Tig Welding Process - Fimer TT 162HF Bedienungsanleitung

The microprocessor manages the up and
down slopes of the current and gas flow
in order to optimise the welding process.
6.2.4 Selection of the Normal or
Pulsed welding process (TT168 -
TT205)
To select either the normal or pulsed
welding process, repeatedly press button
5 shown in figure 1 until LED 16 (normal
welding) or LED 15 (pulsed welding) light
up.
Normal welding process:
Once the welding current reaches the I2
values set with potentiometer 4 shown in
figure 1, the microprocessor regulating
circuit keeps the current at a constant
value for the entire duration of the weld-
ing.
Pulsed welding process:
In this case, the welding current does not
constantly remain at the I2 value set via
potentiometer 4 shown in figure 1, but
continues to switch-over between the I2
value and the much lower value of Is
(called the "background" current). The
switchover between the two values
occurs at a frequency that can be set via
potentiometer 2b (TT168 HF and TT205
HF). For machines TT168 DGT and
TT205 DGT, refer to paragraph 6.2.6.
At this point, the welding process can be
started.

6.2.5 TIG welding process

The following steps describe the proce-
dure to follow for welding in TIG Lift-Arc
mode:
1. Set the welding current via poten-
tiometer 4 shown in figure 1
2. Connect the ground terminal to the
workpiece.
3. Keeping the torch button pressed, reg-
ulate the gas flow via the tap (approxi-
mately, 6
litres/minute).
4. Lean the ceramic terminal of the torch
against the workpiece and turn until the
position shown in figure 7a is reached,
so that the tungsten electrode comes
into contact with the workpiece.
5. Press the torch button.
6. Slowly lift the tungsten electrode tip
from the workpiece using the ceramic
terminal of the TIG torch as a lever (fig-
ure 7b)
7. Once the arc has been struck, the current
gradually rises until reaching the set value.
8. Proceed with the welding process,
keeping the same distance from the weld
pool created.
9. To end the welding process, release
the torch button (or press it again in 4T
mode) and move the torch away from the
workpiece.
TIG welding with HF arc striking is very
similar to Lift-Arc striking and only differs
from point 4 onwards because the elec-
trode does not need to come into contact
with the workpiece but only within a dis-
tance of 3-4 mm, while the torch button is
kept pressed: in this way the arc is struck
without any contact between the elec-
trode and the piece to be welded.
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