MIG/MAG welding is a melting welding method. When performing this type of welding, the metal electrode is used both, as an agent to carry the electric arc and as a welding additive. The welding blowpipe is filled with "endless" welding wire through a drive pulley.
The end of the wire is surrounded by a gas nozzle, the protective gas passes through the nozzle to prevent chemical reactions with oxygen. The strength and toughness of the welding joint is thus preserved.
Two types of shielding gases determining the form of a welding joint and material transition are used:
- inert gas (MIG) – is a little reactive gas used for welding of all metals other than steel. It has a purely protective function.
- active gas (MAG) - consists of a mixture of noble gases which contain an amount of carbon dioxide and react well. In addition to its protective function, it is used to enter into chemical reactions in the weld pool.
The welding apparatus for MIG / MAG welding consists of a welding power source, a gas cylinder of shielding gas, a reducing valve with flow meter, a container for welding current, a feed device and a welding blowpipe.
The advantages of MIG / MAG
- good burning performance
- deeper weld
- easy handling
- possibility of mechanization and automation
- high efficiency
- improved environmental hygiene
- possibility to weld in all positions
Disadvantages:
- high incidence of defects (cold joint, weak joint)
- need for constant air supply