The main cause of rust in pulley bearings
1) In the grinding process, the high temperature of the instantaneous pulley will make the surface of the workpiece reach a molten state, and the steel surface will chemically react with the oxygen in the air, which will form an extremely thin (20--30nm) iron oxide film. If it is not completely removed in the subsequent processing, even if the bearing is coated with anti-rust oil, the internal corrosion will appear on the surface of the bearing after a period of time.
2) When the bearing is refined or over-researched, it does not achieve the specified accuracy, and a certain depth of pit is formed on the surface, and once the corrosion particles or moisture in the air enter these pits, the corrosion will gradually appear.
3) After bearing acid printing and engraving, if the cleaning is not clean or neutralized thoroughly, it will cause corrosion.
4) The way to apply anti-rust oil is unreasonable. One is to use a rag impregnated with anti-rust oil, the bearing on this rag rolling method, sweat on the hand, corrosion on the rag and the bearing part that the anti-rust oil has not been coated will cause corrosion; the second is to stack the bearings together, and then spray the anti-rust oil with a sprayer, and it is difficult to be drizzled with anti-rust oil between the bearing and the superimposed surface of the bearing, so that the corrosion will slowly occur in contact with moisture and oxygen in the air for a long time.
5) Effects of humidity. The critical humidity of steel is about 65%, but many small-scale manufacturers, the humidity of the production environment is mostly more than 65%, and some even reach 80%, which can easily cause rust in the bearing.
