High prime steel is also a high temperature bearing steel

Bearing steel is suitable for making rolling bearing ball, roller, needle and bearing inner and outer rings of the alloy steel. China's steel number before adding G said. Bearings are subjected to great pressure and friction when working, so bearing steel is required to have high and uniform hardness and wear resistance, as well as high elastic limit. The uniformity of the chemical composition of bearing steel, the content and distribution of non-metallic inclusions, the distribution of carbide, etc. are very strict requirements, is one of the strict requirements of all steel production. Technical standards bearing steel production mainly implement GB/T18254-2002 standard and adapt to the requirements of users of precision forging bearing Lai Steel GCr15JD quality agreement, which GCr15JD agreement quality requirements than GB/T18254-2002 standard, GCr15JD requires oxygen content ≤ 10ppm, central segregation level ≤ 1.0 grade, composition control, sizing and Size deviation, etc. are stricter than the GB/T18254-2002 standard.

The main types of China has produced high-carbon chromium stainless bearing steel, the main steel grade 9Cr18; carburized bearing steel, the main steel grade G20CrMo; chromium bearing steel, the main steel grade GCr15. bearing steel, also known as high-carbon chromium steel, carbon content ωc for about 1%, chromium content ωcr for 0.5%-1.65%. Bearing steel is also divided into six categories: high-carbon chromium bearing steel, chromium-free bearing steel, carburized bearing steel, stainless bearing steel, medium and high temperature bearing steel and anti-magnetic bearing steel; metallurgical quality performance 1) high contact fatigue strength, 2) after heat treatment should have high hardness or hardness that can meet the requirements of bearing performance, 3) high wear resistance, low friction coefficient, 4) high elastic limit, 5) good impact toughness and fracture toughness, 6) good dimensional stability, 7) good antirust properties, 8) good cold and hot processing performance. Smelting quality requirements 1) strict chemical composition requirements. 2) higher dimensional accuracy requirements, for the use of hot-rolled annealed bars forged on high-speed header, should have higher requirements for its dimensional accuracy. 3) particularly strict purity requirements. 4) strict low-frequency organization and microscopic (high-frequency) organization requirements. 5) particularly strict surface defects and internal defects requirements. 6) strict carbide inhomogeneity requirements. 7) strict surface defects and internal defects requirements. (7) strict surface decarburization layer depth requirements. Physical properties of bearing steel physical properties are mainly to check the microstructure, decarburization layer, non-metallic inclusions, low times the organization. In general are delivered in hot-rolled annealed, cold-drawn annealed. Delivery condition should be specified in the contract. The low-frequency organization of the steel must be free of shrinkage, subcutaneous bubbles, white spots and microscopic porosity. The central laxity and general laxity shall not exceed 1.5 grade, and the deviation shall not exceed 2 grade. Annealing organization of the steel should be uniformly distributed fine-grained pearlite. Decarburization layer depth, non-metallic inclusions and carbide unevenness should be in line with the relevant national standards.