Argon oxygen decarburization (AOD) is a process primarily used in stainless steel making and other high grade alloys with oxidizable elements such as chromium and aluminum. After initial melting the metal is then transferred to an AOD vessel where it will be subjected to three steps of refining; decarburization, reduction, and desulfurization. The AOD process was invented in 1954 by the Lindé Division of The Union Carbide Corporation (which became known as Praxair in 1992).