1.7139 (16MnCrS5)

The steel can be supplied with a sulfur content of 0.020−0.040%. Carburization can be carried out in solid (powdery), liquid or gaseous media. In general, there are two methods: simple and direct hardening after carburization. When hardening, the carburized material is cooled to room temperature or at least 600 ° C., after which it is heated to the quenching temperature, which usually exceeds the point Ac-3. The carburizing temperature at simple hardening is always higher than the hardening by 50−100 ° C. With direct quenching, the stage of cooling and heating of the material to the quenching temperature is excluded. In this case, direct cooling from the carburizing temperature is used. In direct hardening, only fine-grained steels and some alloys are used to avoid the formation of residual austenite.