机加工表面残余应力及其疲劳寿命评价的研究进展

随着航空、航天、核电、海洋装备、汽车制造行业的蓬勃发展,特别是国家空天深海战略的实施,高腐蚀、高交变载荷等复杂服役环境对零件的可靠性和使用寿命的要求日趋严格。机械加工表面完整性作为零件性能指标的评价标准,得到越来越多的重视。残余应力作为表面完整性的重要参数之一,与零件疲劳寿命和使用性能密切相关,因此有必要对机械加工过程中残余应力的生成机理进行研究。主要介绍了机械加工表面残余应力的定义及其对材料性能的影响,对中子衍射法和X射线衍射法检测残余应力的优缺点进行了比较,从实验方法、解析方法以及有限元方法 3个方面对机械加工过程中残余应力的生成机理进行了总结,分析了切削参数、刀具几何、材料性质对残余应力生成的影响,总结了残余应力与疲劳寿命之间的作用关系。最后,探讨了机械加工表面残余应力生成机理以及疲劳寿命评价研究过程中存在的问题。

Research Progress on Evaluation of Surface Residual Stress and Fatigue Life of Machined Products

With the rapid development of aerospace engineering, nuclear power industry, marine engineering equipment and motor industry, especially the implementation of the national aerospace and marine strategy, the requirements are stricter on the reliability and service life of components in the complex service environment such as high corrosion and high alternating load. As an important evaluation criterion of component performance, surface integrity in machining has drawn more and more attention. Surface residual stress, as a major parameter of surface integrity, is closely related to fatigue life and functional performance of manufactured components. Therefore, it is necessary to investigate the formation mechanism of surface residual stress in machining. This paper introduced the definition of residual stress and its effects on material performance, compared the advantages and disadvantages of the neutron diffraction method and the X-ray diffraction method for residual stress determination, summarized the formation mechanism of surface residual stress in machining by experimental, predictive and FEM methods, analyzed effects of cutting parameters, tool geometry and material property on surface residual stress. The interrelationship between residual stress and fatigue life was summarized. Finally, the problems were explored in the formation mechanism of surface residual stress in machining and fatigue life evaluation.