Annealing

A generic term denoting a treatment, consisting of heating to a soak temperature 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, production of a desired microstructure (for subsequent operations), improvement of mechanical or electrical properties, and/or increase instability of dimensions. When the term is used without qualification, full annealing is implied, for stress relieving, or stress-relief annealing.