CIGWELD TRANSTIG 300 AC/DC, Руководство по обслуживанию, Страница: 50 / 134

TRANSTIG 300 AC/DC SERVICE MANUAL
10-4 June 30, 2008
10.02 Stick Welding Problems
Description Possible Cause Remedy
1 Gas pockets or
voids in weld metal
(Porosity).
A
B
C Electrodes are damp.
Welding current is too high.
Surface impurities such as oil,
grease, paint, etc. A
B
C Dry electrodes before use.
Reduce welding current.
Clean joint before welding.
2 Crack occurring in
weld metal soon
after solidification
commences.
A
B
C
Rigidity of joint.
Insufficient throat thickness.
Cooling rate is too high. A
B
C
Redesign to relieve weld joint of
severe stresses or use crack
resistance electrodes.
Travel slightly slower to allow
greater build up in throat.
Preheat plate and cool slowly.
3 A gap is left by
failure of the weld
metal to fill the root
of the weld.
A
B
C
Welding current is too low.
Electrode too large for joint.
Insufficient gap. A
B
C
Increase welding current
Use smaller diameter
electrode.
Allow wider gap.
D Incorrect sequence. D Use correct build-up sequence.
Table 10-2: Stick Welding Problems
Incorrect sequence
Insufficient
gap
Art # A-04991
Figure 10-1: Example of Insufficient Gap or Incorrect Sequence