With the development of the aviation industry, the operating conditions of aero-engine bearings have become increasingly severe. To improve the lifespan of bearings, a new type of high-temperature bearing steel BG801 has been produced. In this study, a ball-on-rod rolling contact fatigue (RCF) tester is used to examine the RCF damage evolution process and failure mechanism of BG801 bearing steel. The mechanical properties and organizational structure of BG801 bearing steel are characterized at the millimeter, micrometer, and nanometer scales. The damage evolution during the test is explored and the failure mechanism is analyzed. The research results show that the uniformly distributed refined M7C3 carbides and matric grains refinement produced in the subsurface layer during the carburizing process are the main factors that improve the anti-RCF performance of BG801 bearing steel. The RCF of BG801 bearing steel is caused by the interaction of the non-uniform distribution of subsurface M7C3 carbides, the existence of the second phase inside the M7C3 carbides, and the degradation of the mechanical properties of the matrix. This study provides an in-depth analysis of the RCF failure mechanism of BG801 bearing steel for the first time. The results provide data for the material’s performance optimization and engineering applications.

中文翻译：

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基于BG801高温轴承钢多尺度分析的滚动接触疲劳失效机制


随着航空工业的发展，航空发动机轴承的运行条件越来越严峻。为了提高轴承的使用寿命，生产了一种新型高温轴承钢 BG801。本研究采用球杆滚动接触疲劳 （RCF） 测试仪研究了 BG801 轴承钢的 RCF 损伤演变过程和失效机理。BG801 轴承钢的机械性能和组织结构在毫米、微米和纳米尺度上进行了表征。探讨了测试过程中的损伤演变并分析了失效机理。研究结果表明，渗碳过程中在地下层中产生的均匀分布的细化M7C3碳化物和基质晶粒细化是提高BG801轴承钢抗RCF性能的主要因素。BG801 轴承钢的 RCF 是由 M7C3 碳化物亚表面分布不均匀、M7C3 碳化物内部第二相的存在以及基体力学性能退化的相互作用引起的。本研究首次深入分析了BG801轴承钢的RCF失效机理。结果为材料的性能优化和工程应用提供了数据。