PowerPoint to accompany
Welding
Principles and Practices
Third Edition
Sacks and Bohnart
History of
Welding
Chapter 1
1
Copyright © The McGraw-Hill Companies, Inc.
Permission required for reproduction or display.
What is Welding?
• Break into groups and discuss what you think
welding is
• Can you think of types of welding?
1-2
Overview
• Welding is joining two pieces of metal by:
– Heating to temperature high enough to cause
softening or melting
– With or without application of pressure
– With or without use of filler metal
• Usually best method to use when fastening metal
1-3
Uses of Welding
• Constructing and manufacturing:
1-4
History of Metalworking
• Welding began more than 3000 years ago
– Hot or cold metals hammered to obtain forge weld
1-5
History of Metalworking
• Bronze developed between 3000 and 2000 B.C.
• Iron became known to Europe about 1000 B.C.
– Several thousand years after use of copper
– Replaced bronze as metal used in manufacture of
utensils, armor and other applications after 800 B.C.
1-6
History of Metalworking
• Working of metals followed one another in
great ancient civilizations
– From copper, to bronze, silver, gold, and iron
1-7
Early Developments in Welding
• Edmund Davy discovered acetylene at beginning
of nineteenth century = Oxy- Acetylene
• Sir Humphrey Davy discovered the electric arc
in 1801 = Arc Welding
– Concerned with use of arc for illumination
These inventions were forerunner of
– Demonstrated possible to maintain high voltage arc
present arc welding process.
for varying periods of time by 1809
• Workable electrical generating devices invented
and developed on practical basis by 1850
1-8
History of Metalworking
• first commercial oxyacetylene welding torch at
turn of the century
• Electric arc welding method used in US until
about 1920
– Handicapped because of welds produced by these
bare electrodes not as strong as metal being welded
• Welding arc very unstable
• No Flux
1-9
History of Metalworking
• Technology of welding progressed slowly until
World War I
– Demands of war called for improved methods of
fabrication
– End of war, welding widely accepted
• Research on coated electrodes through 1920s
resulted in electrode coatings and improved
core wire
1 - 10
Multipass Welds
Pass 1
Ability to make multipass welds
such as this one, on plate and pipe,
led to growth of industry. Welds are
sound and have uniform appearance.
Pass 2
Pass 3
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1 - 11
History of Metalworking
• Stick welding process
– Advanced rapidly due to electrode coatings and
improved core wire
– Now called shielded metal arc welding (SMAW)
– Uses 14” stick electrode that conducts current from
holder to work
– Arc melts electrode, creating weld
Stick welding
1 - 12
Tungsten Inert Gas (TIG) Process
An aluminum weld made using
the TIG process. The welding
of aluminum is no longer a
problem and can be done with
the same ease as that of steel.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1 - 13
GMAW (metal inert gas: MIG)
Process
• Concentrates high heat at a focal point
• Produces
–
–
–
–
Small heat-affected zone
Narrow bead width
Deep penetration
Faster welding
speed
Responsible for over
70 percent of welds
being performed today.
• Now used in all
industries
St Louis Car. Co.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1 - 14
Industry Demand
• Over 90 welding processes
• Force new and improved developments in
machines, gases, torches, electrodes,
procedures, and technology
• Constant research for new metals done by
shipbuilding, space and nuclear industries
– Needs Spur research in welding
1 - 15
Welding Associations
• American National Standards Institute (ANSI)
• American Petroleum Institute (API)
• American Society of Mechanical Engineers
(ASME)
• American Welding Society (AWS)
• American Bureau of Shipping (ABS)
Provide guidance and standards relating
to the welding industry.
1 - 16
Resistance Welding
• Includes spot welding, seam welding, and other
similar processes performed on machines
• Operators usually taught on job
– Semiskilled workers do not need specific hands-onwelding skills
1 - 17
Arc and Gas Welding
• Welders have almost complete control of the
process
– Must know properties of metals to weld; which
weld process to use; and how to plan, measure, and
fabricate
1 - 18
Welding Positions
Overhead
Vertical
General Electric Corp.
As well as flat
and horizontal
Miller Electric Mfg. Co.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1 - 19
Weld Positions
1 - 20
Qualifications and Personal
Characteristics
• Welders certified for ability to do their work
and have work pass inspection.
• Required to pass periodic qualification tests
• Certifications issued according to kind and
gauge of metal and specific welding process
• Can hold several different certifications
simultaneously
1 - 21
Example of Magnetic-Particle
Testing in Building
Weld testing and
inspection give
proof of the
soundness of welds.
Circlesafe Aerosol/Circle Systems, Inc.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1 - 22
Master Welder Job Examples
Welds in these tanks must
meet X-ray requirements
and pass a dye penetrant
test. Tanks are often lined
with a very thin layer of
pure silver.
Nooter Corp
Creating Art!
Enrique Vega
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
1 - 23
Master Welder
• Master craftsperson
• Able to weld all steels and alloys
– Plus nickel, aluminum, titanium, zirconium, and
their alloys and claddings
• Welds of highest quality
• Welds meet requirement of job
– Delicate welding of silver and gold
– Heavy pressure vessels requiring 4-inch plate
1 - 24
Welding Occupations Requiring
a High School Education
•
•
•
•
•
•
•
•
Welding operator
Welding fitter
Combination welder
Master welder
Welding supervisor
Welding analyst
Inspector
Welding foreman
•
•
•
•
•
•
•
Welding superintendent
Equipment sales
Sales demonstrator
Sales troubleshooter
Welding instructor
Robotics welder operator
Jog or fabrication shop
owner
1 - 25
Welding Occupations Requiring
a College Education
• Welding engineer
(metallurgical)
• Welding development
engineer
• Welding research
engineer
• Technical editor
• Welding professor
• Certified welding inspector
(AWS/CWI)
• Corporation executive
• Owner of welding business
• Sales engineer
1 - 26
So... What is welding?
• Alright so now what is welding?
1 - 27