding temperature is attained by
flames obtained from the combustion of hydrogen with oxygen.
OXY-NATURAL GAS CUTTING:
An
oxygen cutting process in which the necessary cutting temperature is maintained
by flames obtained by the combustion of natural gas with oxygen.
OXY-PROPANE CUTTING:
An
oxygen cutting process in which the necessary cutting temperature is maintained
by flames obtained from the combustion of propane with oxygen.
PASS:
The weld metal deposited in one general progression
along the axis of the weld.
PEENING:
The
mechanical working of metals by means of hammer blows. Peening tends to stretch
the surface of the cold metal, thereby relieving contraction stresses.
PENETRANT INSPECTION:
a.
Fluorescent. A water washable penetrant with high fluorescence
and low surface tension. It is drawn into small surface openings by capillary
action. When exposed to black light, the dye will fluoresce.
b.
Dye. A process which involves the use of three noncorrosive
liquids. First, the surface cleaner solution is used. Then the penetrant is
applied and allowed to stand at least 5 minutes. After standing, the penetrant
is removed with the leaner solution and the developer is applied. The dye
penetrant, which has remained in the surface discontinuity, will be drawn to
the surface by the developer resulting in bright red indications.
PERCUSSIVE WELDING:
A
resistance welding process in which a discharge of electrical energy and the
application of high pressure occurs simultaneously, or with the electrical
discharge occurring slightly before the application of pressure.
PERLITE:
Perlite is the lamellar aggregate of ferrite and iron
carbide resulting from the direct transformation of austenite at the lower
critical point.
PITCH:
Center to center spacing of welds.
PLUG WELD:
A
weld is made in a hole in one member of a lap joint, joining that member to
that portion of the surface of the other member which is exposed through the
hole. The walls of the hole may or may not be parallel, and the hole may be
partially or completely filled with the weld metal.
POKE WELDING:
A
spot welding process in which pressure is applied manually to one electrode.
The other electrode is clamped to any part of the metal much in the same manner
that arc welding is grounded.
POROSITY:
The presence of gas pockets or inclusions in
welding.
POSITIONS OF WELDING:
All
welding is accomplished in one of four positions: flat, horizontal, overhead,
and vertical. The limiting angles of the various positions depend somewhat as
to whether the weld is a fillet or groove weld.
POSTHEATING:
The application of heat to an assembly after a
welding, brazing, soldering, thermal spraying, or cutting operation.
POSTWELD INTERVAL:
In
resistance welding, the heat time between the end of weld time, or weld
interval, and the start of hold time. During this interval, the weld is
subjected to mechanical and heat treatment.
PREHEATING:
The application of heat to a base metal prior to a
welding or cutting operation.
PRESSURE CONTROLLED WELDING:
The
making of a number of spot or projection welds in which several electrodes
function progressively under the control of a pressure sequencing device.
PRESSURE WELDING:
Any welding process or method in which pressure is
used to complete the weld.
PREWELD INTERVAL:
In
spot, projection, and upset welding, the time between the end of squeeze time
and the start of weld time or weld interval during which the material is
preheated. In flash welding, it is the time during which the material is
preheated.
PROCEDURE QUALIFICATION:
The demonstration that welds made by a specific
procedure can meet prescribed standards.
PROJECTION WELDING:
A
resistance welding process between two or more surfaces or between the ends of
one member and the surface of another. The welds are localized at predetermined
points or projections.
PULSATION WELDING:
A
spot, projection, or seam welding process in which the welding current is
interrupted one or more times without the release of pressure or change of
location of electrodes.
PUSH WELDING:
The
making of a spot or projection weld in which the force is aping current is
interrupted one or more times without the release of pressure or change of
location of electrodes.
PUSH WELDING:
The
making of a spot or projection weld in which the force is applied manually to
one electrode and the work or a backing bar takes the place of the other
electrode.
QUENCHING:
The sudden cooling of heated metal with oil, water,
or compressed air.
REACTION STRESS:
The
residual stress which could not otherwise exist if the members or parts being
welded were isolated as free bodies without connection to other parts of the
structure.
REDUCING FLAME:
See CARBONIZING FLAME.
REGULATOR:
A device used to reduce cylinder pressure to a
suitable torch working pressure.
REINFORCED WELD:
The weld metal built up above the surface of the two
abutting sheets or plates in excess of that required for the size of the weld
specified.
RESIDUAL STRESS:
Stress remaining in a structure or member as a result
of thermal and/or mechanical treatment.
RESISTANCE BRAZING:
A
brazing process in which bonding is produced by the heat obtained from
resistance to the flow of electric current in a circuit of which the workpiece
is a part, and by using a nonferrous filler metal having a melting point above
800 °F (427 °C), but below that of the base metals.
The filler metal is distributed in the joint by
capillary attraction.
RESISTANCE BUTT WELDING:
A group of resistance welding processes in which the
weld occurs simultaneously over the entire contact area of the parts being
joined.
RESISTANCE WELDING:
A
group of welding processes in which fusion is produced by heat obtained from
resistance to the flow of electric current in a circuit of which the workpiece
is a part and by the application of pressure.
REVERSE POLARITY:
The
arrangement of direct current arc welding leads in which the work is the
negative pole and the electrode is the positive pole of the welding arc.
ROCKWELL HARDNESS TEST:
In
this test a machine measures hardness by determining the depth of penetration
of a penetrator into the specimen under certain arbitrary fixed conditions of
test. The penetrator may be either a steel ball or a diamond spherocone.
ROOT:
See ROOT OF JOINT and ROOT OF WELD.
ROOT CRACK:
A crack in the weld or base metal which occurs at the
root of a weld.
ROOT EDGE:
The edge of a part to be welded which is adjacent to
the root.
ROOT FACE:
The portion of the prepared edge of a member to be
joined by a groove weld which is not beveled or grooved.
ROOT OF JOINT:
That
portion of a joint to be welded where the members approach closest to each
other. In cross section, the root of a joint may be a point, a line, or an
area.
ROOT OF WELD:
The points, as shown in cross section, at which the
bottom of the weld intersects the base metal surfaces.
ROOT OPENING:
The separation between the members to be joined at
the root of the joint.
ROOT PENETRATION:
The depth a groove weld extends into the root of a
joint measured on the centerline of the root cross section.
SCARF:
The chamfered surface of a joint.
SCARFING:
A
process for removing defects and checks which develop in the rolling of steel
billets by the use of a low velocity oxygen deseaming torch.
SEAL WELD:
A weld used primarily to obtain tightness and to
prevent leakage.
SEAM WELDING:
Welding a lengthwise seam in sheet metal either by
abutting or overlapping joints.
SELECTIVE BLOCK SEQUENCE:
A block sequence in which successive blocks are
completed in a certain order selected to create a predetermined stress
pattern.
SERIES WELDING:
A
resistance welding process in which two or more welds are made simultaneously
by a single welding transformer with the total current passing through each
weld.
SHEET SEPARATION:
In spot, seam, and projection welding, the gap
surrounding the weld between faying surfaces, after the joint has been welded.

SHIELDED WELDING:
An
arc welding process in which protection from the atmosphere is obtained through
use of a flux, decomposition of the electrode covering, or an inert gas.
SHOULDER:
See ROOT FACE.
SHRINKAGE STRESS:
See RESIDUAL STRESS.  SINGLE IMPULSE
WELDING:
The
making of spot, projection, and upset welds by a single impulse of current.
When alternating current is used, an impulse may consist of a fraction of a
cycle or a number of cycles.
SIZE OF WELD:
a.
Groove weld. The joint penetration (depth of chamfering
plus the root penetration when specified).
b.
Equal leg fillet welds. The leg length of the largest
isosceles right triangle which can be inscribed within the fillet weld cross
section.
c.
Unequal leg fillet welds. The leg length of the largest
right triangle which can be inscribed within the fillet weld cross section.
d.
Flange weld. The weld metal thickness measured at the root
of the weld.
SKIP SEQUENCE:
See WANDERING SEQUENCE.
SLAG INCLUSION:
Non-metallic solid material entrapped in the weld
metal or between the weld metal and the base metal.
SLOT WELD:
A
weld made in an elongated hole in one member of a lap or tee joint joining that
member to that portion of the surface of the other member which is exposed
through the hole. The hole may be open at one end and may be partially or
completely filled with weld metal. (A fillet welded slot should not be
construed as conforming to this definition.)
SLUGGING:
Adding
a separate piece or pieces of material in a joint before or during welding with
a resultant welded joint that does not comply with design drawing or specification
requirements.
SOLDERING:
A
group of welding processes which produce coalescence of materials by heating
them to suitable temperature and by using a filler metal having a liquidus not
exceeding 450 °C (842 °F) and below the solidus of the base materials. The
filler metal is distributed between the closely fitted surfaces of the joint by
capillary action.
SOLIDUS:
The highest temperature at which a metal or alloy is
completely solid.
SPACER STRIP:
A
metal strip or bar inserted in the root of a joint prepared for a groove weld
to serve as a backing and to maintain the root opening during welding.
SPALL:
Small
chips or fragments which are sometimes given off by electrodes during the
welding operation. This problem is especially common with heavy coated
electrodes.
SPATTER:
The metal particles expelled during arc and gas
welding which do not form a part of the weld.
SPOT WELDING:
A
resistance welding process in which fusion is produced by the heat obtained
from the resistance to the flow of electric current through the workpieces held
together under pressure by electrodes. The size and shape of the individually
formed welds are limited by the size and contour of the electrodes.
SPRAY TRANSFER:
A type of metal transfer in which molten filler metal
is propelled axially across the arc in small droplets.
STAGGERED INTERMITTENT FILLET WELD:
Two
lines of intermittent welding on a joint, such as a tee joint, wherein the
fillet increments in one line are staggered with respect to those in the other
line.
STORED ENERGY WELDING:
The
making of a weld with electrical energy accumulated electrostatically,
electromagnetically, or electrochemically at a relatively low rate and made
available at the required welding rate.
STRAIGHT POLARITY:
The
arrangement of direct current arc welding leads in which the work is the
positive pole and the electrode is the negative pole of the welding arc.
STRESS RELIEVING:
A
process of reducing internal residual stresses in a metal object by heating to
a suitable temperature and holding for a proper time at that temperature. This
treatment may he applied to relieve stresses induced by casting, quenching,
normalizing, machining, cold working, or welding.
STRING BEAD WELDING:
A
method of metal arc welding on pieces 3/4 in. (19 mm) thick or heavier in which
the weld metal is deposited in layers composed of strings of beads applied
directly to the face of the bevel.
STUD WELDING:
An
arc welding process in which fusion is produced by heating with an electric arc
drawn between a metal stud, or similar part, and the other workpiece, until the
surfaces to be joined are properly heated. They are brought together under
pressure.
SUBMERGED ARC WELDING:
An
arc welding process in which fusion is produced by heating with an electric arc
or arcs between a bare metal electrode or electrodes and the work. The welding
is shield by a blanket of granular, fusible material on the work. Pressure is
not used. Filler metal is obtained from the electrode, and sometimes from a
supplementary welding rod.
SURFACING:
The deposition of filler metal on a metal surface to
obtain desired properties or dimensions.
TACK WELD:
A weld made to hold parts of a weldment in proper
alignment until the final welds are made.
TEE JOINT:
A joint between two members located approximately at
right angles to each other in the form of a T.
TEMPER COLORS:
The colors which appear on the surface of steel
heated at low temperature in an oxidizing atmosphere.
TEMPER TIME:
In
resistance welding, that part of the postweld interval during which a current
suitable for tempering or heat treatment flows. The current can be single or
multiple impulse, with varying heat and cool intervals.
TEMPERING:
Reheating
hardened steel to some temperature below the lower critical temperature,
followed by a desired rate of cooling. The object of tempering a steel that has
been hardened by quenching is to release stresses set up, to restore some of
its ductility, and to develop toughness through the regulation or readjustment
of the embrittled structural constituents of the metal. The temperature
conditions for tempering may be selected for a given composition of steel to
obtain almost any desired combination of properties.
TENSILE STRENGTH:
The maximum load per unit of original cross-sectional
area sustained by a material during the tension test.
TENSION TEST:
A
test in which a specimen is broken by applying an increasing load to the two
ends. During the test, the elastic properties and the ultimate tensile strength
of the material are determined. After rupture, the broken specimen may be
measured for elongation and reduction of area.
THERMIT CRUCIBLE
The vessel in which the thermit reaction takes place.

THERMIT MIXTURE:
A mixture of metal oxide and finely divided aluminum
with the addition of alloying metals as required.
THERMIT MOLD:
A mold formed around the parts to be welded to
receive the molten metal.
THERMIT REACTION:
The chemical reaction between metal oxide and
aluminum which produces superheated molten metal and aluminum oxide slag.
THERMIT WELDING:
A
group of welding processes in which fusion is produced by heating with
superheated liquid metal and slag resulting from a chemical reaction between a
metal oxide and aluminum, with or without the application of pressure. Filler
metal, when used, is obtained from the liquid metal.
THROAT DEPTH:
In a
resistance welding machine, the distance from the centerline of the electrodes
or platens to the nearest point of interference for flatwork or sheets. In a
seam welding machine with a universal head, the throat depth is measured with
the machine arranged for transverse welding.
THROAT OF FILLET WELD:
a.
Theoretical. The distance from the beginning of the root of the
joint perpendicular to the hypotenuse of the largest right triangle that can be
inscribed within the fillet-weld cross section.
b.
Actual. The distance from the root of the fillet weld to
the center of its face.
TOE CRACK:
A crack in the base metal occurring at the toe of the
weld.
TOE OF THE WELD:
The junction between the face of the weld and the
base metal.
TORCH:
See CUTTING TORCH or WELDING TORCH.
TORCH BRAZING:
A
brazing process in which bonding is produced by heating with a gas flame and by
using a nonferrous filler metal having a melting point above 800 °F (427 °C),
but below that of the base metal. The filler metal is distributed in the joint
of capillary attraction.
TRANSVERSE SEAM WELDING:
The making of a seam weld in a direction essentially
at right angles to the throat depth of a seam welding machine.
TUNGSTEN ELECTRODE:
A non-filler metal electrode used in arc welding or
cutting, made principally of tungsten.
UNDERBEAD CRACK:
A crack in the heat affected zone not extending to
the surface of the base metal.
UNDERCUT:
A groove melted into the base metal adjacent to the
toe or root of a weld and left unfilled by weld metal.
UNDERCUTTING:
An undesirable crater at the edge of the weld caused
by poor weaving technique or excessive welding speed.
UPSET:
A localized increase in volume in the region of a
weld, resulting from the application of pressure.
UPSET WELDING:
A
resistance welding process in which fusion is produced simultaneously over the
entire area of abutting surfaces, or progressively along a joint, by the heat
obtained from resistance to the flow of electric current through the area of
contact of those surfaces. Pressure is applied before heating is started and is
maintained throughout the heating period.
UPSETTING FORCE:
The force exerted at the welding surfaces in flash or
upset welding.
VERTICAL POSITION:
The
position of welding in which the axis of the weld is approximately vertical. In
pipe welding, the pipe is in a vertical position and the welding is done in a
horizontal position.
WANDERING BLOCK SEQUENCE:
A
block welding sequence in which successive weld blocks are completed at random
after several starting blocks have been completed.
WANDERING SEQUENCE:
A longitudinal sequence in which the weld bead
increments are deposited at random.
WAX PATTERN:
Wax molded around the parts to be welded by a thermit
welding process to the form desired for the completed weld.
WEAVE BEAD:
A type of weld bead made with transverse
oscillation.
WEAVING:
A
technique of depositing weld metal in which the electrode is oscillated. It is
usually accomplished by a semicircular motion of the arc to the right and left
of the direction of welding. Weaving serves to increase the width of the
deposit, decreases overlap, and assists in slag formation.
WELD:
A
localized fusion of metals produced by heating to suitable temperatures.
Pressure and/or filler metal may or may not be used. The filler material has a
melting point approximately the same or below that of the base metals, but
always above 800 °F (427 °C).
WELD BEAD:
A weld deposit resulting from a pass.
WELD GAUGE:
A device designed for checking the shape and size of
welds.
WELD METAL:
That portion of a weld that has been melted during
welding.
WELD SYMBOL:
A picture used to indicate the desired type of weld.

WELDABILITY:
The capacity of a material to form a strong bond of
adherence under pressure or when solidifying from a liquid.
WELDER CERTIFICATION:
Certification in writing that a welder has produced
welds meeting prescribed standards.
WELDER PERFORMANCE QUALIFICATION:
The demonstration of a welder's ability to produce
welds meeting prescribed standards.
WELDING LEADS:
a.
Electrode lead. The electrical conductor between the
source of the arc welding current and the electrode holder.
b.
Work lead. The electrical conductor between the source of
the arc welding current and the workpiece.
WELDING PRESSURE:
The pressure exerted during the welding operation on
the parts being welded.
WELDING PROCEDURE:
The detailed methods and practices including all
joint welding procedures involved in the production of a weldment.
WELDING ROD:
Filler
metal in wire or rod form, used in gas welding and brazing processes and in
those arc welding processes in which the electrode does not provide the filler
metal.
WELDING SYMBOL:
The
assembled symbol consists of the following eight elements, or such of these as
are necessary: reference line, arrow, basic weld symbols, dimension and other
data, supplementary symbols, finish symbols, tail, specification, process, or
other references.
WELDING TECHNIQUE:
The
details of a manual, machine, or semiautomatic welding operation which, within
the limitations of the prescribed joint welding procedure, are controlled by
the welder or welding operator.
WELDING TIP:
The tip of a gas torch especially adapted to
welding.
WELDING TORCH:
A device used in gas welding and torch brazing for
mixing and controlling the flow of gases.
WELDING TRANSFORMER:
A device for providing current of the desired
voltage.
WELDMENT:
An assembly whose component parts are formed by
welding.
WIRE FEED SPEED:
The rate of speed in mm/sec or in./min at which a
filler metal is consumed in arc welding or thermal spraying.
WORK LEAD:
The electric conductor (cable) between the source of
arc welding current and the workpiece.
X-RAY:
A radiographic test method used to detect internal
defects in a weld.
YIELD POINT:
The
yield point is the load per unit area value at which a marked increase in
deformation of the specimen occurs with little or no increase of load; in other
words, the yield point is the stress at which a marked increase in strain
occurs with little or no increase in stress.

APPENDIX2. КЛАССИФИКАЦИЯ ВИДОВ И СПОСОБОВ СВАРКИ

Таблица 1. Классификация сварки металлов по ГОСТ
19521-74

Класс сварки

Определение

Вид сварки

Термический

Виды сварки, осуществляемы
  плавлением с использованием тепловой энергии

дуговая, электрошлаковая,
  электронно-лучевая, плазменно-лучевая, ионно-лучевая, тлеющим разрядом,
световая, индукционная, газовая, термитная,
  литейная.

Термомеханический

Виды
  сварки, осуществляемые с использованием тепловой энергии и давления

контактная, диффузионная,
  индукционнопрессовая, газопрессовая, термокомпрессионная, дугопрессовая,
  шлакопрессовая,

термитно-прессовая, печная

Механический

Виды
  сварки, осуществляе мые с использованием ме ханической энергии и дав ления

холодная, взрывом, ультразвуковая, трением,
  магнитноимпульсная.

Таблица 2. Термины и определение
сварочных материалов по ГОСТ 2601-84

Термин

Определение

Сварочная проволока

Проволока для использования
  в качестве плавящегося электрода либо присадочного металла при сварке
  плавлением

Электродная проволока

Сварочная проволока для использования в качестве
  плавящегося электрода

Присадочная проволока

Сварочная проволока,
  используемая как присадочный металл и не являющаяся электродом

Самозащитная проволока

Электродная проволока,
  содержащая вещества, которые защищают расплавленный металл от вредного
  воздействия воздуха при сварке

Порошковая проволока

Сварочная проволока,
  состоящая из металлической оболочки, заполненной порошкообразными веществами

Неплавящийся электрод для
  дуговой сварки

Деталь
  из электропроводного материала, включаемая в цепь сварочного тока для подвода
  его к сварочной дуге и не расплавляющаяся при сварке

Плавящийся электрод для
  дуговой сварки

Металлический
  электрод, включаемый в цепь сварочного тока для подвода его к сварочной дуге,
  расплавляющийся при сварке и служащий присадочным металлом

Покрытый электрод

Плавящийся
  электрод для дуговой сварки, имеющий на поверхности покрытие, адгезионно связанное
  с металлом электрода

Покрытие электрода

Смесь веществ, нанесенная
  на электрод для усиления ионизации, защиты от вредного воздействия среды,
  металлургической обработки сварочной ванны

Таблица 3. Сварные соединения и швы

Сварное соединение

неразъемное соединение, выполненное сваркой

Стыковое соединение

двух элементов, примыкающих
  друг к другу торцевыми поверхностями

Угловое соединение

двух элементов, расположенных под углом и сваренных в месте
  примыкания их краев

Нахлесточное соединение

в котором сваренные
  элементы расположены параллельно и частично перекрывают друг друга

Тавровое соединение

в котором торец одного
  элемента примыкает под углом и  приварен к боковой поверхности другого
  элемента

Торцевое соединение

в котором боковые
  поверхности     сваренных элементов примыкают друг к другу

Сварная конструкция

металлическая  конструкция, изготовленная сваркой отдельных
  деталей

Сварной узел

часть конструкции, в
  которой сварены примыкающие друг к другу элементы

Сварной шов

участок сварного
  соединения, образовавшийся в результате кристаллизации расплавленного металла
  или пластической деформации при сварке давлением или сочетания кристаллизации
  и деформации

Проход при сварке

однократное перемещение в одном направлении источника
  теплоты при сварке и (или) наплавке

Основной металл

Металл подвергающихся
  сварке соединяемых           частей

Глубина проплавления

Наибольшая
  глубина расплавления основного  металла в сечении шва или наплавленного
  валика

Сварочная ванна

Часть металла свариваемого шва, находящаяся при сварке
  плавлением в жидком состоянии

Присадочный металл

Металл для введения в сварочную ванну в

дополнение          к        расплавленному
           основному металлу

Наплавленный металл

Переплавленный присадочный
  металл, введенный в сварочную ванну или
наплавленный на основной
  металл

Металл шва

Сплав, образованный
  расплавленным основным и       наплавленным     металлами  или    только           переплавленным
  основным металлом

Угар при сварке

Потери металла на испарение
  и окисление при сварке

Свариваемость

Металлический
  материал считается поддающимся сварке до установленной степени при данных
  процессах и для данной цели, когда сваркой достигается металлическая
  целостность при соответствующем технологическом процессе, чтобы свариваемые
  детали отвечали техническим требованиям как в отношении их собственных
  качеств, так и в отношении их влияния на конструкцию,которую они образуют

Сварочный флюс

Материал,
  используемый при сварке для химической очистки соединяемых поверхностей и
  улучшения качества шва

Флюс для дуговой сварки

Сварочный флюс, защищающий
  дугу и           сварочную ванну от вредного воздействия окружающей среды

REFERENCES

1.       ASM
International (2003). Trends in Welding Research. Materials Park, Ohio: ASM
International. - ISBN 0871707802
2.       Assessment
of Exposure to Fume from Welding and Allied Processes, HSE Books, 1990.
3.       Blunt,
Jane and Nigel C. Balchin (2002). Health and Safety in Welding and Allied
Processes. Cambridge: Woodhead. - ISBN 1855735385

4.       Brightmore
A. D., Bernasek M. Moving Weld Management from the Desk to the Desktopю Using
"expert" software packages, computers can make life easier for the
welding engineer. - http://www.cspec.com/csp-paper.htm1.
5.       Canadian
Welding Association. - http://www.cwa-acs.org
6.       Cary,
Howard B. and Scott C. Helzer (2005). Modern Welding Technology. Upper Saddle
River, New Jersey: Pearson Education. - ISBN 0131130295
7.       Kalpakjian,
Serope and Steven R. Schmid (2001). Manufacturing
Engineering and Technology. Prentice Hall.- ISBN 0201361310.
8.       Klingensmith,
S., J. N. DuPont and A. R. Marder, Welding Journal, 84 (2005) 77s-85s.
9.       Hicks,
John (1999). Welded Joint Design. New York: Industrial Press. - ISBN
0831131306.
10.   Lincoln
Electric (1994). The Procedure Handbook of Arc Welding. Cleveland: Lincoln
Electric. - ISBN 9994925822.
11.   Modern Welding
by Althouse, Turnquist, and Bowditch. The GoodheartWillcox Co. 1970
12.   Robot welding.
- http://www.robot-welding.com
13.   The American
Welding Society. - http://www.aws.org

14.   The Control of
Exposure to Fume from Welding, Brazing and Similar Processes, HSE Books, 1990.

15.   The Welding
Encylopedia, The Welding Engineer staff, ninth ed. 1938
16.   The Welding
Institute. - http://www.twi.co.uk
17.   Weman, Klas
(2003). Welding processes handbook. New York: CRC Press LLC. - ISBN
0849317738.
18.   Welding in
Space. - http://www.thefabricator.com/Articles/Welding_Article.cfm?ID=553

19.   Welding
Handbook Vol. 2 Library of Congress number 90-085465   copyright 1991 by
American Welding Society

20.   Welding
handbook Volume 2, eighth edition.''  Library of Congress number: 90-085465
copyright 1991 by American Welding Society Occupation Exposure Limits, HSE
Books.
21.   Технология
электрической сварки плавлением / Под. ред.
Е.Е.Патона. – М.: Государственное научно-техническое
издательство машиностроительной литературы. – 664 с.
22.   Хромченко Ф.А.
Сварочное пособие электросварщика. – М.: Машиностроение, 2003. – 420 с.

NOTES NOTES Сергей Владимирович Гричин

АНГЛИЙСКИЙ ДЛЯ
СВАРЩИКОВ

Учебное
пособие

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         Корректор
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file_name: Методическое пособие по английскому для студентов СПО 1 курса по специальности_ сварщик.pdf

alt: ФЕДЕРАЛЬНОЕ АГЕНТСТВО ПО ОБРАЗОВАНИЮ

alt: УДК 811 (Англ.) ББК 81 (Англ

alt: PART 1. JOB DESCRIPTION AND WELDING

alt: Text 3. Man-machine Communication for

alt: Reading Pre-reading

alt: Look through the last paragraph of the text and say, what exactly, in your opinion, the following welding specialists do: welder welding machine operator welding…

alt: Vocabulary journeyman (person) наемный квалифицированный рабочий apprentice ученик plate working обработка листового металла blueprint 1) делать светокопию, копировать чертеж 2) делать разметку brazing пайка твердым…

alt: What Preparation and Training

alt: Wage Rate • as an apprentice you would start at a wage rate less than that of a journeyperson • this rate increases gradually as…

alt: ASME сокр. от American

alt: Welding Fundamentals

alt: Magnetic Particle & Liquid

alt: Reading Text 5. Taking the

alt: Translate the following sentences into

alt: Vocabulary joining, joint соединение, связь, сращивание, шов armour броня carburization науглероживание brittle хрупкий, ломкий interlayering чередование слоев high-carbon высокоуглеродистый hammer forging свободная ковка на молоте…

alt: Text 2. From the History of Welding

alt: What was the quality of the welds produced by the arc welding using bare wires like? 2

alt: Reading Text 3. Welding's Vital

alt: During this same period, Kaiser

alt: Vocabulary soldering пайка; пайка мягким (легкоплавким) припоем tinning лужение; облуживание leading свинцевание brazing 1) пайка твердым припоем (из меди и цинка) 2) покрытие медью sweat…

alt: MIG (Metal Inert Gas): A DC arc welding process which uses filler metal fed in the form of a spool of thin wire, shielded by…

alt: Find the English equivalents for the following words and word combinations: источник тепла, расплавленный металл, необходимый размер, сварной шов, не нагретый металл, механические свойства, максимум…

alt: A weld can be defined as a coalescence of metals produced by heating to a suitable temperature with or without the application of pressure, and…

intro:
Методичка составлена специально для предмета "Иностранный язык в профессиональной деятельности" и "Иностранный язык" для студентов направления Сварочное Производство среднего профессионального образования
Содержит
Лексические и грамматические упражнения на соответствующие специальности темы
Прошла успешную апробацию на студентах первого курса

title: Методическое пособие по английскому для студентов СПО 1 курса по специальности: сварщик