With what polarity is the GMAW process typically welded?

The Gas Metal Arc Welding (GMAW) process is typically conducted using Direct Current (DC) with the electrode being negative, which is known as DC Negative. This polarity is preferred because it provides a stable arc and efficient heat generation directly at the weld pool, allowing for better control over penetration and bead appearance.

When using DC Negative polarity, approximately 70% of the heat is generated at the workpiece, which helps ensure proper fusion and can facilitate smoother welding operations. This is particularly advantageous when welding materials such as low carbon steel, as it typically results in a more desirable weld profile and reduces the likelihood of defects.

This understanding of polarity is crucial for welders to ensure effective and quality welds, aligning with the processes outlined in the Structural Welding Code. The other options, such as AC or DC Positive, do not align with the standard practices of GMAW, which emphasizes the efficiency and stability of DC Negative polarity for various welding applications.