MIG or MAG welding (the only difference is the gas that is used as a shielding gas) is a welding process that was developed after the Second World War that has grown in practice year after year.
MIG/MAG welding is a constant voltage process where a shield gas is used to protect the welding from contaminants. The fact that it is a constant voltage process guarantees increased productivity, while the continuous gas prevents slag. MIG welding is easier, more practical, and faster than TIG, and is used when productivity and simplicity are important. The elevated current density (100-250 A/mm²) allows for an increased deposition rate.
The welding system is very cumbersome and complex and requires an electric circuit, a circuit for the shielding gas, a circuit to cool the water (most modern pistols are self-cooling, the shielding gas itself prevents overheating), the torch containing the wire, and the wire feed device. During welding, the wire electrode, the bath, the arc, and the area surrounding the materials are protected from atmospheric contamination by the inert gas supplied by the pistol. It is important to consider the means of transporting the materials.