PRO-POINT PN105I Manuel D'utilisateur page 15

V1.0 GASLESS MIG WELDER PN105I 8958696
TRAVEL ANGLE
Not Enough Angle Angle more than 20°
Angle 5° to 15°
Travel angle is the right to left
angle relative to the direction
of welding. A travel angle of 5°
to 15° is ideal and produces a
good level of control over the
weld pool. A travel angle
greater that 20° will give an
unstable arc condition with
Fig. 22
poor weld metal transfer, less
penetration, high levels of spatter, poor gas shield and poor-quality finished weld (Fig. 22)
ANGLE TO WORK
The work angle is the forward or
back angle of the gun relative to
the workpiece.
Correct Angle Not Enough Angle Too Much Angle
The correct work angle provides
good bead shape, prevents
undercut, uneven penetration,
poor gas shield and poor-quality
finished weld (Fig. 23).
Fig. 23
STICK OUT
Stick out is the length of the unbelted wire protruding from the end of the contact tip.
A constant even stick out of 1/8 to 1/4 in. (Fig. 24) will produce a stable arc and an even current
flow providing good penetration and even fusion (Fig. 25). A stick out that is too short will cause an
unstable weld pool, produce
spatter and overheat the
contact tip (Fig. 26). A stick
out too long will cause an
unstable arc, lack of
penetration, lack of fusion and
increase spatter (Fig. 27).
Fig. 24 Fig. 25 Fig. 26 Fig. 27
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. 28).
Fig. 28
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. 29). Fig. 29
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