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9.04 Stick Welding Problems
Description
1 Gas pockets or voids in
weld metal (Porosity).
2 Crack occurring in weld
metal soon after
solidification
commences.
3 A gap is left by failure of
the weld metal to fill the
root of the weld.
4 Portions of the weld run
do not fuse to the
surface of the metal or
edge of the joint.
Possible Cause
A
Electrodes are damp.
B
Welding current is too high.
C
Surface impurities such as oil,
grease, paint, etc.
A
Rigidity of joint.
B
Insufficient throat thickness.
C
Cooling rate is too high.
A
Welding current is too low.
B
Electrode too large for joint.
C
Insufficient gap.
D Incorrect sequence.
Figure 9. Example of Insufficient Gap or Incorrect Sequence
A
Small electrodes used on heavy cold
plate.
B
Welding current is too low.
C Wrong electrode angle.
D Travel speed of electrode is too
high.
E Scale or dirt on joint surface.
Figure 10. Example of Lack of Fusion
43
Remedy
A
Dry electrodes before use.
B
Reduce welding current.
C
Clean joint before welding.
A
Redesign to relieve weld joint of
severe stresses or use crack
resistance electrodes.
B
Travel slightly slower to allow greater
build up in throat.
C
Preheat plate and cool slowly.
A
Increase welding current
B
Use smaller diameter
electrode.
C
Allow wider gap.
D Use correct build-up sequence.
A
Use larger electrodes and pre-heat
the plate.
B
Increase welding current
C Adjust angle so the welding arc is
directed more into the base metal
D Reduce travel speed of electrode
E Clean surface before welding.
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