Gas metal arc welding

Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) and metal active gas (MAG) is a <a href="/facts/Welding/6EJ62mYV">welding</a> process in which an <a href="/facts/Electric_arc/1hUPPAG0">electric arc</a> forms between a consumable MIG <a href="/facts/Wire/yyy05H1S">wire</a> <a href="/facts/Electrode/251PaKX8">electrode</a> and the workpiece metal(s), which heats the workpiece metal(s), causing them to <a href="/facts/Heat_fusion/DWSCNDKe">fuse</a> (melt and join). Along with the wire electrode, a <a href="/facts/Shielding_gas/1tQgYGgt">shielding gas</a> feeds through the welding gun, which shields the process from atmospheric contamination.
The process can be semi-automatic or automatic. A constant <a href="/facts/Volt/KF18MXP2">voltage</a>, <a href="/facts/Direct_current/r9MNUx84">direct current</a> power source is most commonly used with GMAW, but constant <a href="/facts/Current_(electricity)/Dc1xdnUX">current</a> systems, as well as <a href="/facts/Alternating_current/qxICS3xa">alternating current</a>, 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.
Originally developed in the 1940s for welding <a href="/facts/Aluminium/7wmR8jYE">aluminium</a> and other <a href="/facts/Non-ferrous_metal/lY7X8rAY">non-ferrous materials</a>, GMAW was soon applied to <a href="/facts/Steel/aN6qWo4H">steels</a> because it provided faster welding time compared to other welding processes. The cost of <a href="/facts/Inert_gas/3EkBEoYh">inert gas</a> limited its use in steels until several years later, when the use of semi-inert gases such as <a href="/facts/Carbon_dioxide/xGzpppEp">carbon dioxide</a> became common. Further developments during the 1950s and 1960s gave the process more versatility and as a result, it became a highly used industrial process. Today, GMAW is the most common industrial welding process, preferred for its versatility, speed and the relative ease of adapting the process to robotic automation. Unlike welding processes that do not employ a shielding gas, such as <a href="/facts/Shielded_metal_arc_welding/DHSg8UGJ">shielded metal arc welding</a>, it is rarely used outdoors or in other areas of moving air. A related process, <a href="/facts/Flux-cored_arc_welding/k4pK3cWm">flux cored arc welding</a>, often does not use a shielding gas, but instead employs an electrode wire that is hollow and filled with <a href="/facts/Flux_(metallurgy)/ruKFTPGD">flux</a>.

Gas metal arc welding open-in-new

Gas metal arc welding