Effects of local microstructure on crack initiation in super martensitic stainless steel under very-high-cycle fatigue
Effects of local microstructure on crack initiation in super martensitic stainless steel under very-high-cycle fatigue
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DOI：
10.1016/j.ijfatigue.2022.107019
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发表时间：
2022-10-01
影响因子：
6
通讯作者：
Wang, Qingyuan
中科院分区：
文献类型：
--
作者：
Li, Xue;Dai, Yajun;Wang, Qingyuan
超级马氏体不锈钢以其优异的力学性能被广泛应用于承受循环载荷的结构构件中。研究了超高周疲劳（VHCF）条件下局部显微组织对超级马氏体不锈钢裂纹萌生行为的影响。结果表明，非夹杂物诱导裂纹萌生是VHCF失效的主要形式。由于II型裂纹过程，疲劳裂纹从马氏体板条的边界开始，导致形成位于细颗粒区（FGA）核心的滑动区。马氏体板条的大小和取向决定了滑移区的形态，但对断裂面FGA的形成影响有限。这些结果可有效提高超级马氏体不锈钢的使用安全性和可靠性。
Super martensitic stainless steel is known for its outstanding mechanical properties, which lead to its widely application in structural component bearing cyclic loadings. This study investigates the effect of local microstructure on the crack initiation behavior of a super martensitic stainless steel in the very high cycle fatigue (VHCF) regime. Results show that the non-inclusion-induced crack initiation is the dominating pattern of VHCF failure. Fatigue cracks initiate from the boundaries of the martensite lath due to the mode II cracking process, resulting in the formation of a slip area located at the core of the fine granular area (FGA). The size and the orientation of the martensite lath determine the morphology of the slip area but exert limited influence on the formation of the FGA at the fracture surface. These results may effectively improve the service safety and reliability of super martensitic stainless steel.