The purpose of the study is to develop a technology for vacuum carburization of heat-resistant steels, taking into account the requirements for the structure of the carburised layer to ensure the operational properties of gears. The paper describes the issues of improving the operating characteristic of heavily loaded gears made of high-strength steels. Information on the modes of vacuum cementation is given. A technological process has been developed that ensures the presence of carbides on the tooth profiles, the absence of a carbide mesh in the cemented layer and the optimal mechanical properties of the gears. Recommendations on the choice of modes of diffusion saturation to ensure wear resistance, contact endurance, bending strength of gears made of heat-resistant steels are proposed.