What type of welding current is typically used in GTAW?

In Gas Tungsten Arc Welding (GTAW), the most commonly used type of welding current is direct current (DC). This is primarily because DC provides a steady and stable arc, which is essential for producing high-quality welds, especially when working with materials like stainless steel and aluminum. The direct current allows for better control of the heat input and provides a consistent arc characteristic, which is crucial for achieving good penetration and fusion of the base metal with the filler rod.

While alternating current (AC) can be used in GTAW, especially for aluminum and magnesium, it is not the standard choice for general applications. AC helps in cleaning the oxide layer from the aluminum surface, but it introduces some complexities in arc stability compared to DC. Variable current is not typical in GTAW applications as it would make it difficult to maintain a stable welding arc needed for precise work. High-frequency current is not a type of welding current itself but rather a feature of AC welders that helps to stabilize the arc at the start, making direct current the primary current type used for GTAW operations.