Tungsten Inert Gas Welding (TIG Welding), also known as Gas Tungsten Arc Welding (GTAW), is an arc welding method that uses a non-consumable tungsten electrode to weld two or more workpieces. It is very much similar to Metal Inert Gas (MIG) Welding.
Components used in Tungsten Inert Gas Welding (TIG Welding):
The following components are necessary to perform Tungsten Inert Gas Welding:
- Power Supply (A.C or D.C)
- Non-consumable Tungsten Electrode
- Inert Gas Supply
- Filler Rod (used depending on the nature of workpiece)
- Welding Head
The workpiece to be welded is placed on the worktable. The non-consumable tungsten electrode and the workpiece are connected to the power supply (A.C or D.C).
As the electrode is brought near the workpiece (leaving a small air gap), an arc is produced. This arc is used for melting and welding the workpiece.
Tungsten has high melting point (3422 °C). Hence, tungsten electrode does not melt during the welding process.
In tungsten inert gas welding, filler rod may or may not be used. The usage of filler rod depends on the nature of the workpiece to be welded. If filler rod is used, it is continuously melted by the arc and fed into the weld pool.
Inert gas supply is constantly provided around the electrode during the welding process. The inert gas forms a gas shielding around the weld. It protects the weld from the external atmosphere. (See diagram above for better understanding).
Advantages of Tungsten Inert Gas Welding (TIG Welding):
- Tungsten Inert Gas Welding produces high quality welds.
- The weld is automatically protected by the inert gas during the welding process.
- No slag is produced.
- TIG Welding can be done in any position.
Disadvantages of Tungsten Inert Gas Welding:
- Tungsten inert gas welding is a slow process.
- Highly skilled labour is needed.
- Welder is exposed to huge intensities of light.
- TIG welding is more expensive when compared to MIG welding.
Applications of Tungsten Inert Gas Welding:
TIG Welding is used for welding a variety of metals. Some of them are:
- Stainless steel
- Alloy steel
- nickel alloys