Due to different bearing types, bearing size and different application conditions and other factors, the bearing components will choose different materials, such as bearing steel GCr15SiMn, or carburized steel G20Cr2Ni4A, etc., in the manufacturing process, there are usually forging, turning, heat treatment, grinding, assembly and other processing processes. In order to make bearings more durable, longer life, higher reliability, suitable for more stringent working conditions and other technical requirements, with the continuous emergence and development of new process technology, surface treatment technology of bearing working surface has also been widely used. Commonly used bearing surface treatment technology includes surface physical deformation treatment, chemical treatment, heat treatment, surface film coating treatment and other process methods.

Bearing surface physical deformation treatment method

The use of mechanical treatment process method to make the bearing surface plastic deformation, the formation of high strength and high hardness, high density of hardened layer, this physical deformation strengthening treatment is also known as deformation strengthening or work hardening, commonly used process methods are: shot blasting, sandblasting, polishing, polishing, super fine.

By mechanical extrusion deformation treatment of bearing surface, the increase of dislocation density, the refinement of subcrystalline structure, the enhancement of surface hardness and strength, can significantly improve the surface fatigue strength of parts. At the same time, sand blasting can eliminate the surface stress and reduce the occurrence of heat treatment cracks; Polishing and superfinishing can reduce the surface roughness, improve the surface microstructure, and improve the fit between components and the oil film quality in the rolling area of the bearing. The physical deformation surface strengthening method has the advantages of simple process, remarkable effect and easy process quality control.

Chemical treatment mode

The method of using the solid infiltration of some element to change the chemical composition of the bearing surface layer and achieve surface strengthening is called chemical heat treatment strengthening or diffusion heat treatment. Including chromizing, carburizing, carbonitriding, sulfide and sulfur nitrogen carburizing, graphitized layers, etc., infiltrate elements or dissolve into base metals to form solid solutions, or form compounds with other metal elements. Commonly used carburized steel heat treatment process, bearing surface hardness and high carbon chromium bearing steel the same, the heart is soft, carburizing layer depth is generally 0.8~3.5 mm, surface hardness HRC58~64, core hardness HRC32~48, carburized steel has high hardness, high wear resistance, high contact fatigue strength, good toughness characteristics, It is widely used in the harsh environment of high impact load in metallurgy and other industries.

Bearing surface blackening modification treatment, the use of parts in a strong alkali solution heating, surface oxidation process, so that the bearing surface to produce a layer of dense, and firmly combined with the matrix of iron oxide film. The purpose of blackening treatment is to make the bearing have good anti-rust and anti-corrosion performance, high wear resistance, self-lubrication performance, the surface is shiny and beautiful, and blackening heating helps to reduce internal stress. Retainer phosphating and bearing parts pickling are also blackening processes.

Surface heat treatment method

Surface heat treatment uses solid phase change, through the rapid heating method, the bearing surface layer is quenched, called surface quenching. Including flame heating quenching, high (medium) frequency induction heating quenching. Features: surface local quenching heating speed, small workpiece deformation, short heating time, high production efficiency, surface oxidation and decarburization slight. Suitable for large bearing surface heat treatment, can improve the impact load resistance of large bearing, and has high wear resistance and contact fatigue strength.

Surface coating treatment

A coating applied to a metal surface by physical or chemical process and a reinforced film with properties different from the base material. Including electroplating, electroless plating (chromium, nickel, silver, etc.) composite plating, brush plating, etc., is characterized by the formation of a film with specific properties on the bearing surface, improving the surface's wear resistance, fatigue resistance, corrosion resistance and self-lubrication performance. The treatment method is also used in the bearing repair scheme.