ELECTRIC ARC WELDING:

Presentation by

Syed Waseem Haider

OUTLINE:

What is arc welding? Can we join two different metal parts?Components of arc weldingWhen welding not allowed? Importance of arc welding Successful welding Safety

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.

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.

Components of arc welding:

Work piece or base metalElectrodeElectrode holderElectrode lead(cable)Welding tableWork peace Lead(cable)Plug to power sourceInput power lead(cable)

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

Importance Of Welding?

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

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

Average Thickness of Plate orSection

Maximum RecommendedElectrode Diameter

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

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.

Electrode Size(mm)

ElectrodeLength (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)

Correct Travel Speed:The electrode should be moved along in the direction of the joint being welded.

Correct preparation of work to be welded:Correct equipmentCorrect method

Correct angle of electrode to work:Angle should not be 90

Arc Welding Safety:

Some potential hazards are given below.

Arc raysNoiseElectric shockFumes and gasesProtective clothes

Arc rays:

Welding arc is brighter than the sun, so it can harm your eye siteIt can even burn your eyes and skinGlasses can save your eye site

Noise:

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

Electric shock:

Electric shock can even kill you, so dont touch any live electric parts

Must insulate yourself by protective clothes

Fumes and gases:

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

Protective clothes:

Clothes can protect you from raysInsulate yourself by wearing clothes, so no fear of shock

THIS INCLUDES THE PRESENTATION