Thermal Arc 185 AC, Руководство по обслуживанию

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8-4 May 22, 2006
ARCMASTER 185 ACDC 200 ACDC
8.04 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
4 Portions of the weld run
do not fuse to the
surface of the metal or
edge of the joint
A
B
Small electrodes used on heavy cold
plate
Welding current is too low A
B
Use larger electrodes and pre-heat
the plate
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
Lack of fusion caused by dirt,
electrode angle incorrect,
rate of travel too high
Lack of side fusion, scale
dirt, small electrode,
amperage too low
Lack of inter-run
fusion
Lack of root fusion
Art # A-04992
Figure 8-2 - Example of Lack of Fusion
Incorrect sequence
Insufficient
gap
Art # A-04991
Figure 8-1 - Example of insufficient gap or incorrect sequence