Weldskill 100 inverter, 05 welding problems – Tweco 100 Weldskill User Manual
Page 35

weldskill 100 iNVeRTeR
5-3
March 3, 2008
5.05 Welding Problems
Description
Possible Cause
Remedy
1 Gas pockets or voids in weld metal
(Porosity)
A Electrodes are damp
A Dry electrodes before use
B Welding current is too high
B Reduce welding current
C Surface impurities such as oil,
grease, paint, etc
C Clean joint before welding
2 Crack occurring in weld metal soon
after solidification commences
A Rigidity of joint
A Redesign to relieve weld
joint of severe stresses
or use crack resistance
electrodes
B Insufficient throat thickness
B Travel slightly slower to
alloy greater build-up in
throat
C Cooling rate is too high
C Preheat plate and cool
slowly
3 A gap is left by failure of the weld
metal to fill the root of the weld
A Welding current is too low
A Increase welding current
B Electrode too large for joint
B Use smaller diameter
electrode
C Insufficient gap
C Allow wider gap
D Incorrect sequence
D Use correct build-up
sequence
Insufficient Gap
Incorrect Sequence
Art # A-05866_AB
Figure 5-1: Example of Insufficient Gap or Incorrect Sequence
Description
Possible Cause
Remedy
4 Portions of the weld run do not fuse
to the surface of the metal or edge of
the joint
A Small electrodes used on
heavy cold plate
A Use larger electrodes and
preheat the plate
B Welding current is too low
B Increase welding current
C Wrong electrode angle
C Adjust angle so the welding
arc is directed more into
the base metal
D Travel speed of electrode is
too high
D Reduce travel speed of
electrode
E Scale or dirt on joint surface E Clean surface before
welding