Which statement is true about current type for overhead welding on mild steel?

• A. Alternating current is used
• B. Direct current is used
• C. Both AC and DC are equally common
• D. Micro-surge current is used

Answer: (B)

Overhead welding on mild steel relies on a stable arc and predictable heat input so the molten pool can be kept under control despite gravity pulling the weld downward. Using direct current provides a more stable, controllable arc for MIG welding in the overhead position, which helps keep the puddle from wandering, sagging, or dripping. Alternating current reverses polarity each half cycle, which can make arc characteristics less predictable in the overhead orientation and complicate pool control. The term micro-surge current isn’t a standard setting for this process. So direct current is the true approach for overhead welding on mild steel.