Which materials use DCEN welding current?

• A. All materials
• B. Only metals with high melting points
• C. All materials except Aluminum and magnesium
• D. Aluminum and magnesium

Answer: (C)

DCEN stands for Direct Current Electrode Negative, and this polarity is commonly used for ferrous metals because it tends to produce a stable arc and effective heat distribution for those metals, giving good penetration and efficient electrode use. Aluminum and magnesium, however, have oxide skins that are difficult to weld through with DCEN, so welding of these light metals typically uses the opposite polarity (or AC) to help break up the oxide and maintain arc stability. That’s why DCEN is used for all materials except aluminum and magnesium.