| TIG stands for Tungsten Inert Gas. Welding is done with an electrical arc, operating between the workpiece and a non-melting tungsten electrode. The arc is surrounded with an inert gas or gas mixture. Filler metal can be used, and is added separately if required. TIG welding is a very flexible process.
The purpose of the welding gas is to protect the electrode and the molten weld metal from the adverse effects of the surrounding atmosphere. The gas will influence the process characteristics and the appearance of the weld metal, as well as the economy of the welding operation.
Typical welding gases contain argon, helium and mixtures of these gases. Under certain conditions, hydrogen and nitrogen may be added in small amounts.
TIG welding can be done with DC or AC. DC is the preferred method, although AC can be beneficial in some cases such as welding of aluminum.
Typical applications for TIG welding include pipes, pressure vessels and heat exchangers. Since TIG welding can be used to weld thin metals and small objects, the method is also used in the electronics industry.
The advantages of TIG welding include very high weld quality, absence of surface slag and very little spatter. The method is extremely versatile, since most materials can be TIG-welded and it offers a wide choice of welding positions and joint configurations. |
