渗硼工艺对汽车发动机轴承用12Cr2Ni3Mo5钢性能的影响  

Effect of boronizing process on properties of 12Cr2Ni3Mo5 steel for automobile engine bearing

作　　者：胡瑞海 冯松[1] 祖润青 何怡 Hu Ruihai;Feng Song;Zu Runqing;He Yi(Changzhou Liu Guojun Branch,Jiangsu Union Technical Institute,Changzhou Jiangsu 213025,China;Wuxi Yingjie Automobile Technology Co.,Ltd.,Wuxi Jiangsu 214063,China;College of Nuclear Technology and Automation Engineering,Chengdu University of Technology,Chengdu Sichuan 610059,China)

机构地区：[1]江苏联合职业技术学院常州刘国钧分院,江苏常州213025 [2]无锡英捷汽车科技有限公司,江苏无锡214063 [3]成都理工大学核技术与自动化工程学院,四川成都610059

出　　处：《金属热处理》2024年第1期268-272,共5页Heat Treatment of Metals

基　　金：2018年江苏省教育信息化研究立项课题(20180108);江苏省社会科学基金(19JYB012);第五期江苏省职业教育教学改革研究课题(ZYB21)。

摘　　要：以汽车发动机轴承用12Cr2Ni3Mo5钢为试验材料,对其渗硼工艺及渗硼后的性能展开研究,分析了渗硼温度850~1000℃、渗硼时间2~6 h条件下渗硼层厚度、硬度分布、耐磨性能和显微组织。结果表明,随着渗硼温度的提高或渗硼时间的增加,渗硼层厚度均增加。当渗硼时间为5 h,随渗硼温度的提高,渗硼层硬度提高且大幅高于基体硬度420 HV0.5,当渗硼温度为1000℃时渗硼层硬度最高达到1520 HV0.5。在磨损时间为60 min时,渗硼温度850、900、950和1000℃下的磨损量分别为4.5、3.2、2.2和2.0 mg,均较未渗硼时的磨损量(11 mg)大幅减少,表明渗硼处理可提高12Cr2Ni3Mo5钢的硬度和耐磨性,但渗硼温度超过950℃、渗硼时间超过5 h后的性能改善效果显著下降,故综合考虑渗硼后的性能和经济成本,渗硼温度950℃、保温时间5 h为12Cr2Ni3Mo5钢的最佳渗硼工艺,此时渗硼层厚度为83μm,硬度最大可达到1432 HV0.5,渗硼层组织主要为Fe_(2)B相。Taking 12Cr2Ni3Mo5 steel for automobile engine bearing as the tested material,the boronizing process and the properties of the steel were studied.The thickness,microhardness distribution,wear resistance and microstructure of the boronizing layer of the steel after boronizing at 850⁃1000℃for 2⁃6 h were analyzed.The results show that the thickness of borided layer increases with the increase of boronizing temperature or boronizing time.When the boronizing time is 5 h,the hardness of the boronizing layer increases with the increase of boronizing temperature,which is much higher than the substrate hardness of 420 HV0.5.When the boronizing temperature is 1000℃,the hardness of the boronizing layer reaches a maximum of 1520 HV0.5.When the wear time is 60 min,the wear mass loss of the steel is 4.5,3.2,2.2 and 2.0 mg at boronizing temperature of 850,900,950 and 1000℃,respectively,which is significantly lower than that without boronizing(11 mg),indicating that the boronizing treatment can improve the hardness and wear resistance of the 12Cr2Ni3Mo5 steel.However,when the boronizing temperature exceeds 950℃and the boronizing time exceeds 5 h,the improvement effect decreases significantly.Therefore,considering the property after boronizing and economic cost of boronizing process,the boronizing temperature of 950℃and the holding time of 5 h is the best boronizing process for the 12Cr2Ni3Mo5 steel.Under this process,the thickness of the boronizing layer is 83μm,the maximum hardness can reach 1432 HV0.5,and the microstructure of the boronizing layer is mainly Fe_(2) B phase.

关 键 词：渗硼工艺 汽车轴承钢 显微硬度 耐磨性 

分 类 号：TG146.15[一般工业技术—材料科学与工程]