The document provides information about welding from a presentation given by Surendra Kumar. It discusses different types of welding including gas welding, arc welding, and their advantages and limitations. Gas welding uses oxygen and acetylene to produce a flame and includes oxy-acetylene welding. Arc welding uses an electric arc between an electrode and base metal to produce heat. Common applications of welding include automobile, aircraft, machinery manufacturing and structural/ship building. In conclusion, welding is widely used in industries to join metals and provides design flexibility at a relatively low cost.

2. A Vocational Training
Presentation
on
“Welding”
From
“SIMPLEX CASTING LTD. (UNIT-III)”
BY
SURENDRA KUMAR
(Department Of Mechanical Engineering)

3. SIMPLEX CASTING Ltd
UNIT-III
223/2,224 TEDESARA,INDUSTURIAL,MUDIPAR ROAD
 INTRODUCTION
It is a fabrication department of simplex or
deportment of production. Internal planning for
sequence of manufacturing of the job. Then cutting
and fitting and welding then finishing

4. Contents:
Welding
Types of Welding
Gas Welding(Oxy- Acetylene)
Arc Welding(Metal Arc)
Merits & Limitations of Welding Process
Application
Conclusion

5. Welding:
The Welding is a process of joining two or more,
similar or dissimilar metals by heating them to a
suitable temperature , with or without the
application of pressure, filler materials and flux.
Welding is used for making permanent
joints.

6. TYPES OF WELDING :
 Plastic Welding or Pressure Welding:
The piece of metal to be joined are heated to a plastic
state and forced together by external pressure
(Ex) -Resistance welding
 Fusion Welding or Non-Pressure Welding:
The material at the joint is heated to a molten state and
allowed to solidify
(Ex)- Gas welding, Arc welding

7. CLASSIFICATION OF WELDING PROCESSES:
Gas welding(Oxy- Acetylene)
Arc welding(Metal Arc)
Resistance welding
Solid state welding
Thermo-chemical welding
Low Temperature welding

8. Gas Welding:
Gas Welding is a fusion welding process, in which the
heat for welding is obtained by the combustion of
oxygen and fuel the gas may be acetylene ,hydrogen or
propene .
Types:
• Oxy- Acetylene
• Air-Acetylene
• Oxy-Hydrogen
• Oxy-Fuel

9. Oxy-Acetylene Welding:
When a combination of
Oxygen and acetylene is
used in correct
proportions to produce an
Intense gas flame, the
process is known as
oxy-acetylene welding.

10. Gas Welding Equipment :
1. Gas Cylinders
Pressure-
Oxygen – 125 kg/cm2
Acetylene – 16 kg/cm2
2. Regulators
• Working pressure of oxygen 1 kg/cm2
• Working pressure of acetylene 0.15 kg/cm2
• Working pressure varies depends upon the thickness of the work pieces
welded.
3. Pressure Gauges
4. Hoses
5. Welding torch
6. Check valve
7. Non return valve

11. Advantages:
 Portable and most versatile process.
 Better control over the temperature.
 Suitable to weld dissimilar matter.
 Low cost & maintenance.
Disadvantages:
 Not suitable for heavy section.
 Less working temperature of gas flame.
 Slow rate of heating.

12. Arc Welding:
“Arc welding is a fusion welding process in which the
heat required to fuse the metal is obtain from the
electric arc between the base metal and an electrode.
Types:
1. Metal Arc Welding
2. Submerged Arc Welding
3. Tungsten Inert Gas Welding
4. Metal Inert Gas Welding

13. Equipment:
A welding generator (D.C.) or Transformer (A.C.)
Two cables- one for work and one for electrode
Electrode holder
Electrode
Protective shield
Gloves
Wire brush
Chipping hammer
Goggles

14. Metal Arc Welding :
Uses an electric arc to
coalesce metals
Arc welding is the most
common method of
welding metals
Electricity travels from
electrode to base metal
to ground

15. Advantages and Disadvantages of Arc Welding
Advantages
 Most efficient way to join
metals
 Lowest-cost joining
method
 Affords lighter weight
through better utilization
of materials
 Joins all commercial
metals
 Provides design flexibility
Disadvantages
 Manually applied,
therefore high labor cost.
 Need high energy causing
danger
 Not convenient for
disassembly.
 Defects are hard to detect
at joints.

16. Applications:
It is used in the manufacture of automobile
bodies.
Aircraft Frames
Railway Wagons
Machine Frames
Structural works, tanks, furniture, boilers,
general repair work and ship building etc.

17. Conclusion:
In these we learn about most popular welding
type uses in industries.
A good weld is always strong.
General welding equipment is not very costly.
 Portable welding equipment are available.
A large number of metal and alloy both similar and
dissimilar can be join by welding.
Welding permits considerable freedom in design.