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  • DEUTSCH, seite 19
when welding on maximum settings.
6.2. GENERAL WELDING TIPS
From time to time, some faults may be observed in the weld owing to external influences rather due to welding machine's
faults. Here are some that you may come across :
·
Porosity
Small holes in the weld, caused by break-down in gas coverage of the weld or sometimes by foreign bodies inclusion.
Remedy is, usually, to grind out the weld.
Remember, check before the gas flux (about 8 liters/minutes), clean well the working place and finally incline the torch while
welding.
·
Spatter
Small balls of molten metal which come out of the arc. A little quantity is unavoidable, but it should
be kept down to a minimum by selecting correct settings and having a correct gas flow and by keeping the welding torch clean.
·
Narrow heap welding
Can be caused by moving the torch too fast or by an incorrect gas flow.
·
Very thick or wide welding
Can be caused by moving the torch too slowly.
·
Wire burns back
It can be caused by wire feed slipping, loose or damaged welding tip, poor wire, nozzle held too close to work or voltage too
high.
·
Little penetration
It can be caused by moving torch too fast, too low voltage setting or incorrect feed setting, reversed polarity, insufficient
blunting and distance between strips. Take care of operational parameters adjustment and improve the preparation of the
workpieces.
·
Workpiece's piercing
It may be caused by moving the welding torch too slow, too high welding power or by an invalid wire feeding.
·
Heavy spatter and porosity
It can be caused by nozzle too far from work, dirt on work or by low gas flow. You have to the two parameters, remeber that gas
has not to be lower than 7-8 liters/min. and that the current of welding is appropriated to the wire you are using. It is advisable
to have a pressure reducer of input and output. On the manometer you can read the range expressed in liter.
·
Welding arc instability
It may be caused by an insufficient welding voltage, irregular wire feed, insufficient protective

7. FAULT FINDING

FAULT
Wire isn't conveyed when
feed roll is turning
Wire feeding in jerk or
erratic way
No arc
Porous welding seams
REASON
1) Dirt in liner and/or contact tip
2) The friction brake in the hub
is tightened too hard
3) Faulty welding torch
1) Contact tip defect
2) Burns in contact tip
3) Dirt in feed roll groove
4) Feed roll's groove worn
1) Bad contact between
earth clamp and workpiece
2) Short-circuit between contact
tip and gas shroud
1) Failure of gas shield owing
to spatters in gas shroud
2) Wrong welding torch distance
and/or inclination
from workpiece
- 16 -
welding gas.
REMEDY
Blow with compressed air, replace
contact tip
Loosen
Check sheating of torch's wire
guide
Replace
Replace
Clean
Replace
Tighten earth clamp and
check connections
Clean, replace tip and/or shroud
as necessary
Clean gas shroud from spatters
The length of stick out wire from
tip to workpiece must be 5-10 mm.
Inclination not less than 60 degrees

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