When welding stainless steel (SS) using GTAW, which polarity is used?

When welding stainless steel using Gas Tungsten Arc Welding (GTAW), the correct polarity is Direct Current Straight Polarity (DCSP), also known as Direct Current Electrode Negative (DCEN). This polarity is particularly suitable for welding stainless steel because it focuses the heat generated in the weld area, providing a deeper penetration into the base metal. The heat is concentrated at the workpiece rather than the electrode, which helps avoid overheating the tungsten electrode and maintains the desired qualities of the stainless steel, such as its corrosion resistance.

In GTAW, using DCSP allows for better control over the weld pool, which is essential when working with stainless steel due to its tendency to distort if not managed properly. This makes it the preferred choice among welders for achieving high-quality welds in stainless steel applications. The other options represent different polarities or methods (like AC), which are not ideal for the specific requirements of stainless steel welding in GTAW processes.