There are many types of heat treating processes available to steel. The most common are annealing, quenching, and tempering. Annealing is the process of heating the steel to a sufficiently high temperature to soften it. This process goes through three phases: recovery, recrystallization, and grain growth. The temperature required to anneal steel depends on the type of annealing to be achieved and the constituents of the alloy.[10]
Quenching and tempering first involves heating the steel to the austenite phase then quenching it in water or oil. This rapid cooling results in a hard but brittle martensitic structure.[8] The steel is then tempered, which is just a specialized type of annealing, to reduce brittleness. In this application the annealing (tempering) process transforms some of the martensite into cementite, or spheroidite and hence reduces the internal stresses and defects. The result is a more ductile and fracture-resistant steel.
Annealed, Quenched and Tempering , Normalized are available , and can be according to definite requirements .