If the workpiece is positive, what polarity is used in DC welding?

In direct current (DC) welding, when the workpiece is designated as positive, the appropriate polarity used is direct current electrode negative (DCEN). This means that the electrode, which is typically the consumable part in a welding operation, is connected to the negative terminal of the power source, while the workpiece itself is connected to the positive terminal.

Using DCEN provides several advantages during welding. It allows for deeper penetration into the metal, which is essential when working with thicker materials, and results in a more stable arc. When the electrode is negative, a larger proportion of the heat produced during the welding process is concentrated on the workpiece rather than the electrode itself. This helps in better melting and fusing of the base materials.

In contrast, other polarity options—like direct current electrode positive (DCSP)—would have the electrode as positive, resulting in shallower penetration and more heat being generated at the electrode rather than the workpiece. Alternating current (AC) is also not applicable here, as it oscillates between positive and negative, which does not provide the focused penetration characteristic of DCEN. Therefore, using DCEN is the correct and most effective choice when the workpiece is positive in DC welding.