The main causes of rust are as follows:
1. In the process of bearing production, some enterprises did not strictly follow the requirements of cleaning and rust prevention procedures and oil seal rust prevention packaging to rust-proof the bearing parts during processing and the assembled bearing products. If the rotation time of the ferrule is too long, the outer circle of the outer ring is in contact with corrosive liquid or gas.
2. The quality of anti-rust lubricants, kerosene and other products used by some enterprises in production does not meet the requirements of process technology.
3. As the price of bearing steel drops, the material of bearing steel gradually declines. Such as the high content of non-metallic impurities in steel (increased sulfur content in steel makes the material itself rust resistance decline), metallographic structure deviation and so on. The sources of bearing steel used by current production enterprises are relatively complex, and the quality of steel is even more mixed.
4. The environmental conditions of some enterprises are poor, the content of harmful substances in the air is high, the turnover site is too small, and it is difficult to carry out effective antirust treatment. Air compressor bearing hardness is one of the important qualities of bearing quality, which has an indirect impact on contact fatigue strength, wear resistance and elastic limit. The hardness of the bearing steel under the application conditions must reach HRC61 ~ 65 individually, the ability to make the bearing achieve higher contact fatigue strength and wear resistance. Coupled with the hot weather, production workers also violated the rust prevention regulations and other phenomena.
5. Some enterprises' anti-rust paper, nylon paper (bag) and plastic tube and other bearing packaging materials do not meet the requirements of rolling bearing oil seal anti-rust packaging is also one of the factors that cause rust.
6. The turning allowance and grinding allowance of bearing rings of some enterprises are relatively small, and the oxide scale and decarburization layer on the outer circle are not completely removed. Under the action of cyclic load, the precision bearing of machine tool will easily cause fatigue damage when it comes into contact with the surface, that is, cracks and spalls will appear. This is an important situation of bearing damage. Therefore, in order to improve the service life of the bearing, the bearing steel must have high contact fatigue strength.