Millwright Level 1 Practice Exam

What effect does straight polarity have in the welding process?

1. Deeper penetration with slow welding speed

2. Shallow penetration and faster welding speed

3. No significant impact on the weld

4. Increased heat but low welding speed

The correct answer is: Shallow penetration and faster welding speed

Straight polarity, also known as DCEN (Direct Current Electrode Negative), has a significant effect on the characteristics of the welding process. When using straight polarity, the current flows from the workpiece to the electrode, resulting in a portion of the heat being concentrated on the workpiece. This causes a shallow penetration of the weld. Additionally, straight polarity allows for higher travel speeds due to the more concentrated arc heat and heat being directed towards the base metal. This can lead to a more efficient welding process when less penetration is desired, which is often advantageous when welding thinner materials or when a fast welding process is required. Understanding this principle is crucial for millwrights, as it allows them to select the appropriate welding technique based on the materials and the desired weld characteristics.