An electric arc between a non-consumable tungsten electrode and the workpiece provides the heat needed for the welding operation. The tungsten electrode is not melted and any filler metal needed to build up the weld profile is added separately. The molten metal in the weld pool, the tip of the filler wire and the hot electrode are protected from atmospheric contamination by a shield of inert gas.
Usually the gas is argon, but helium by itself, or mixed with argon, may be used for special applications. Argon-hydrogen mixtures can be used for austenitic stainless steel.
I always use pure argon for TIG welding as it is versatile, what would you recommend to still give me versatility?
Alumaxx® Plus gives superior results with aluminium, its alloys and carbon steel; and Inomaxx® TIG is our best-in-class gas for austenitic stainless steel.