Tweco 170 HF Weldskill - Manual (Page 39)

WELDSKILL 170 HF INVERTER
5-3 April 23, 2008
Art # A-05867_AB
Lack of inter-run fusion
Lack of side fusion,
scale dirt, small electrode,
amperage too low
Lack of root fusion
Lack of fusion caused by dirt,
electrode angle incorrect,
rate of travel too high
Figure 5-2: Example of Lack of Fusion
5 A groove has been formed in the
base metal adjacent to the toe of a
weld and has not been filled by the
weld metal (undercut).
A Welding current is too high. A Reduce welding current
B Welding arc is too long. B Reduce the length of the
welding arc
C Angle of the electrode is
incorrect.
C Electrode should not be
inclined less than 45° to
the vertical face
D Joint preparation does not
allow correct electrode
angle.
D Allow more room in joint
for manipulation of the
electrode.
E Electrode too large for joint. E Use smaller gauge
electrode.
F Insufficient deposit time at
edge of weave.
F Pause for a moment at
edge of weave to allow
weld metal build-up.
Possible Cause Description Remedy
Art # A-07714
Figure 5-3: Examples of undercut