What type of current is primarily used in GTAW?

In Gas Tungsten Arc Welding (GTAW), both direct current (DC) and alternating current (AC) can be used, which makes the choice indicating that both currents are primarily utilized correct. Each type of current has its distinct applications depending on the material being welded and the desired outcomes.

DC is commonly used for welding ferrous and non-ferrous metals because it provides a stable arc with deep penetration, which is essential for achieving strong welds in materials like stainless steel and aluminum. In contrast, AC is often preferred when welding aluminum due to its ability to clean the oxide layer off aluminum during the welding process. This is achieved through the reverse polarity that AC offers, alternating between the cleaning action and the welding action.

The ability to effectively use both current types allows welders to select the most appropriate one for the task at hand, making versatility a significant advantage of GTAW. Understanding when to use AC or DC is crucial for achieving the best results in various welding scenarios.