First, contact fatigue strength
Bearing under the effect of the cycle load, the contact surface is very prone to fatigue failure, i.e. cracking spalling occurs, which is the main form of damage to the bearing. Therefore, in order to improve the service life of bearings, bearing steel must have a high contact fatigue strength.
Second, wear
When the bearing, rings, not only rolling friction occurs between the rolling elements and maintain aircraft, but also sliding friction, so that the bearing parts continue to wear. In order to reduce the wear of the bearing parts, precision bearings maintain stability, long life, bearing steel should have good wear resistance.
Third, the hardness
Hardness is an important quality of bearing quality of contact fatigue strength, wear resistance, have a direct impact on the elastic limit. Bearing steel in use state of hardness generally reach HRC61 ~ 65, in order to make contact with the bearing to obtain a higher fatigue strength and wear resistance.
Fourth, anti-rust properties
In order to prevent the bearing parts and finished products in the processing, storage and use of the process of corrosion rust, requires bearing steel should have good rust resistance.
Fifth, the processing performance
Bearing parts in the production process, to go through a lot of cold, heat processing procedures, in order to meet the high-volume, high efficiency, high quality requirements, bearing steel should have good processing properties. For example, cold and hot formability, machinability, hardenability and so on.
In addition to the basic requirements of bearing steel, but also should reach the appropriate chemical composition, even within the organization, less non-metallic inclusions, standards-compliant internal surface defects and surface decarburization layer does not exceed the specified concentration, etc., these projects have a material standard clearly defined.
Bearing parts commonly used materials are: carbon chromium bearing steel, hardened steel (eg 20Cr2Ni4A, 15Mn, 20Cr2MnMoA), high temperature bearing steel (eg Cr4Mo4V, Cr14Mo4, Cr15Mo4V, W18Cr4V), stainless bearing steel (9Cr18, 9Cr18Mo, 1Cr18Ni9Ti) vacuum degassed steel, magnetic bearing steel, the most commonly used is carbon chromium bearing steel. Carbon chromium bearing steel basic steel has GCr6, GCr9, GCr9SiMn, GCr15, GCr15SiMn, it is the most extensive use of bearing manufacturing industry, the largest amount of steel, have good wear resistance and contact fatigue performance, a more ideal processing performance, with a certain degree of flexibility and toughness.
