Page 152 - CITS - Welder - Trade Practical

WELDER - CITS

Skill Sequence

• Tack-weld both ends of the job by applying cast iron flux and using a C.I. filler rod with 2 mm root gap.
• Keep the inner cone of the flame at about 3 to 4 mm away from the molten metal.
• Give a slight weaving motion to the blowpipe but not to the filler rod.
• Weld the root run ensuring penetration and fill the crater

• Clean the root run thoroughly
• Play the flame again on the job and preheat to dull red colour
• Deposit a second layer over the root run by manipulate in the blowpipe and filler rod in the same manner as
done earlier.

• Stop at the finishing point at the left, fill the crater and complete the weld.
• Heat the job again and cover the job by ash or dry sand and allow it to cool slowly
• Clean the joint and inspect for weld defects like cracks, undercut, poor weld profile, weld reinforcement, blow-
hole, porosity etc.
Check and ensure the correct size of the cast iron pieces.
Clean the surfaces of the job pieces thoroughly before welding.
Bevel the edges at an angle of 45” by grinding or by machining with about 2 mm root face as shown in the figure
2. Avoid feather edges and round off the sharp edges.
Keep the job pieces on the fire-brick and set a root gap of 2 mm to 3 mm.
Select nozzle No. 10 and adjust a perfect neutral flame. Preheat the job to a dull red colour (about 540°C) by
playing the flame over the entire plate surfaces.
Use the temperature sticks to check the temperature.
Tack-weld at both ends of the joint by using a 6 mm super silicon cast iron rod with cast iron flux
Weld the root run (first layer) by holding the blowpipe at an angle of 60° to 70° and the filler rod 40° to 50” in
leftward technique (forehand technique).

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CITS : C G & M - Welder - Exercise 44