Welding Quality; Welding With Infusible Electrode (Tig) - Helvi COMPACT 306C Manual De Uso

Electrode diameter Welding current
1.5mm
2.0m
2.5m
3.25mm
4.0mm
5.0mm
6.0mm
The following instructions can be useful for
good welding results:
• Delicately use the electrode (to avoid de-
terioration of the coating) to touch the piece
which is to be welded, to trigger the electric
arc.
• After triggering the arc, keep the electrode
in position at an angle of about 45° and move
it from left to right to control the arc and the
welding range.
• The length of the arc is a function of the
electrode/piece distance.
• Variations on the welding angle may incre-
ase the size of the welding area, improving
the covering capacity of the slag.
• When the welding is completed, allow the
residue to cool down before removing it with
a toe-ended brush.
Warning:
• Protect your eyes;
• Avoid injuries to you and other personnel
when removing the residue with the toe-
ended brush.
Warning!
A bad start can be caused by dirt on the
material to be welded, by the incorrect
connection between the ground lead and
the piece to be welded, or by the impro-
per fixing of the electrode holder.

WELDING QUALITY

The quality of the welding depends mainly on
the skill of the welder, the type of welding (pi-
ping, plates etc) and the quality of the electro-
de. Prior to welding, select the most suitable
model and diameter of electrode, being par-
ticularly careful regarding its thickness, the
composition of the metal to be welded and
the welding position (flat, front, descending/
ascending vertical etc).
30A - 50A
50A - 65A
70A - 100A
100A - 140A
140A - 180A
180A - 240A
240A - 270A
Tab.4
WELDING CURRENT
If current intensity is too high, the electrode
will burn too fast and the welding will be irre-
gular and difficult to control. If the current is too
low, you will lose power and the welding will
be narrow, irregular, with easy attachments
between the electrode and the piece.
ARC LENGTH
If the arc is too long, it will result in dripping
and in a small fusion of the piece being wor-
ked. If the arc is too short, the heat will not be
sufficient and the electrode will attach to the
piece being worked.
WELDING SPEED
Using a suitable welding speed, according
to the parameters employed, will allow for a
welding seam of the right size and with the
proper penetration.
WELDING WITH INFUSIBLE
ELECTRODE (TIG)
TIG welding with direct current is specifical
ly used to weld steel and stainless steel. For
these types of welding, it is advisable to use
non pure tungsten electrodes (not green).
The tip of the infusible electrode is tapered so
that the arc is stable and the energy is con-
centrated on the contact point/area which is
to be welded. The length of the tapering will
depend on the diameter of the electrode: with
low current, tapered tip with tapering length
l = 3 x d; with high current, rounded tip with
tapering length l = 1 x d.
Triggering the electric arc in Lift-Arc requi-
res contact between electrode and the piece
when the torch trigger is pressed.
The operational phases of the Lift Arc system
are:
• Lightly press the electrode on to the piece
which is to be welded (1).
• Press the torch button. The gas will flow
and the current will pass through the electro-
de.
• Move the electrode away from the piece,
rotating it so that the nozzle of the torch re-
Fig. 15
EN-13