LOKERMANN GRAND ARC 320 CEL PFC MV, Руководство пользователя

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3.3.4
DC TIG
Welding
trouble
shooting
The following chart addresses some of the common problems of DC TIG welding. In all cases of
equipment malfunction, the manufacturer’s recommendations should be strictly adhered to and
followed.
NO. Trouble Possible Reason Suggested Remedy
1
T ungsten burning
away quickly
Incorrect Gas or No Gas
Use pure Argon. Check cylinder has
gas, connected, turned on and torch
valve is open
Inadequate gas flow
Check the gas is connected, check
hoses, gas valve and torch are not
restricted.
Back cap not fitted correctly
Make sure the torch back cap is
fitted so that the o-ring is inside the
torch body
Torch connected to DC +
Connect the torch to the DC- output
terminal
Incorrect tungsten being used Check and change the tungsten type
if necessary
Tungsten being oxidised after
weld is finished
Keep shielding gas flowing 10–15
seconds after arc stoppage. 1 second
for each 10amps of weld current.
2 Contaminated
tungsten
Touching tungsten into the
weld pool
Keep tungsten from contacting weld
puddle. Raise the torch so that the
tungsten is off of the work piece 2 -
5mm
Touching the filler wire to the
tungsten
Keep the filler wire from touching
the tungsten during welding, feed the
filler wire into the leading edge of
the weld pool in front of the tungsten
3
Porosity - poor
weld appearance
and colour
Wrong gas / poor gas flow
/gas leak
Use pure argon. Gas is connected,
check hoses, gas valve and torch are
not restricted. Set the gas flow
between 6-12 l/min. Check hoses
and fittings for holes, leaks et
Contaminated base metal
Remove moisture and materials like
paint, grease, oil, and dirt from base
metal
Contaminated filler wire
Remove all grease, oil, or moisture
from filler metal
Incorrect filler wire
Check the filler wire and change if
necessary
4
Yellowish residue /
smoke on the
alumina nozzle &
discoloured
tungsten
Incorrect Gas Use pure Argon gas
Inadequate gas flow
Set the gas flow between 10 - 15
l/min flow rate
Alumina gas nozzle too small Increase the size of the alumina gas
nozzle
5
Unstable Arc
during DC welding
Torch connected to DC +
Connect the torch to the DC- output
terminal
Contaminated base metal
Remove materials like paint, grease,
oil, and dirt, including mill scale
from base metal.
Tungsten is contaminated
Remove 10mm of contaminated
tungsten and re grind the tungsten
Arc length too long
Lower torch so that the tungsten is
off of the work piece 2 - 5mm
6
Arc wanders
during DC welding
Poor gas flow
Check and set the gas flow between
10 - 15 l/min flow rate
Incorrect arc length
Lower torch so that the tungsten is
off of the work piece 2 - 5mm
Tungsten incorrect or in poor
condition
Check that correct type of tungsten
is being used. Remove 10mm from
the weld end of the tungsten and re
sharpen the tungsten
Poorly prepared tungsten
Grind marks should run lengthwise
with tungsten, not circular. Use
proper grinding method and wheel.
Contaminated base metal or
filler wire
Remove contaminating materials
like paint, grease, oil, and dirt,
including mill scale from base metal.
Remove all grease, oil, or moisture
from filler metal
7
Arc difficult to
start or will not
start DC welding
Incorrect machine set up Check machine set up is correct
No gas, incorrect gas flow
Check the gas is connected and
cylinder valve open, check hoses,
gas valve and torch are not
restricted. Set the gas flow between
10 - 15 l/min flow rate
Incorrect tungsten size or
type
Check and change the size and or the
tungsten if required
Loose connection Check all connectors and tighten
Earth clamp not connected to
work
Connect the earth clamp directly to
the work piece wherever possible