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No.
Problem
Root Cause
What to do
7
When torch
trigger is
pressed and
held, wire feeder
fails and there is
no indication of
open circuit
voltage.
Torch trigger damaged.
Replace the torch.
Broken wire feeding control.
Repair the wire
feeding control cable.
Damaged control circuit board.
Replace the control
circuit board.
3. Common Welding Imperfections and Analysis
No.
Imperfect
Root Cause
1
Porosity
1. Impure gas or insufficient gas supply.
2. Absorption of air during welding.
3. Failed preheater.
4. Poor gas shielding owing to strong wind.
5. Torch nozzle blocked by spatter.
6. Too great a distance between nozzle and
workpiece.
7. Polluted welding surface with oil and dust or
moisture caused from insufficient cleaning not
sufficiently removed.
8. Arc length too long and voltage too high.
9. Insufficient silicon and manganese content in
welding wire
.
