What type of current is primarily used in GTAW?

In Gas Tungsten Arc Welding (GTAW), the use of current can vary depending on the materials being welded. Direct current (DC) is often employed for joining materials such as steel and stainless steel, providing a stable arc and superior control, which results in high-quality welds. On the other hand, alternating current (AC) is typically used for aluminum and magnesium, as it helps to remove the oxide layer that forms on these metals, allowing for a cleaner weld.

The versatile nature of GTAW allows the welder to select either AC or DC based on the specific requirements of the job. This adaptability is essential because different materials present unique challenges and properties that can affect how effectively they can be welded. Thus, the correct answer highlights the flexibility in current choice, ensuring welders can achieve optimal results for a variety of metal types.