In regards to polarity, which polarity is used for deep penetration?

In regards to polarity, which polarity is used for deep penetration?

• A. DCEP
• B. DCEN
• C. AC
• D. Pulsed DC

Answer: (A)

Polarity controls how the arc heat is distributed between the electrode and the base metal, which directly affects how deeply the weld fuses into the joint. When the electrode is positive (electrode positive, base metal negative), more heat goes into the workpiece, producing deeper penetration. This is why deep penetration is achieved with reverse polarity. Using electrode negative concentrates more heat in the electrode, leading to shallower penetration, while alternating current changes polarity continuously and while convenient for many applications, it doesn’t inherently maximize penetration like reverse polarity does. Pulsed DC can help control heat input, but for the deepest weld penetration, the reverse-polarity setup is the best choice.

Polarity controls how the arc heat is distributed between the electrode and the base metal, which directly affects how deeply the weld fuses into the joint. When the electrode is positive (electrode positive, base metal negative), more heat goes into the workpiece, producing deeper penetration. This is why deep penetration is achieved with reverse polarity.

Using electrode negative concentrates more heat in the electrode, leading to shallower penetration, while alternating current changes polarity continuously and while convenient for many applications, it doesn’t inherently maximize penetration like reverse polarity does. Pulsed DC can help control heat input, but for the deepest weld penetration, the reverse-polarity setup is the best choice.