Heat treatment effect on 20cr14co12mo5 bearing steel

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With the development of the aerospace technology at home and abroad, the bearing material is faced with high speed, high Hertz stress, the demand such as heat resistance, corrosion resistance, and weight loss, more and more high to the requirement of bearing material all aspects of performance, especially the strong performance as a direct result of the rapid development of the ultra-high strength of bearing, gear steel, a new generation of high strength and ultra-high strength bearing, gear steel all secondary hardening theory is used to design. 20 cr14co12mo5 bearing steel with low carbon martensite and secondary hardening mechanism design, has high tensile strength, fracture toughness and corrosion resistance, and certain heat-resisting performance. How heat treatment, the mechanical properties of test steel plays an important role, Slovenia V.L ESKOVSEK of cryogenic treatment after tempering hardness increase slightly again tempering hardness, made the steel in the second after tempering toughness increased at the same time, the surface hardness can meet the requirements. Material of iron and steel research institute institute researchers studied 20 cr14co12mo5 high-performance bearing steel heat treatment process on the organization and the influence law of strong performance.Heat treatment effect on 20cr14co12mo5 bearing steel Experiment with 20 cr14co12mo5 steel main ingredients are shown in table 1, after dealing with the VIM + VAR, cast 100 kg ingot, the high temperature forging into phi 20 mm bar. With rockwell hardness tester, hardness HR150A type average value of each sample for five point hardness; Tensile specimen size (mm) as the phi 5 x 65 standard sample, each data are averages of three sample; Impact of sample size (mm) for 10 x 10 x 55, u-shaped notch; Fracture toughness specimen size (mm) is a 20 x 40 x 180, fracture toughness test for MTS880 universal mechanical testing machine. 20 cr14co12mo5 bearing steel at 1050 ?, 1050 ?, 1050 ? temperature quenching, after cold treatment using the tempering temperature is 500 ?, tempering time for 3 h. After 1100 ? quenching treatment and cold treatment, with 490 ? respectively x 2 h, 490 ? by 3 h, 500 ? tempering system x 3 h.Heat treatment effect on 20cr14co12mo5 bearing steel The results are as follows: 1) double ultra clean vacuum smelting preliminary developed A 20 cr14co12mo5 ultra strong toughness, heat corrosion resistant bearing steel, by controlling the phase transition, achieve the Rm of 1840 mpa, Rp0.2 is 1410 mpa, A 17%, Z is 62.5%, Aku j. 75 cm 2, KIc is 108 mpa, m1/2, etc.Heat treatment effect on 20cr14co12mo5 bearing steel 2) by analyzing the changes of bearing steel strength and toughness, found that the solid solution strengthening, ultra refined martensite lath, small and strengthening phase of dispersion distribution of Laves phase and M2C and M23C6 carbides and a small amount of residual austenite is an important factor of bearing steel is strong. 3) by analyzing the different heat treatment processes on the influence of hardness and impact toughness, found that cold treatment has significant effects on hardness and impact toughness of steel; Tempering a significant increase in material hardness for the first time, while smaller influence on impact toughness.Heat treatment effect on 20cr14co12mo5 bearing steel