Which current type is primarily used in Gas Tungsten Arc Welding?

In Gas Tungsten Arc Welding (GTAW), both alternating current (AC) and direct current (DC) are used depending on the specific requirements of the welding process and the materials being welded.

Direct current is frequently utilized for welding materials like steel and stainless steel, where it provides a stable arc and deeper penetration. It allows for better control of the heat input and is generally preferred for thicker materials.

On the other hand, alternating current is predominantly used for welding aluminum and magnesium. AC is essential in these materials because it allows for the cleaning action of the tungsten electrode due to the alternating polarities. This helps remove the oxidation layer from the surface of aluminum, which is critical for achieving a good weld.

By understanding that both types of current are essential for different applications in GTAW, one can effectively select the appropriate current type for a given welding scenario. This versatility is a significant advantage of the GTAW process, making it applicable in various industries and for different materials.