Gas Tungsten Arc Welding (TIG)

The Gas Tungsten Arc Welding process which was introduced in the late 1930's, was the forerunner of the actual gas shielded welding processes. In this process the necessary welding heat input is provided by an electric arc which is struck between a non consumable tungsten or thorium alloyed tungsten (2%) electrode and the work piece. In 1944 Russels Meredith received a patent for welding magnesium and magnesium alloys using a tungsten electrode to provide the arc and shielding the arc with a helium or argon atmosphere.

This process which is called "Gas Tungsten Arc Welding" or TIG Welding (Tungsten Inert Gas) is mainly used in welding corrosion resistant steels and other difficult to weld metals such as aluminium and magnesium. The only disadvantage is that the welding speed is rather slow and the welder must be well trained.

The most important advantages of the TIG welding process are:

• Independent control of the heat input and filler metal deposition.
• Superior quality welds and excellent root pass penetration.
• Inexpensive welding machines.
• Free of distortion weldings.
• Welding of all, including dissimilar metals.