Content of BEARING in our journal

Published in last 1 year |  In last 2 years |  In last 3 years |  All Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select New material for aerospace bearing:60NiTi alloy Zhang Jiahua, Xiao Fei, Wang Jianzhong, Xu Zhongjun, Jin Xuejun Heat Treatment of Metals    2021, 46 (6): 1-7.   doi:10.13251/j.issn.0254-6051.2021.06.001 Abstract （285）      PDF （899KB）（280）       Knowledge map    Among the large family of NiTi alloys, the NiTi alloy with equal atomic ratio have shape memory effect and super elasticity, Compared with NiTi alloy, thermoelastic martensitic transformation does not occur in the 60NiTi alloy, and it has no shape memory effect and super elasticity. However it has outstanding potential in hardness, corrosion resistance and elastic properties, showing a good application prospect in the aerospace field. The solid solution treated 60NiTi alloy also has structural stability, super corrosion resistance and excellent wear resistance, and has become a candidate new material for aerospace bearings. Reference | Related Articles | Metrics Select Effect of tempering temperature on microstructure and mechanical properties of high nitrogen stainless bearing steel Wang Lingqi, He Yanlin, Pan Le Heat Treatment of Metals    2021, 46 (6): 8-13.   doi:10.13251/j.issn.0254-6051.2021.06.002 Abstract （285）      PDF （616KB）（243）       Knowledge map    Microstructure and mechanical properties of high nitrogen stainless bearing steel Cronidur 30 with different tempering temperature were studied and analyzed by universal tensile testing machine, impact testing machine, OM, X-ray diffraction, SEM and TEM, etc. The results show that the microstructure is tempered martensite, carbonitride and retained austenite after tempering at 150-500 ℃. When the tempering temperature exceeds 550 ℃, the microstructure is tempered sorbite, and the precipitated phase gradually gathers and grows. With the tempering temperature increase, the hardness and the tensile strength first decrease, then increase, finally decrease, the impact toughness behaves on the contrary. Secondary hardening occurs because of M23C6 and Cr2N increase when tempered at 450 ℃, and the tensile strength is 2133 MPa. After tempered at 400 ℃, the precipitated phases (σ phases) which riched in Cr-Fe-Mo is observed slightly, reduces impact toughness observably. When tempered at 500 ℃, the impact toughness slightly decreases because of the translation of retained austenite. Reference | Related Articles | Metrics Select Comparative analysis of high performance bearing steels Li Xiong, Lin Faju, Du Simin, Wu Chengchuan Heat Treatment of Metals    2021, 46 (6): 14-20.   doi:10.13251/j.issn.0254-6051.2021.06.003 Abstract （191）      PDF （614KB）（139）       Knowledge map    Several kinds of high performance bearing steels were compared and analyzed. The results show that the strengths of carburized bearing steels are lower than that of through-hardened bearing steels, but the ductility and toughness are higher. Only the hardness of CSS-42L and M62 steels reaches 68 HRC among the current steel grades, which means that it has greater dynamic load-bearing capacity. High chromium Cr-Mo-V(Co) bearing steels have better hot hardness than other steels, and hot hardness of CSS-42L and M62 steels at 500 ℃ exceed 58 HRC. The hardness profiles of P675, Ferrium C61 and M50NiL are better than CSS-42L. Although CSS-42L steel has a high surface hardness, there is “concave area” in the hardness profile of the carburized layer, which limits its use under high load conditions. Corrosion resistance is the most important index affecting bearing life. The corrosion resistances of Cronidur 30 and Pyrowear 675 are better than that of CSS-42L and M50NiL. In addition to CSS-42L steel, the volume percent of retained austenite in bearing steels used above 350 ℃ is less than 10%. There are too many retained austenite in CSS-42L steel, which will affect the dimensional stability due to the transformation of austenite under the action of temperature and load when used at high temperature, so CSS-42L steel is limited applicating in aerospace field. Now only M62 and ASP2060 steels can be used as bearing above 500 ℃. Carburizing/nitriding can generate residual compressive stress on the steel surface, which is beneficial to improve the fatigue life. The subsurface compression stresses of P675 and M50NiL steels are greater than that of CSS-42L steel. Although the fatigue life of the CSS-42L steel tested by the ball-on-rod tester is approximately twice that of the Pyrowear 675 steel, the fatigue life of the Pyrowear 675 steel is higher than that of the CSS-42L steel when the lubrication is insufficient in the high-load accelerated test of the bearings. Reference | Related Articles | Metrics Select Effects of post-quenching cleaning and cold treatment process on retained austenite content of 9Cr18 steel bearing ring An Min, Fu Zhongyuan, Yuan Chao, Xia Yunzhi Heat Treatment of Metals    2021, 46 (6): 21-23.   doi:10.13251/j.issn.0254-6051.2021.06.004 Abstract （144）      PDF （613KB）（114）       Knowledge map    Effects of cleaning process after oil quenching, subzero treatment process and interval between cleaning and subzero treatment on the final retained austenite content of 9Cr18 steel bearing ring were analyzed in view of the same quenching and tempering conditions. The results show that the higher the cleaning temperature after oil quenching, and the longer the interval between cleaning and subzero treatment, the higher the retained austenite content. However, the content of retained austenite increases when the temperature of subzero treatment is much too low, so the recommended subzero treatment temperature should be between －70 ℃ and －80 ℃. Reference | Related Articles | Metrics Select Influence of oil groove mechanism of mesh belt furnace on taper distortion of deep groove ball bearings Wang Tao, Zhao Kang Heat Treatment of Metals    2021, 46 (6): 24-26.   doi:10.13251/j.issn.0254-6051.2021.06.005 Abstract （89）      PDF （614KB）（70）       Knowledge map    Mesh belt furnace is often used for heat treatment of deep groove ball bearings. The structure of mesh belt furnace oil groove, viscosity of quenching oil and cooling rate have great influence on the quenching distortion of bearings. Based on 6206/01 bearing ring, the mechanism of taper distortion was discussed. The results show that the taper distortion of bearing ring in heat treatment has a great correlation with the uniformity of quenching and cooling. When the turnover speed of small mesh belt is adjusted to 15 s, the uniformity of quenching and cooling of bearing ring can be improved, and the taper distortion of 6206/01 bearing ring can be better controlled. It can also be used for reference to other specifications of bearing rings. Reference | Related Articles | Metrics Select Comparative analysis of evaluation standards of carbide network in high carbon chromium bearing steel Zhuang Quan, Wang Yutian, Dong Zhipeng Heat Treatment of Metals    2021, 46 (6): 27-30.   doi:10.13251/j.issn.0254-6051.2021.06.006 Abstract （138）      PDF （621KB）（102）       Knowledge map    By comparing GB/T 18254—2016 and SEP 1520-1998 of two carbide network evaluation standards, the impact of the difference in rating magnification, rating picture pedigree and rating principles on quality judgment was analyzed. The results show that compared with the GB/T 18254—2016 standard, the map setting, detection and evaluation methods of the SEP 1520-1998 standard reflect the physical level more comprehensively and are more operable. At the same time, it is proposed that due to the difference in the cooling rate of the surface layer and the core of large bearing member, the control requirements for the grade of carbide network on the surface and in the center should be separately proposed according to the effective thickness. Reference | Related Articles | Metrics