Which shielding method is used by GMAW (MIG) welding?

Which shielding method is used by GMAW (MIG) welding?

• A. Flux shielding
• B. External shielding gas
• C. Self-shielded flux-core
• D. Arc shielding by plasma breakdown

Answer: (B)

GMAW, or MIG welding, relies on shielding gas delivered through the welding torch to protect the arc and the molten weld from the atmosphere. This external shielding gas blankets the weld area, displacing air and preventing oxidation, porosity, and contamination from nitrogen and oxygen. The gas also helps stabilize the arc and can influence bead shape and penetration depending on the gas type and mixture used (such as argon, CO2, or gas blends). This approach is what distinguishes standard MIG welding from methods that rely on flux in the wire itself for shielding, or from concepts like shielding by plasma breakdown, which aren’t used to protect the weld in MIG welding.

GMAW, or MIG welding, relies on shielding gas delivered through the welding torch to protect the arc and the molten weld from the atmosphere. This external shielding gas blankets the weld area, displacing air and preventing oxidation, porosity, and contamination from nitrogen and oxygen. The gas also helps stabilize the arc and can influence bead shape and penetration depending on the gas type and mixture used (such as argon, CO2, or gas blends). This approach is what distinguishes standard MIG welding from methods that rely on flux in the wire itself for shielding, or from concepts like shielding by plasma breakdown, which aren’t used to protect the weld in MIG welding.