4 Importances Of AC vs. DC Welding: Know the Difference. WebDC welding is based on a DC straight polarity current, while AC welding alternates quickly between DC negative and DC positive. The applications of each vary with the material. Here is a handy table to help decipher the differences. Although DC welding is preferred for.

Web  More commonly used than AC welding, DC welding is considered to be superior in many regards. DC stands for direct current, meaning that the current is only flowing in one direction, and it flows.