WIA Iss A, Руководство оператора

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14
Operators Manual
Quality
•
Reliability
•
Performance
Unsatisfactory Welding Performance
and Results
Erratic arc characteristics caused by poor
wirefeed
Erratic wirefeed is the MOST LIKELY cause of
failure in all Gas Metal Arc Welding. It should
therefore be the first point checked when
problems occur.
1 Refer to the Wirefeeder Operators Manual
for wirefeed trouble shooting
2 Check if the consumable wire is slipping
in the drive rolls. Replace the feed roll if it
is the incorrect size or is worn
3 Check that gun cable liner is not too
short and is fitted correctly. Refer to the
wirefeeder Operators Manual for fitting
instructions.
Constant poor arc characteristics
Check that the:
1 Correct polarity has been selected for
work and weld cables (refer page 8)
2 Shielding gas is correct for the
consumable wire in use (refer page 10)
3 Welding circuit is making good electrical
connection. Ensure that the work clamp is
securely tightened onto the work piece so
that good electrical contact is achieved
4 All connections in the external welding
circuit are clean and tight. Problems may
show as hot spots
5 Work piece surface is not contaminated.
Water, oil, grease, galvanising, paint,
or oxide layers can severely disturb the
welding arc and result in a poor weld.
Porosity (honeycomb appearance) in
weld
1 Check the gun nozzle and gas diffuser
holes are free from spatter and firmly
attached to the welding gun to ensure
that no air is being drawn into the
shielded area
2 Check that the correct gas flow rate has
been set (refer page 10)
3 Check for leaks in the gas hose. Replace if
leaking
4 Check for leaks in gun/cable assembly, eg.
fractured gas hose, broken or missing ‘O’
rings. Replace as required
5 Check the work piece surface and MIG
wire for contamination. Water, oil, grease
or paint can result in porosity in the weld.