Which numbers represent electrodes that operate in DCEN?

Electrodes that operate in direct current electrode negative (DCEN) involve the polarity of the electrical current during welding. In DCEN, the electrode is the negative terminal, and the workpiece is the positive terminal. This configuration provides several benefits, including deeper penetration and increased heat concentration at the weld joint.

The correct choice encompasses the electrode classifications specifically designated to operate under DCEN conditions, according to the welding codes and standards. Electrode numbers 7 through 11 are recognized for their suitable characteristics that align with DCEN usage, including their composition and behavior under this polarity, making them optimal for various welding applications where these conditions are required.

The other ranges of electrode numbers do not conform to DCEN operation, either because they belong to different welding processes or are designed for alternating current (AC) or direct current electrode positive (DCEP) applications, which have different characteristics and are suited for different welding situations. Understanding the properties of these electrode types is crucial for selecting the appropriate method for welding tasks that require specific penetration, heat, and metal fusion characteristics.