TIG welding (Tungsten Inert Gas arc Welding)

TIG welding (Tungsten Inert Gas arc Welding), also known as tungsten inert gas welding. TIG welding is also used for thicker sections root pass welding, the main welds surfacing.

The heat source is a DC TIG welding arc, the working voltage of 10 to 15 volts, but the current up to 300 A, the workpiece as the positive electrode, the tungsten electrode welding torch as the cathode. The inert gas is usually argon.

The process of TIG welding:

Inert gas fed through the torch, the arc weld pool on the sides and form a shield. To increase the heat input, generally within the argon with 5% hydrogen. However, in the ferritic stainless steel welding, argon within not hydrogenated. Gas consumption per minute, about 8 to 10 liters. In the welding process, in addition to inert gas is blown from the welding torch, the best protection is also blown into the weld seam from the back with a gas.

Classification
TIG manual welding divided by mode of operation, semi-automatic and automatic welding categories. GTAW, the torch movement and adding filler wire entirely by hand operation; semi-automatic TIG welding, torch movement by manual operation, but the filler wire by wire feeder automatic feeding; Automatic TIG arc welding, such as workpiece stationary arcing motion, then the welding torch mounted on a small car, the car or walking and filler wire can be used cold or hot filament yarn way to add. Hot wire means increasing deposition rate. Some occasions, such as sheet metal welding or weld backing, sometimes without adding filler wire. The three welding methods, GTAW most widely used, semi-automatic TIG welding is rarely used.