Carburizing is generally aimed at steel. The carburizing of steel is heating and heat preservation of the steel in the carburizing medium, so that carbon atoms penetrate into the surface of the steel, so that the carbon concentration on the surface changes, so as to obtain a certain surface carbon content and Heat treatment process with a certain concentration gradient.

The purpose of carburizing is to obtain high surface hardness, wear resistance and high contact fatigue strength and bending fatigue strength of machine parts.

Carburizing can be divided into three types: solid carburizing, liquid carburizing, and gas carburizing according to the aggregation state of the infiltrating agent.