Clamped in the welding torch is a tungsten electrode in which the welding current is introduced.
Between the tungsten electrode and the workpiece an arc is formed which fuses the base material and melts the added filler metal.
Inert shielding gas streams out of the welding torch and screens off the glowing tungsten electrode as well as the welding pool from air.
The welding torch contains the tightly clamped tungsten electrode and the gas nozzle as well as, dependent on the current load, the channels for the water-cooling.
Usual shielding gas flow rate amount for argon, depending on the diameter of the gas nozzle and the welding condition is, 5 to 10 l/min. In the case of partly mechanized welding the filler will be added mechanically, not through the hose package, but separately.
The filler metal feed is regularly switched on separately whereas the turning on and off of the welding process is controlled by the torch.
The power supply consists of a steeply falling (constant current-) characteristics which has the effect that the amperage remains almost constant when the arc length changes.