Which polarity would have higher electrode burn-off rates?

Which polarity would have higher electrode burn-off rates?

• A. Straight polarity
• B. Reverse polarity
• C. AC
• D. DC positive

Answer: (A)

Heat distribution determined by electrode polarity controls how quickly the electrode wears away. When the electrode is the positive electrode (straight polarity), more heat is delivered to the electrode itself, causing the electrode metal and its coating to melt and burn away faster. This makes the burn-off rate higher with straight polarity. With reverse polarity, the heat is focused more in the workpiece, so electrode consumption is reduced and penetration increases. Alternating current also distributes heat over both sides over time, leading to less constant heating of the electrode than straight polarity. So the highest electrode burn-off rate occurs with straight polarity.

Heat distribution determined by electrode polarity controls how quickly the electrode wears away. When the electrode is the positive electrode (straight polarity), more heat is delivered to the electrode itself, causing the electrode metal and its coating to melt and burn away faster. This makes the burn-off rate higher with straight polarity. With reverse polarity, the heat is focused more in the workpiece, so electrode consumption is reduced and penetration increases. Alternating current also distributes heat over both sides over time, leading to less constant heating of the electrode than straight polarity. So the highest electrode burn-off rate occurs with straight polarity.