What is the consequence of using incorrect polarity in GTAW?

Using incorrect polarity in Gas Tungsten Arc Welding (GTAW) can lead to poor arc stability and excessive spatter. In GTAW, the correct application of polarity is crucial; direct current (DC) with electrode negative (DCEN) is typically used for materials like steel to provide a stable arc, while alternating current (AC) with alternating polarity is often preferred for aluminum to allow for better cleaning action.

If the welding process is set to the wrong polarity, it can disrupt the balance of heat and the characteristics of the arc. This will usually manifest as an unstable arc, causing fluctuations in the welding process. Moreover, excessive spatter may occur due to improper melting of the filler material or workpiece, which complicates the performance of the welding arc.

Thus, correct polarity is essential to achieving a smooth and controlled weld, fostering not just better stability in the arc but also minimizing spatter for a cleaner welding operation.