摘要
近年来,为追求更优异的滚动接触疲劳性能,表面渗碳技术已被广泛应用于轴承钢的制备过程中。本工作对一种高强不锈轴承钢进行两种不同工艺时长的渗碳处理,研究渗碳处理高强轴承钢的微观组织、显微硬度、残余应力及滚动接触疲劳行为。结果表明:两种工艺渗碳处理获得的碳化物类型、尺寸、形状、含量以及残余应力梯度均十分相近;较长时间渗碳处理获得的残余奥氏体在尺寸和含量上均明显大于较短时间渗碳处理的情况,两种工艺渗碳处理高强轴承钢在滚动接触疲劳过程中都会在亚表面最大切应力位置附近形成亮蚀区(Light etched region, LER);疲劳裂纹萌生于亮蚀区内,并向表面扩展,最终形成深度与最大切应力到表面距离相近的剥落坑。渗碳处理时间较长的高强轴承钢具有较高的滚动接触疲劳寿命,这是因为其渗层中具有相对规模较大的残余奥氏体;残余奥氏体会使裂纹尖端钝化与闭合,进而延缓疲劳裂纹扩展,提升疲劳裂纹扩展寿命。
In recent years, surface carburizing technology has been widely used in the preparation process of bearing steel to get better rolling contact fatigue performance. In this work, the microstructure, microhardness, residual stress and rolling contact fatigue behaviors of high-strength stainless bearing steel treated by carburizing with two different process durations were studied. The results show that, the type, size, shape and content of carbides and the residual stress gradient obtained by the two carburizing treatments are very similar. The size and content of residual austenite obtained by the carburizing treatment for a longer time is significantly larger than those obtained by the carburizing treatment for a shorter time. The high-strength bearing steel treated with carburizing by the two processes would form a light etched region(LER) near the position of the maximum shear stress on the subsurface during the rolling contact fatigue process. The fatigue cracks originate in the light etched region, and then expand to the surface, finally form a spalling pit with a depth similar to the distance from the maximum shear stress to the surface. The high-strength bearing steel with a longer carburizing treatment time has a higher rolling contact fatigue life because of the relatively large residual austenite in the carburizing layer. The residual austenite can passivate and close the crack tip, thereby delaying the fatigue crack propagation and improving the fatigue crack propagation life.
作者
杨红兵
邵子恒
颜莹
谷金波
迟宏宵
王斌
张鹏
张哲峰
YANG Hongbing;SHAO Ziheng;YAN Ying;GU Jinbo;CHI Hongxiao;WANG Bin;ZHANG Peng;ZHANG Zhefeng(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China)
出处
《材料导报》
北大核心
2025年第12期170-178,共9页
Materials Reports
基金
国家科技重大专项(J2019-Ⅵ-0019-0134)。
关键词
高强轴承钢
渗碳处理
残余奥氏体
滚动接触疲劳寿命
high-strength bearing steel
carburizing
residual austenite
rolling contact fatigue life
