Page 184 - CITS - Fitter Trade Pactical - Volume - 2

FITTER - CITS

EXERCISE 52 : Depositing bead on aluminium sheet 2mm
thick - position flat

Objectives

At the end of this exercise you shall be able to
• weld fusion runs with filler wire on aluminimum by TIG welding process in flat position.

Job Sequence

1 Prepare the aluminimum sheet as per dimensions.
2 Clean the surface with the stainless steel wire brush.
3 Also do the chemical cleaning with acetone/alcohol to remove the grease and surface oxide.

4 Draw parallel lines and punch the lines as per dimensions.
5 Set the job in flat position.
6 Select the power supply as follows:
– In case of helium as shielding gas use DCEN.

– In case of Argon as shielding gas and use AC power source. Majority of welding is done using argon gas.
7 Set up the GTA welding plant as per the Fig.1.
8 Select the type and size of tungsten electrode, current, gas flow rate and set them on the machine.
9 Select aluminium filler wire. 1.6mmf with 5% silicon.
10 Switch on the machine and strike the arc.

11 Deposit fusion run with filler wire using leftward welding technique.
12 Clean and inspect the weld job.

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