A generic term denoting a treatment, consisting of heating to and holding at a suitable
temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, but
also to simultaneously produce desired changes in other properties or in microstructure. The
purpose of such changes may be, but is not confined to: improvement of machinability,
facilitation of cold work, improvement of mechanical or electrical properties, and/or increase in
stability of dimensions. When the term is used without qualification, full annealing is implied.
When applied only for the relief of stress, the process is properly called stress relieving or stressrelief
In ferrous alloys, annealing usually is done above the upper critical temperature, but the timetemperature
cycles vary widely in both maximum temperature attained and in cooling rate
employed, depending on composition, material condition, and results desired. When applicable,
the following commercial process names should be used: black annealing , blue annealing , box
annealing , bright annealing , cycle annealing , flame annealing , full annealing , graphitizing ,
intercritical annealing , isothermal annealing , malleablizing , order hardening , process annealing
, quench annealing , spheroidizing , subcritical annealing .
In nonferrous alloys, annealing cycles are designed to: (a) remove part or all of the effects of cold
working (recrystallization may or may not be involved); (b) cause substantially complete
coalescence of precipitates from solid solution in relatively coarse form; or (c) both, depending
on composition and material condition. Specific process names in commercial use are final
annealing , full annealing , intermediate annealing , partial annealing , recrystallization annealing
, stress relieving ,anneal to temper .