Gas Tungston Arc Welding, GTAW, TIG Review
Gas Tungston Arc Welding, GTAW, TIG - this is the form of electric arc welding that fills most of the needs in industry. It is more commonly known as Tungsten Inert Gas (TIG) welding and by the trade names of Heliarc or Heliweld. These trade names were derived from the fact that the inert gas originally used was helium.
(1) Rather than using a consumable electrode, the electrode in TIG welding is a tungsten rod. The 250+ amp arc between the electrode and the work melts the metal at 5,432 deg. F, and a filler rod is manually fed into the molten puddle. A stream of inert gas such as argon or helium flows out of the torch and envelopes the arc, thereby preventing the formation of oxides in the puddle.
(2) The versatility of TIG welding is increased by the power supply that is used. Direct current of either polarity or alternating current may be used.
TIG welder uses DC current, straight polarity for welding mild steel, stainless steel and titanium.
TIG uses AC current for welding aluminum and magnesium.