MIG/MAG

MAG – Metal Active Gas (ISO 4063: process 135)

• Shielding gas: Active mixtures (e.g. Ar + 15–25% CO₂ [M21], Ar + 2–5% O₂ [M12] – per ISO 14175)
• Used for: Carbon steels, low-alloy steels, structural steels
• Common wires:
  • Unalloyed steels: G3Si1 / ER70S-6
  • Low-alloy steels: G4Si1, ER80S-D2, etc.
• Typical ISO classification: ISO 14341 for MIG/MAG is currently the most frequently used welding process and allows for particularly high welding speeds. It can be used in a manual, mechanized or robot-supported manner.
  In MIG/MAG welding, a filler metal or welding wire ignites the arc if it touches the component. The consumable wire is used as allowance.

In order to protect the arc from the reactive oxygen in the surroundings, a “shielding gas” also flows through the gas nozzle. This suppresses the oxygen during welding and therefore prevents oxidation on the arc and on the weld pool.

MIG welding requires inert gas such as argon or helium. The primary purpose of the welding gas is to protect the weld pool and surrounding area from atmospheric contaminants. Gas mixtures are preferred by most professional welders in order to achieve required fusion, arc stability and a smooth, clean weld.

MIG brazing is a variant of MIG welding used to join ferrous materials. During MIG brazing, filler metal is melted but parent metal is not. Only inert or reducing gases used as the shielding gas such as argon, argon/helium mixtures and argon hydrogen mixtures.