The carburising process not only improves surface hardness, wear resistance and continuous strength, but also improves the strength and ductility of the core area of the part. In this way, it is ensured that large loads are carried and impact loads are met.

The carbon content of carburising materials is generally between 0.10 - 0.20 %, in some varieties it can reach up to 0.25 %. They can be produced as alloyed or unalloyed.

Carburising steels can be subjected to heat treatment in different ways after carburising. After the carburising process, the amount of carbon in the core region remains at 0.10 - 0.20 %, while the amount of carbon in the surface region increases up to 0.8 %. In this case, the selection of the heat treatment temperature becomes difficult due to the varying amount of carbon in all parts of the part structure. The temperature to be selected based on the core region leads to grain coarsening in the part wall region, and the temperature to be selected based on the part wall region leads to insufficient hardening of the core region. For this reason, the easiest method that can be applied is direct hardening from the carburising temperature. This method can only be applied after salt bath and gas carburising. The method is more suitable for fine grain steels.