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FAG bearings and bearing steel smelting quality of life and reliability have a close relationship, to a large extent. As regards the characteristics and bearing steel, iron and steel making industry is much more rigid than the average quality requirements, such as steel, chemical composition, purity, uniformity and organization.
Major metallurgical requirements have the following several points:
1 strictly chemical composition requirements
FAG bearings for steel is high carbon chromium bearing steel, carbon content of around 1%, joining 1. 5% about chromium and eutectoid steel containing small amounts of manganese, Silicon. Heat treatment for chromium may improve performance, increase the hardenability, homogeneous, tempering stable and rust resistance of steel, and grinding performance. However, when the chromium content of more than 1. 65%, increased residual austenite in steel after quenching and lower hardness and dimensional stability, increase the nonuniformity of carbide, reducing the impact toughness and the fatigue strength of steel.
2, high-precision size requirements
Rolling bearing steels require higher dimensional accuracy of steel, this is because most of the bearing parts are subject to pressure. In order to save on materials and enhanced productivity, most bearing rings is through forging, steel ball was cold or hot forming, the small size of the rollers through cold forming. If steel dimensional accuracy is not high, it is impossible to accurately calculate cutting dimensions and weight, and cannot guarantee the product quality of bearing parts, equipment and mold damage is also easy.
3, particularly stringent purity requirements
Purity is of steel containing non-metallic inclusions in steel, high purity, non-metallic inclusions in steel by less. Bearing oxides, silicates, such as inclusions in steels are leading to early fatigue spalling in bearing, significantly reducing major causes of bearing life. Worst especially brittle inclusions, as easily from metal on the substrate in the process comes off, seriously affecting the part after finishing of the surface quality of FAG bearings. Therefore, in order to increase bearing service life and reliability, must reduce the concentration of inclusions in bearing steel.
4 strictly macrostructure and microstructure (high organizational requirements)
Bearing steel in the macrostructure refers to General loose, loose and flat body of the Centre, microscopy (high power organizations, including the Organization for annealing of steel, mesh, Ribbon and fluid of carbide, etc. Fluid analysis of carbide hard and brittle, its harmfulness and brittle inclusions of the same. Network Carbide to reduce impact toughness of steels, and organization of non-uniform, easily when the quenching deformation and cracking. Ribbon effects of annealing and quenching and tempering of carbide organization as well as contact fatigue strength. Low, high power pros and cons of rolling bearing performance and life of your organization has a significant impact, so bearing materials for low standards, the high has strict requirements of your organization.
5, particularly stringent requirements for surface defects and internal defects
FAG bearing steel, surface defects include cracking, oxidation of slag, Burr, scarring, skin and so on, including cratering, sparkling, white, serious internal defects, porosity and segregation. These deficiencies for the machining of bearings, bearing performance and life have a lot of influence, clearly in the bearing material standards these defects are not allowed.
6, carbide nonuniformity of the particularly stringent requirements
In bearing steel, if a serious uneven distribution of carbides, the heat treatment process on microstructure and hardness of lead in non-uniform, tissue inhomogeneity on contact fatigue strength of steels has a larger impact. In addition, the nonuniformity of carbide is also easy to make serious bearing parts in quench cracks, nonuniformity of carbide will also lead to reduced life expectancy of FAG bearings, bearing material standard, different specifications of special requirements for steel are clear.
7, decarburized layer on the surface of the particularly stringent requirements
In the material standard FAG bearings on steel surface decarburization layer has strict rules, if the surface decarburization layer exceed the specified limits, and in front of the heat treatment process and it is not clear all are prone to quenching crack in the quenching process, part of the scrap.
8, additional requirements
FAG bearings in standard steel materials on oxygen content in bearing steel smelting method, hardness, fracture, annealing, residual elements, spark inspection, delivery status, and identity have strict requirements.
| Product Model | Inside Diameter | Outside Diameter | Thickness |
| 4T-30305 NTN | 25 | 62 | 17 |
| 4T-33205 NTN | 25 | 52 | 22 |