Hardening is a heat treatment in which steel is rapidly cooled from the austenite phase (temperature about 723 ° C) in order to prevent the formation of pearlite or ferrite. The result is a martensitic structure, which is characterized by its intensive hardness.
The hardening process is followed by relaxing or annealing giving the steel a certain degree of toughness. This method is applied in precision components, precision engineering, tools for hot and cold working and other highly stressed components.
Tempering is performed after hardening annealing at very high temperatures (up to 700 ° C). The aim of annealing is to give the steel a very high strength combined with high toughness. Annealing is particularly recommended for components that are exposed to sudden forces, and safety components which have to withstand a very high deformation.
Crucial to the success of the refining treatment is the uniform heating of the parts to the prescribed curing temperature with a satisfactory quenching and accurate uniformed tempering.