Heat treatment carbonitriding process is frequently used because it can effectively improve the depth of carburizing layer, obtain high hardness, ensure fine austenite grain, reduce part deformation, improve gear strength and wear resistance within a given time. Harbin North Special Vehicle Manufacturing Co., Ltd. has continuously studied the heat treatment carbonitriding process and applied it to the production of tank gears, which has been popularized and applied in China. The gear branch of Jiangxi tractor factory has improved the gas carbonitriding composite catalytic heat treatment process for the two shaft 20crm NTI steel gear of tractor gearbox, which has been applied in industrial production.
Youichi Watanabe and others developed a new transmission gear steel with high strength by heat treatment carbonitriding process under certain process parameters. As the carburizing process is used for a long time, the carburizing process is not easy to obtain the stable performance of a few gears, and only the carburizing process is used for a long time.
In recent years, with the popularization of vacuum carburizing equipment, vacuum carbonitriding technology has gradually developed. The emergence of this technology not only expands the range of materials that can be treated by the vacuum furnace, but also reduces the deformation of parts and improves the wear and corrosion resistance of parts, so as to greatly improve the product quality and solve the problems of high energy consumption and toxic waste gas emission of gas carbonitriding.
At present, the development of rare earth catalytic infiltration process has effectively solved the problem of long production cycle of heat treatment carbonitriding process, and the vacuum heat treatment rotating cup with vacuum carbonitriding function has formed a series of commercialized products and put them into the market. It is believed that with the improvement of process equipment, the heat treatment carbonitriding process will be more widely used.