Characteristics of bearing steel:
1. Contact fatigue strength
Under the action of cyclic load, the contact surface of the bearing is prone to fatigue damage, that is, cracking and peeling, which is the main damage form of the bearing. Therefore, in order to improve the service life of the bearing, the bearing steel must have a very high contact fatigue strength.
2. Wear resistance
When the bearing is working, not only rolling friction but also sliding friction occurs between the rings, rolling elements and cages, which causes continuous wear of the bearing parts. In order to reduce the wear of bearing parts, maintain the stability of bearing accuracy and extend the service life, bearing steel should have good wear resistance.
3. Hardness
Hardness is one of the important qualities of bearing quality, which has a direct impact on contact fatigue strength, wear resistance and elastic limit. The hardness of bearing steel under use conditions should generally reach HRC61~65, so that the bearing can obtain higher contact fatigue strength and wear resistance.
4. Anti-rust performance
In order to prevent bearing parts and finished products from being corroded and rusted during processing, storage and use, the bearing steel is required to have good anti-rust performance.
5. Processing performance
During the production process, bearing parts have to go through many cold and hot processing procedures. In order to meet the requirements of small quantity, high efficiency and high quality, bearing steel should have good processing performance. For example, cold and hot forming performance, cutting performance, hardenability, etc.
In addition to the above basic requirements, bearing steel should also meet the requirements of appropriate chemical composition, uniform internal structure, less non-metallic impurities, external surface defects meeting the standards, and surface decarburization layer not exceeding the specified concentration.