With the development of science, gears have slowly changed from metal gears to plastic gears. Because plastic gears are more lubricating and wear-resistant. Can reduce noise, reduce costs, reduce friction.
Commonly used plastic gear materials are: PVC, POM, PTFE, PA, nylon, PEEK, etc.
There are many steel grades for medium and heavy-duty truck gears in my country, mainly to meet the requirements of introducing advanced foreign automobile technology at that time. In the 1950s, my country introduced the production technology of Soviet medium-sized trucks (ie, the original “Jiefang” brand) from the former Soviet Union’s Rikhachev Automobile Factory, and also introduced the 20CrMnTi steel grade of the former Soviet Union to produce automobile gears.
After the reform and opening up, with the rapid development of my country’s economic construction, in order to meet the needs of the rapid development of my country’s transportation, since the 1980s, my country has introduced various advanced models from industrially developed countries in a planned way, and various foreign advanced medium and heavy duty vehicles. Trucks are also being introduced. At the same time, my country’s major automobile factories cooperate with famous foreign automobile companies to introduce foreign advanced automobile production technology, including the production technology of automobile gears. At the same time, the level of iron and steel smelting technology in my country is constantly improving. The use of advanced smelting technologies such as secondary ladle smelting, fine-tuning of components, continuous casting and rolling enables steel mills to produce gears with high purity, hardenability and narrowing. By using steel, the localization of imported automobile gear steel has been realized, which has brought the production level of my country’s gear steel to a new level. The domestic nickel-containing high hardenability steel for heavy-duty automobile gears suitable for my country’s national conditions has also been applied and achieved good results. The heat treatment technology of automobile gears has also developed from the original use of well-type gas carburizing protection in the 1950s and 1960s to the current widespread use of computer-controlled continuous gas carburizing automatic lines and box-type multi-purpose furnaces and automatic production lines (including low-pressure (vacuum) carburizing. technology), gear carburizing and pre-oxidation treatment technology, gear quenching control cooling technology (due to the use of special quenching oil and quenching cooling technology), gear forging blank isothermal normalizing technology, etc. The adoption of these technologies not only effectively controls the gear carburizing and quenching distortion, improves the gear machining accuracy, and prolongs the service life, but also meets the mass production needs of modern heat treatment of gears.
Relevant literature points out that the life of automobile gears is mainly assessed by two indicators, one is the contact fatigue strength of the gears, and the other is the bending fatigue strength of the gears. The former is mainly determined by the quality of carburizing and quenching, and the latter is mainly determined by the gear material. To this end, it is necessary to have a more comprehensive understanding of the requirements, properties and heat treatment characteristics of carburized steel for automobile gears.
Post time: Jun-17-2022