What is the recommended polarity for welding stainless steel with GTAW?

Welding stainless steel with Gas Tungsten Arc Welding (GTAW) typically requires the use of direct current electrode negative (DCEN) polarity. This is because DCEN provides a stable arc and delivers more heat to the workpiece compared to the electrode, which is beneficial when welding materials like stainless steel that require a high degree of control over the heat input. The increased heat allows for better penetration and melting of the base material, resulting in a stronger weld.

Using DCEN also helps to minimize oxidation of the weld pool, which is crucial in stainless steel welding, as the presence of oxides can adversely affect the corrosion resistance of the material. The concentration of heat at the workpiece allows for a smoother flow of the molten metal, making it easier to achieve a high-quality weld with good aesthetics and mechanical properties.

While other polarities may have their applications in different welding scenarios, DCEN is specifically recommended for effective stainless steel welding in GTAW.