What polarity is used for GMAW welding?

What polarity is used for GMAW welding?

• A. DCEP (DCRP)
• B. DCEN
• C. AC
• D. DCGP

Answer: (A)

In GMAW, polarity determines where most of the arc heat goes and how the filler wire transfers into the weld pool. The standard setup is direct current with the electrode as the positive terminal (reverse polarity). This arrangement delivers more heat into the weld pool, which promotes deeper penetration and a stable arc when shielding gas is used, especially with spray or globular transfer modes that are common in MIG welding. That combination gives efficient deposition and a smooth, consistent bead on many steels and thicker sections. Using electrode negative reduces heat in the weld area and is more typical for short-circuit transfer on thin materials, where gentler heat input is desired. AC is used in aluminum welding to help break up oxide films, but for typical GMAW on steels, reverse polarity is the go-to.

In GMAW, polarity determines where most of the arc heat goes and how the filler wire transfers into the weld pool. The standard setup is direct current with the electrode as the positive terminal (reverse polarity). This arrangement delivers more heat into the weld pool, which promotes deeper penetration and a stable arc when shielding gas is used, especially with spray or globular transfer modes that are common in MIG welding. That combination gives efficient deposition and a smooth, consistent bead on many steels and thicker sections. Using electrode negative reduces heat in the weld area and is more typical for short-circuit transfer on thin materials, where gentler heat input is desired. AC is used in aluminum welding to help break up oxide films, but for typical GMAW on steels, reverse polarity is the go-to.