Koyo one-way bearing selects the material corrosion problem solving method

In order to make the koyo bearing parts quenching tempering after large surface residual compressive stress, could pass infiltration during quenching heating carbon or nitriding atmosphere, on the surface carburizing or nitriding for a short period of time. Because the steel quenching when heated austenitic actual carbon content is not high, far lower than on the phase diagram shows the equilibrium concentration, so it can absorb carbon ( Or nitrogen) 。 When austenite contains higher carbon or nitrogen, the Ms is reduced, quenching surface when the martensitic transformation in the aftermath of the inner layer and center, produce the large residual compression stress. GCrl5 steel by carburizing atmosphere and the atmosphere carburizing quenching ( Both low temperature tempering) After treatment, the contact fatigue test, you can see that the surface carburizing of life than carburized increased 1. 5 times. The reason for carburizing of the surface of the parts has a larger residual compressive stress. 1, metal surface finish ( The oxygen concentration cell corrosion) 。 2, metal material chemical composition and the structure itself. 3, contact with the metal surface composition and pH value of solution. 4, the environment temperature and humidity. 5, the various environmental medium metal surfaces in contact with. 6, the other person's sweat is also causes of koyo bearing corrosion, its pH value of 5 ~ 6. So in order to prevent hand sweat cause corrosion, installation and production personnel should wear gloves, don't literally hand contact bearing.