1、 Contact fatigue strength
Under the action of periodic load, the contact surface of the bearing is easily damaged by fatigue, that is, cracks and spalling emerge, which is an important damage situation of the bearing. Therefore, in order to improve the service life of bearings, bearing steel must have high contact fatigue strength.
2、 Wear resistance
When the bearing works, not only rolling friction but also sliding friction will occur between the rings, rolling elements and maintenance frames, so that the bearing parts will be worn all the time. In order to increase 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 indirect influence on contact fatigue strength, wear resistance and elastic limit. The hardness of bearing steel under application conditions shall reach HRC61~65, which enables the bearing to obtain high contact fatigue strength and wear resistance.
4、 Rust resistance
In order to prevent bearing parts and finished products from being corroded and rusted during processing, storage and operation, it is required that bearing steel should have good rust resistance.
5、 Processability
In the course of consumption, bearing parts have to go through many cold and hot working 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 properties, machinability, hardenability, etc.
In addition to the above basic requirements, the bearing steel shall also meet the requirements of proper chemical composition, average external structure, less non-metallic impurities, external surface defects conforming to the specification, and external decarburization layer not exceeding the regular concentration.
