| The Gas Tungsten Arc Welding (GTAW) method was developed in the 1940s for welding of aluminum and magnesium alloys.
Besides aluminum and magnesium, the GTAW method is used to weld stainless steels, as well as carbon and low-alloy steels. The primary application area for GTAW is welding of thin metals, < 6 mm.
In GTAW welding, an electric arc is used to heat and melt the material. The electric arc burns between the electrode and the work piece. A shielding gas that flows through the gas nozzle protects the weld pool and the electrode. The electrode is centrally positioned in the gas nozzle.
The key purpose of the shielding gas in GTAW welding is to protect the hot and molten parts of the work piece, the filler metal and the electrode from the deleterious influence of the surrounding air. In addition, the shielding gas affects the characteristics of the arc and the appearance of the weld.
Typical shielding gases consist of argon, helium or mixtures thereof. The addition of hydrogen or nitrogen can also be beneficial under certain conditions.
Typical applications for GTAW welding are welding of pipes, pressure vessels and heat exchangers. Since GTAW welding can be used to weld thin metals and small objects, the method is also used in the electronic industry.
The advantages of GTAW welding include very high weld quality, absence of slag and very little spatter. The method is extremely versatile, since most weldable materials can be GTAW welded and many welding positions and joint configurations can be used. |
