What type of currents is GMAW performed with?

GMAW, or Gas Metal Arc Welding, primarily utilizes direct current (DC) for the welding process, specifically focusing on two configurations: Direct Current Electrode Positive (DCEP) and Direct Current Electrode Negative (DCEN).

When using DCEP, the electrode is positive, and this configuration allows for better penetration into the base material while heating the weld pool, which is particularly beneficial for achieving a strong weld. DCRP, which stands for Direct Current Reverse Polarity, is often used to facilitate spray transfer modes that provide a smoother and more stable arc, making it suitable for welding thin materials and achieving high-quality welds.

The versatility in using both DCEP and DCEN allows welders to control arc characteristics and heat distribution effectively, which is crucial for different types of welding applications. This is why the answer highlights the significance of both DCEP and DCRP in the context of GMAW.

While GMAW can technically be performed using alternating current (AC), this is less common, especially for the types of metals and applications where GMAW excels. Thus, the combination of DC positive and negative provides the necessary control and performance characteristics essential to GMAW.