Full Annealing

Full Annealing

• The temperatures for full annealing are typically 50°C (90°F) above the upper critical temperature (A3) for hypoeutectic steels and the lower critical temperature (A1) for hypereutectoid steels.

• It is referred to as full annealing because it achieves full austenitization of hypoeutectoid steels.

• The indicated temperatures for full annealing are a supercritical anneal for hypoeutectoid steels, but are in the range of an intercritical anneal for hypereutectoid steels.

• Full annealing produces a microstructure that is softer and more amenable to other processing such as forming or machining.

• In addition, stainless and high-alloy steels may be austenitized (fully annealed) and quenched to minimize the presence of grain boundary carbides or to improve the ferrite distribution.

• The temperatures for full annealing are in approximately the same range of austenitization temperatures for water quenching (Fig.) but are below austenitization temperatures for either normalizing or hardening by oil quenching.



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