PATON
VDI-SERIES PRO
DC MMA/TIG/MIG/MAG
-21-
4.4. LINEAR INCREASE OF WELDING CURRENT
This function provides the economic consumption of an electrode, promotes the extension
of the service life of the welding torch, and facilitates the use of the welding torch. This
function prevents the spillage of molten metal in the welding pool. Additionally, during
the period
[t.uP]
of linear increase of the welding current, it is possible to accurately
locate the welding torch in the weld area, as the arc starting point not always is in the
weld area. It may be reasonably to heat the weld area. By default, the period of linear
increase of welding current is 1.0 s.
The procedure for changing the values of the operational parameters of the welding unit is
described in Section 6.1.
4.5. WELDING AT PULSE WELDING CURRENT
This function is designed to simplify the control of a welding process in various spatial
welding positions, excluding a flat welding position. This function is also used in welding
nonferrous metals. When this function is activated, the application of pulse welding
current improves the mixing of molten metals in the weld area and causes forced action
on the transfer of molten metal drops into the welding pool, therefore the stability of the
weld formation and the stability of the welding process are improved. The pulse welding
current in the manual arc welding process affects the weld parameters similar to the
movement of the operator hand in manual arc welding process, specifically at hard-to-
reach places. The proper adjustment of the welding process parameters in the welding at
pulse welding current has a direct effect on the weld quality, specifically reduces weld
metal porosity and decreases the graininess of the weld metal. As a result of the improved
weld quality, the weld strength increases.
To activate this function, it is necessary to set the following three operational parameters
of the welding process: current pulse amplitude
[Po.P],
current pulse frequency
[Fr.P]
,
and duty cycle
[dut]
. By default, the current pulse amplitude is 0 [OFF], that is, the
function is switched off, the current pulse frequency is 5 Hz, and the duty cycle is 50 %.
To activate the function, set the current pulse amplitude higher than 0. The current pulse
amplitude should be set in percentage of the welding current specified for the welding
process.
Example
Welding is to be performed with welding nonconsumable tungsten electrode 2.0 mm
in diameter.
The set welding current is 100 A.
The current pulse amplitude is 30 %.
The current pulse frequency is 5 Hz (default value).
The duty cycle is 50 % (default value).
The result is the following: the welding current pulse amplitude will be in the range of
70 … 130 A, the current pulse frequency will be 5 Hz, and the current pulse length will
be equal to the length of an interval between pulses. If the duty cycle is not equal to
50 %, the current pulses will be nonsymmetrical relative to the intervals between pulses,
but the average welding current value will be equal to the set welding current value of
