Electric arc welding involves melting metal parts together at points of contact using an electric arc. It can only join parts made of the same metal. The process requires a workpiece, electrode, electrode holder, cables, welding table, and a power source. Welding should not occur below 25°C or above 70% humidity to prevent cracks and rust. Arc welding is important for infrastructure like pipes, vehicles, electricity towers, and tanks. Successful welding depends on selecting the correct welding current and electrode size for the material thickness, as well as proper travel speed, workpiece preparation, electrode angle, and safety equipment like glasses, ear protection, protective clothing, and ventilation.

1. ELECTRIC ARC WELDING:
Presentation by
Syed Waseem Haider

2. OUTLINE:
 What is arc welding?
 Can we join two different metal
parts?
Components of arc welding
When welding not allowed?
 Importance of arc welding
 Successful welding
 Safety

3. What Is Electric Arc Welding?
Arc welding is the process by which two
metal parts are joined by melting the parts
at the points of contact.

4. Can We Join Two Different Metal Parts?
NO…………
Because Metal parts should be the same.
If not then the one part will melt slowly
rapidly than the other one.

5. Components of arc welding:
Work piece or base metal
Electrode
Electrode holder
Electrode lead(cable)
Welding table
Work peace Lead(cable)
Plug to power source
Input power lead(cable)

7. When welding not allowed?
If temperature is below 25 degree c and
Humidity is above 70%, then welding will
be not allowed.
Cracks and rust will take place

8. Importance Of Welding?
Welding is using in different ways….
Water supply(Pipe lines)
Traveling(cars, buses etc)
Electricity supply(Towers)
Defence(Tanks etc)

9. Successful welding?
Successful welding depends on the
following factors:
Correct welding current:
Correct current selection for a
particular job is an important factor in
arc welding.
Electrode Size (mm)
Current Range (Amp)
2.5
65 to 90
3.2
110 to 130
4.0
140 to 165
5.0
170 to 260

10. Electrodes Size:
The size of the electrode generally
depends on the thickness of the section
being welded, and the thicker the section
the larger the electrode required.
Average Thickness of Plate Maximum Recommended
or
Electrode Diameter
Section
1.5 to 2.0 mm
2.5 mm
2.0 to 5.0 mm
3.2 mm
5.0 to 8.0 mm
4.0 mm

11. Correct Travel Speed:
The electrode should be moved along in
the direction of the joint being welded.
Electrode Size
(mm)
Electrode
Length (mm)
Run Length
(mm)
4.0
350
175(min) and
300(max)
3.2
350
125(min) and
225(max)
2.5
350
100(min) and
225(max)

12. Correct preparation of work to
be welded:
Correct equipment
Correct method
Correct angle of electrode to
work:
Angle should not be 90

13. Arc Welding Safety:
Some potential hazards are given below.
Arc rays
Noise
Electric shock
Fumes and gases
Protective clothes

14. Arc rays:
Welding arc is brighter than the sun, so it
can harm your eye site
It can even burn your eyes and skin
Glasses can save your eye site

15. Noise:
Loud noise can harm your hearing capability.
Noise can be controlled by using ear plugs
and air muffs.

16. Electric shock:
Electric shock can even kill you, so dont
touch any live electric parts
Must insulate yourself by protective clothes

17. Fumes and gases:
Fumes and gases can harm you.
Ventilation must be there in the welding
room, so that fumes and gases can exhaust
outside
Keep your head out of the range of
dangerous gases

18. Protective clothes:
Clothes can protect you from rays
Insulate yourself by wearing clothes, so no
fear of shock

19. THIS INCLUDES THE PRESENTATION