Which polarity is commonly used for welding stainless steel?

In the context of welding stainless steel, the polarity commonly used is Direct Current Electrode Negative (DCEN). This polarity is preferred because it allows for better penetration of the weld into the base material, which is critical when working with stainless steel.

When DCEN is used, the majority of the heat is concentrated at the workpiece, which leads to a more controlled and stable arc. This is especially important for stainless steel, as it can be sensitive to heat input. Using DCEN minimizes the risk of warping or distorting the metal, which can often occur with improper heat management.

Other polarities, such as Alternating Current (AC) or Direct Current Electrode Positive (DCEP), may not provide the same level of control or penetration characteristics that are advantageous for welding stainless steel. AC is typically used for welding non-ferrous metals and DCEP can lead to excessive heat buildup in the electrode, potentially leading to damage or poor weld quality in stainless steel applications. Ground is not a polarity type but rather a connection point and doesn't apply to the welding process itself.

Therefore, choosing DCEN for welding stainless steel aligns with the need for optimal weld characteristics and heat control, making it the correct choice.