轴承钢服役中白蚀形成动力学建模

马氏体基轴承钢在服役过程中因周期性载荷作用会发生滚动接触疲劳。虽然滚动体/滚道接触表面剥落或点蚀可通过合理润滑得以改善，但次表层发生的微观组织退化由于赫兹接触应力作用于次表面的剪切应力分布的典型特性难以避免。这种作用于次表层的剪切应力会诱使三种类型的组织退化依次发生：即，白蚀区、灰蚀区、白蚀带。其中，白蚀区是在滚动接触疲劳早期出现的一种显微组织转变现象，通常在千分之一基本额定寿命时就会发生，常发生在非金属夹杂（氧化铝、一次碳化物）附近，呈对出现，且与滚动方向呈45°方向。基于此考虑，拟从“应力诱导碳扩散”动力学的角度对“白蚀”的形成进行建模和计算。

Martensitic-based bearing steels undergo rolling contact fatigue (RCF) under cyclic loading during service. Although spalling or pitting on the contact surfaces between rolling elements and raceways can be mitigated via proper lubrication, microstructural degradation occurring in the subsurface is unavoidable due to the typical characteristics of the shear stress distribution of Hertzian contact stress acting on the subsurface. This shear stress acting on the subsurface can induce three types of microstructural degradation to occur sequentially: white etching area (WEA), gray etching area (GEA), and white etching band (WEB). Specifically, WEA is a microstructural transformation phenomenon that emerges during the early stage of RCF, typically occurring when the service life reaches one-thousandth of the basic rated life. It frequently forms near nonmetallic inclusions (e.g., alumina, primary carbides), appears in pairs, and is oriented at 45° to the rolling direction. In view of the above, this study intends to conduct modeling and calculations on the formation of "white etching" from the perspective of stress-induced carbon diffusion kinetics.