1. The intensity of contact fatigue
Under the action of cyclic load, the bearing is easily exposed to fatigue damage, that is, cracking and spalling, which is an important damage situation of the bearing. Therefore, in order to improve the service life of the bearing, the bearing steel must have a high contact fatigue strength.
2. Wear resistance
In the bearing task, not only the rolling friction between the ferrule, the rolling element and the maintenance frame occurs, but also the sliding friction occurs, so that the bearing parts are always worn. In order to increase the wear of the bearing parts, maintain the bearing accuracy and stability, and extend the service life, the bearing steel should have good wear resistance.
3. The hardness
Hardness is one of the important qualities of bearing quality and has an indirect effect on contact fatigue strength, wear resistance and elastic limit. The hardness of the bearing steel in the application condition has to reach HRC61~65, which makes the bearing achieve high contact fatigue strength and wear resistance.
4. Anti-rust performance
In order to avoid corrosion and rust of bearing parts and finished products during processing, storage and operation, it is required that bearing steels should have good rust prevention performance.
5. Processing performance
In the course of consumption, bearing parts have to go through many cold and hot processing steps. In order to satisfy the request of small amount, high efficiency and high quality, bearing steel should have good processing performance. For example, cold, thermoforming properties, machinability, hardenability, and the like.
In addition to the above basic requirements, the bearing steel should also reach the requirements of proper chemical composition, average external organization, less non-metallic inclusions, external appearance defects, and external decarburization layer not exceeding the regulatory concentration. These names are in the original data specifications. Clear rules.
The rare parts of the bearing parts are: high carbon chromium bearing steel, carburized steel (such as 20Cr2Ni4A, 15Mn, 20Cr2MnMoA), low temperature bearing steel (such as Cr4Mo4V, Cr14Mo4, Cr15Mo4V, W18Cr4V), stainless bearing steel (9Cr18, 9Cr18Mo, 1Cr18Ni9Ti ), vacuum degassing steel, anti-magnetic bearing steel, etc., the most rarely used is high carbon chromium bearing steel. The basic steel grades of high carbon chromium bearing steels are GCr6, GCr9, GCr9SiMn, GCr15, GCr15SiMn, which is the most widely used and most used steel in the bearing manufacturing industry in China. It has good wear resistance and contact fatigue performance. Fantasy processing performance with a certain degree of flexibility and toughness.