Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) welding or metal active gas (MAG) welding, is a semi-automatic or automatic arc
welding process in which a continuous and consumable
wire electrode and a
shielding gas are fed through a welding gun. A constant
voltage,
direct current power source is most commonly used with GMAW, but constant
current systems, as well as
alternating current, can be used. There are four primary methods of metal transfer in GMAW, called globular, short-circuiting, spray, and pulsed-spray, each of which has distinct properties and corresponding advantages and limitations.
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