Heat treatment

Heat treatment

All necessary protocols, diagrams, and the quality control report will be submitted to you concerning the performed heat treatment

toplotna obdelavaHeat treatment is a set of processes by means of which materials are heated to a certain temperature and are then (after a certain period of time) once again cooled. The heating phase is called austenitizing and the cooling phase is the transformation of austenite into structures, such as martensite, bainite, and pearlite. These structures form by means of various cooling rates.

Heat treatment consists of heating steel to austenitizing temperature and then cooling at a suitable rate. Carbon steel and simple workpieces may be placed directly into the furnace which has been heated to a suitable temperature, and alloy steel may be heated in stages in order to avoid the deformation and fracture of workpieces.

During annealing at austenitizing temperature, homogeneous austenite is formed. If the annealing process is carried out at an excessive temperature or for too long, large crystal austenite grains are formed which have a negative effect on the mechanical properties.

Annealing is followed by cooling which must be sufficiently rapid in order for the austenite to transform into martensite by means of diffusionless transformation. Carbon and other alloy constituents must remain dissolved. This significantly hardens steel. The necessary cooling rate depends on the type of steel.

Carbon steel is hardened in water or oil, while alloy steel begins hardening as soon as it is in contact with air. The hardening of steel is followed by tempering in order for the required properties to be achieved.