Page 272 - CITS - Welder - Trade Practical

WELDER - CITS

• Select the various parameters and set them accordingly.
• Weld the joint in flat position using leftward techniques.

Fill the crater
• Clean the weld area thoroughly.
• Inspect the job for free from defects.
Visual inspection : Slight convexity, uniform width, uniform ripples and free from under cut at the toes of the
weld indicate a smooth.
Skill Sequence

Construct Square butt joint on Aluminum sheet 2 mm
thick in Horizontal & Vertical positions by GTAW

Objectives: At the end of this exercise you shall be able to
• construct Square butt joint on Aluminum sheet 2 mm thick in Horizontal positions by GTAW.

Setting and tacking the lap joint
Set the butt joint with an overlap of 25mm.
The overlap may vary based on the plate thickness.
Tack-weld on both ends. Ensure the 2 lapping sur-faces are perfectly cleaned and they contact each other
properly. Use a ∅ 2.4 Tungsten electrode with 160-amp current for tacking.
Set the joint in a Horizontal & vertical position using angle iron.
Welding the Butt fillet joint in flat position

Deposit root run with 100-110 amp current.
Maintain 80° angle to the line of the weld and 45° between the weld faces.
Maintain a short arc to get uniform fusion and root penetration.

Avoid side-to-side movement of the electrode.
Deslag and clean the root bead thoroughly.
Deposit the final covering run 160 amp current.
Give side-to-side movement to the electrode not more than 2.5 times its dia.
Use the same electrode angle as was used for the root bead.

Prevent the upper edge of the plate from melting off by not allowing the arc to concentrate more on the upper
edge.
Remove the slag with a chipping hammer.

Clean the weld with a steel wire brush.
Inspect the Butt fillet weld and ensure :
- It has equal leg length with slight convexity.
- The upper edge of the plate has not melted off.

- It is free from surface

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CITS : C G & M - Welder - Exercise 68