TOPGUN 3200 AC/DC TIG USER MANUAL
22
ALTERNATING CURRENT WELDING
–
TIG AC
TIG AC (AC) welding is used to connect magnesium or aluminum components and their alloys.
During AC welding, polarity changes between the poles positive and negative. A positive halfwave
allows the oxide surface layer to penetrate, while a half-wave negative, which is accompanied by a
decrease in the temperature of the electrode and heat flow to the workpiece, promotes deeper
arch penetration. By adjusting the AC wave balance, you can fine-tune the proportions between
spreading and penetrating electric arc.
For TIG AC welding, the most common electrode is pure tungsten (green) or tungsten with the
addition of lanthanum (gold color - recommended for low welding currents); preparation of the
electrode consists in appropriate blunting of the tip, which under the influence of high
temperature and electric arc takes a gradually rounded shape.
Both argon and helium can play the role of shielding gas in this welding method. generally
however, argon is used because it is cheaper and produces a more stable arc, which translates
into for greater maneuverability. However, it works better with some types of welds helium or a
mixture of helium and argon, which in addition to higher welding speeds also allows deeper
penetration.
Welding current selection
Select a
mode AC
Selection of the handle button operating
mode
2T
/
4T
