PRO-POINT 8611311 Manuel D'utilisation page 21

V1.0
ANGLE TO WORK
The work angle is the forward or
back angle of the gun relative to
the workpiece.
The correct work angle provides
good bead shape, prevents
undercut, uneven penetration,
poor gas shield and poor quality
finished weld (Fig. 37).
STICK OUT
Stick out is the length of the unmelted wire protruding from the end of the contact tip.
A constant even stick out of 1/8 to 1/4 in. (Fig. 38) will produce a stable arc and an even current
flow providing good penetration and even fusion (Fig. 39). A stick out that is too short will cause
an unstable weld pool,
produce spatter and over heat
the contact tip (Fig. 40). A
stick out too long will cause
an unstable arc, lack of
penetration, lack of fusion and
increase spatter (Fig. 41).
TRAVEL SPEED
Travel speed is the rate that the gun is moved along the weld joint and is usually measured in mm
per minute. Travel speeds can vary depending on conditions and the welder's skill and is limited to
the welder's ability to control the weld pool. Push technique allows faster travel speeds than Drag
technique. Gas flow must also correspond with the travel speed, increasing with faster travel speed
and decreasing with slower speed. Travel speed needs to match the amperage and will decrease as
the material thickness and amperage increase.
TOO FAST TRAVEL SPEED
A too fast travel speed produces too little heat
per inch of travel resulting in less penetration and
reduced weld fusion, the weld bead solidifies very
quickly trapping gases inside the weld metal
causing porosity. Undercutting of the base metal
can also occur and an unfilled groove in the base
metal is created when the travel speed is too fast
to allow molten metal to flow into the weld crater
created by the arc heat (Fig. 42).
TOO SLOW TRAVEL SPEED
A too slow travel speed produces a large weld
with lack of penetration and fusion. The energy
from the arc dwells on top of the weld pool rather
than penetrating the base metal. This produces a
wider weld bead with more deposited weld metal
per mm than is required resulting in a weld
deposit of poor quality (Fig 43).
CORRECT TRAVEL SPEED
The correct travel speed keeps the arc at the
leading edge of the weld pool allowing the base
metal to melt sufficiently to create good
penetration, fusion and wetting out of the weld
pool, producing a weld deposit of good quality
(Fig. 44).
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180 MULTI-PROCESS MIG-ARC-TIG WELDER
Correct Angle
Fig. 38
Not Enough Angle
Fig. 39 Fig. 40
8611311
Too Much Angle
Fig. 37
Fig. 41
Fig. 42
Fig. 43
Fig. 44
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