When using this type of current, greater penetration is achieved:

The correct choice is DCEP, which stands for Direct Current Electrode Positive. When using DCEP in welding, the flow of electrons moves from the electrode to the workpiece, which leads to greater heat concentration at the tip of the electrode. This concentrated heat results in deeper penetration into the base material, allowing for better fusion and stronger welds.

DCEP is particularly effective for processes such as Shielded Metal Arc Welding (SMAW) and Gas Metal Arc Welding (GMAW), as it aids in providing a cleaner weld with improved metal transfer and a stable arc. The deeper penetration qualities of DCEP make it advantageous for thicker materials that require more robust joinery.

In contrast, other current types, such as AC and DCEN, do not provide the same level of penetration because their heat distribution characteristics differ. AC current, while versatile and allowing for alternating flow of electricity that can help in minimizing the effects of arc blow, may not achieve the necessary heat concentration for deeper penetration in certain welding tasks. Similarly, with DCEN, the heat is concentrated on the workpiece rather than the electrode, resulting in shallower penetration and a narrower weld bead.