Holzmann PISA200AC/DC User Manual - page 31
OPERATION
HOLZMANN Maschinen Austria www.holzmann-maschinen.at
Seite 31
WIG/TIG Puls Inverter Schweißanlage / WIG/TIG Pulse inverter welding unit PISA200AC/DC
12.1.7 Advantages and application scope of pulse argon gas tungsten arc
welding
Precisely control the size of the bath inputting heat to workpiece to increase pene-
tration resistance of molten seam and preservation of bath. It is easy to obtain even
fusing deepness. This process is specially applicable to omni-bearing welding of sheet
and formation to be done with both sides through one side welding.
Heating and cooling of each welding point is very fast,.Therefore,the process is applicable
for the workpiece with great difference of heat conductivity and thickness.
Pulse arc can obtain greater fusing deepness with lower heat input.Therefore under
the same condition, the zone influenced from welding heat and deformation from
welding can be reduced. This is very important for sheet and ultra-thin sheet welding.
Fast cooling of the bath metal and shot duration time of high temperature during
welding can reduce cracks caused to the thermo-sensitive materials during welding.
12.1.8 Selection of welding parameters
Except for pulse current and the width time (width ratio) as well as pulse frequency
,welding parameters of pulse argon gas tungsten arc welding are as same as general
tungsten DC argon are welding. Pulse current increasing means electric arc can obtain
greater penetration ability.But too much current can cause local melting of tungsten
electrode.Generally,welding current required for DC tungsten argon are welding or greater
current is used. Arc holding current and base current influences cooling and crystallizing
of the metal in the bath. The range is determined by performance of the welding ma-
terials. When sheet is welding,smaller arc holding current (base current) is usually used
in order to reduce welding through and deformation.When pulse width ratio (holding time
of pulse current and base current) is selected, both the heat input and features of pulse
welding should be considered. Usually, it can be selected between 10%- 90 %. Selection
of pulse frequency (periodical change time of pulse current) mainly depends on thick-
ness of sheet and welding speed and operation custom of the operator should be also
considered.
12.1.9 AC ARGON ARC WELDING
put switch "12" (AC/DC) onto the position "AC".
The method of the connection same as 1.1
Reguting "13" to select right "sp"
SP= *100%
tp:the time of I2 at positive tn: the time of In at Negative
Regulating "15" to select right AC square wave frequency.
The Method of the welding same as 1.1