What type of current is primarily used in GMAW?

Gas Metal Arc Welding (GMAW) primarily utilizes direct current (DC) for effective operation. The use of DC in GMAW allows for a more stable arc and better control over the welding process, which is essential for achieving quality welds. DC provides a consistent polarity that contributes to smoother droplet transfer from the electrode to the workpiece, minimizing spatter and improving the overall arc stability.

In contrast, while alternating current (AC) can be used in certain applications, it is not as commonly employed in GMAW due to its fluctuating nature, which can lead to difficulties in maintaining an even arc. High-frequency current is generally associated with processes like TIG welding, where it is used to initiate and stabilize the arc but is not a primary current type for GMAW. Variable current suggests the use of adjustable current settings that may be fatigued across applications, but it does not clarify the consistent type of current standard to GMAW, which remains predominantly DC.