Page 71 - CITS - Welder - Trade Practical

WELDER - CITS

Open corner joint on MS plate 10mm thick in vertical
position (SMAW)

Objectives: At the end of this exercise you shall be able to
• weld root run on open corner joint in vertical upward
• deposit 2nd and 3rd layer by weaving motion on open corner joint in vertical upward
• clean and inspect for surface defects and angle between the members.

Job Sequence

• Mark the plate to size and gas cut as per drawing.
• Prepare square edges and clean the parts to be welded.
• Set the 2 pieces as an open corner joint and use spacers to maintain a uniform root gap of 1.5 to 2mm. Then
tack weld the two pieces together to form an 87° angle between the inner faces of the plates.
• Remove the spacers and set or fix the weldment in vertical position on the weld positioner.
• Select 3.15ø electrode and set 110 Amps DCEP.
• Deposit root run with short arc length.
• Deslag and clean thoroughly with a wire brush.

Note: Use goggle while deslagging.
• Select 4mmø electrode and set 160 amps.
• Deposit 2nd run using short arc and slight weaving motion.
• Deslag and deposit third and final run with 4mm dia electrode.

• Avoid undercut.
• Clean the joint and inspect for defects.

Skill Sequence

Open corner joint on MS plate of 10mm thick in vertical

position

Objectives: At the end of this exercise you shall be able to
• prepare and weld open corner joint on MS plate of 10mm thick in vertical position.

Setting and tacking of the fillet open corner joint
Mark and punch the plates, to cut square by gas cutting.
Grind or file the gas-cut edges to square.

Remove the grinding burrs and clean the surfaces by filing and with a wire brush.
Note: Wear goggles while cutting, grinding.
Set the fillet open corner joint with a 1.5 to 2mm root gap and an angle of 87° between the inside surfaces of the
plates to control the distortion. Fig1.
Tack-weld on the root side of the joint on both ends.
Use a 3.15 mm dia. M.S. electrode and 110 amps current.
Position the joint in vertical and the angle of the line of weld with the top of the table should be 90°. (Fig 1)

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CITS : C G & M - Welder - Exercise 10