An oxyfuel gas flame with an excess of fuel gas.
A reducing flame may be used to prevent oxidation of an active metal, so that wetting is not hin- dered or unacceptable dross is not produced. The reducing flame may also preclude loss of a key oxidizable alloying element, such as carbon. Specific to plain and alloyed steels, a reducing flame imparts carbon into the surface of the weld metal. In such situations, a reducing flame is often referred to as a carburizing flame. See also CARBURIZING FLAME, NEUTRAL FLAME, OXIDIZING FLAME, and REDUCING ATMOSPHERE.