In view of the differences of resources and production process conditions in various countries, the gear steel alloy series used are different. For example, Germany adopts Mn CR series (16MnCr5, 20m ncr5, 25mncr5, 27mncr5); Scm-420r and h-420m series are adopted in Japan; The United States adopts Cr Ni Mo series (sae8615, 8620); France adopts Cr Ni series (19cn5) and Cr Mo series (20cd4, 27cd4, 30cd4); Cr Mn series is adopted in China, and 20CrMnTi gear steel is widely used. With the development of automobile industry, the variety and quantity of domestic traditional automobile gear steel and imported steel have increased significantly.
Domestic automotive gear steel has mainly used the steel series of the former Soviet Union for many years. In the 1960s and 1990s, boron steel was widely used in the early stage to save CR resources. In the later stage, according to the requirements of medium and heavy truck gears, a lot of research was invested in Si Mn, Cr Mo and Mn CR series steel, such as sedan cars mainly used to introduce Japanese brands or with technical background of Japanese brands The axle tooth parts of truck gearbox, gear and drive axle are made of steel imitating Japanese JIS standard: SCM420H, SCM822H, and Mn-Cr steel produced according to German Volkswagen enterprise standard, such as 16MnCr5, 20mncr5, 25mncr5, 27mncr5, 29mncr5, which are widely used in Santana, Audi, Jetta and Fukang car gearbox axle tooth parts.
At the end of the 20th century, in order to meet the needs of automobile gear localization, China’s automobile gear steel has successively developed new steel types similar to gear steel in the United States, Germany, Japan and other countries, such as 20mncr5, 16MnCr5, scm4l5, SCM420, SCM 415h, SCM420H, 21nicrm o5h, 20mncr5cab and so on. It is mainly used for gearbox gears of FAW Eaton and Shaanxi fast, as well as IV eco light vehicles and other components. In order to make Automobile Carburized Gear Steel reach the foreign steel level, the key equipment and technology of gear steel production are introduced. At present, domestic special steel companies can organize the production of automobile gear steel according to international advanced standards, such as German standard gear steel 28MnCr5 developed by Laigang Special steel plant.
In the 21st century, free cutting steel, heavy-duty gear steel and carbonitriding steel have become the research direction. For example, the new automobile gear steel 20CrNi2Mo developed for the use of high-power engine can be used for key heavy-duty gears in automobile gearbox. The new gear steel can also be widely used in middle and high-grade car gears and high stress heavy-duty gears in construction machinery. At present, 20CrMnTi is still used most in China’s automobile industry, followed by 20Cr, 20CrMo and 20CrMnMo steel.