Which polarity is required for stud welding in the qualification tests?

Which polarity is required for stud welding in the qualification tests?

• A. AC
• B. DCEN
• C. DCEP (straight polarity)
• D. DCAG

Answer: (C)

Heat distribution in an arc weld is controlled by polarity. In stud welding, the stud itself is the electrode, and you want the arc heat to be concentrated at the stud tip so the stud melts and fuses into the base metal in a very short, controlled burst. Straight polarity (positive on the stud, negative on the work) achieves that concentration of heat at the electrode, giving a stable arc and a strong, repeatable weld during qualification tests. If you use AC, the arc and heat shift direction, making the weld less consistent; if you use electrode-negative DC, more heat goes into the base metal and the stud may not melt properly, risking a weak or inconsistent joint. The DCAG option isn’t a standard polarity used for stud welding. So the required polarity is straight polarity, DCEP.

Heat distribution in an arc weld is controlled by polarity. In stud welding, the stud itself is the electrode, and you want the arc heat to be concentrated at the stud tip so the stud melts and fuses into the base metal in a very short, controlled burst. Straight polarity (positive on the stud, negative on the work) achieves that concentration of heat at the electrode, giving a stable arc and a strong, repeatable weld during qualification tests. If you use AC, the arc and heat shift direction, making the weld less consistent; if you use electrode-negative DC, more heat goes into the base metal and the stud may not melt properly, risking a weak or inconsistent joint. The DCAG option isn’t a standard polarity used for stud welding. So the required polarity is straight polarity, DCEP.