The document discusses arc welding, including its basics and principles. Arc welding involves striking an electric arc between an electrode and the metal workpiece to melt and join the metals. The key steps are preparing the materials, selecting the welding process and filler material, assessing safety requirements, and inspecting the final weld. Arc welding is commonly used in construction and fabrication due its portability, low equipment cost, and ability to weld steels and other alloys.

1. ARC WELDING

2. TEAM MEMBERS
Indal Patel
Anshita Agrawal

3. WELDING
1. Process in which two (or more) parts are coalesced
at their contacting surfaces by application of:
 Heat and pressure
 Some welding processes use a filler material
added to facilitate coalescence

4. WHAT IS ARC WELDING?
• The fusing of two or more pieces of metal together by
using the heat produced from an electric arc welding
machine.

5. BASICS OF ARC WELDING
• The arc is struck between the electrode and
the metal. It then heats the metal to a melting
point. The electrode is then removed,
breaking the arc between the electrode and
the metal. This allows the molten metal to
“freeze” or solidify.

6. HOW AN ARC IS FORMED?
• The arc is like a flame of
intense heat that is
generated as the electrical
current passes through a
highly resistant air gap.

8. 8
BASIC STEPS OF ARC WELDING
• Prepare the base materials: remove paint and rust
• Choose the right welding process
• Choose the right filler material
• Assess and comply with safety requirements
• Use proper welding techniques and be sure to protect the
molten puddle from contaminants in the air
• Inspect the weld

9. PRINCIPLE OF ARC
• A suitable gap is kept between the work and electrode
• A high current is passed through the circuit.
• The electric energy is converted into heat energy, producing a
temperature of 3000°C to 4000°C.
• This heat melts the edges to be welded and molten pool is
formed.
• On solidification the welding joint is obtained

10. USES OF ARC WELDING
• Many things around us are welded …
• Pipelines that bring fresh water
• Towers that carry electricity to houses
• Cars and buses that take people where they need to go
• Arc welding continues to be used extensively in the construction of steel structures and
in industrial fabrication.
• The process is used primarily to weld iron and steels (including stainless steel) but
aluminium, nickel and copper alloys can also be welded with this method.
• It dominates other welding processes in the maintenance and repair industry, and though
flux-cored arc welding is growing in popularity
• Is popular because it can be used in the field without complicated equipment and gases

12. WELDING POSITIONS As well as flat
and horizontal
Vertical Overhead

13. ELECTRIC ARC WELDING

14. ELECTRIC POWER FOR WELDING
• Current used may be
• 1. AC
• 2. DC
For most purposes, DC is preferred.

15. AC ARC WELDING
• instead of 220 V at 50 A, for example,
the power supplied by the transformer
is around 17–45 V at currents up to
600 A.

16. DC ARC WELDING
• D.C. machines are made up to the capacity range of 600 amperes.
• 45 to 95 volts
• D.C. can be given in two ways:
(a) Straight polarity
(b) Reverse polarity
The polarity will affect the weld size and application

17. ARC WELDING EQUIPMENTS

18. ADVANTAGES OF ARC WELDING
• 1. Simple welding equipment
• 2. Portable
• 3. Inexpensive power source
• 4. Relatively inexpensive equipment
• 5. Welders use standard domestic current.
• 6. Process is fast and reliable
• 7. Short learning curve
• 8. Equipment can be used for multiple functions
• 9. Electric arc is about 5,000 oC
• 10. Used for maintenance, repair, and field construction

19. DISADVANTAGES
• Not clean enough for reactive metals such as
aluminium and titanium.
• The deposition rate is limited because the electrode
covering tends to overheat and fall off.
• The electrode length is ~ 35 mm and requires electrode
changing lower the overall production rate.

20. •Thank You