In situ observation for the fatigue crack growth mechanism of 316L stainless steel fabricated by laser engineered net shaping
In situ observation for the fatigue crack growth mechanism of 316L stainless steel fabricated by laser engineered net shaping
复制标题
激光净成形316L不锈钢疲劳裂纹扩展机理的原位观察
DOI：
10.1016/j.ijfatigue.2019.105272
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发表时间：
2020-01-01
影响因子：
6
通讯作者：
Song, Lijun
中科院分区：
文献类型：
--
作者：
Xu, Kang;Li, Bochuan;Song, Lijun
首次通过扫描电子显微镜（SEM）原位观察，对激光近净成形（LENS）工艺制备的316L不锈钢的抗疲劳裂纹扩展性能进行了研究。当疲劳裂纹靠近层带时，加载方向垂直于构建方向（BD）的疲劳裂纹扩展速率（FCGR）略低于加载方向平行于构建方向的情况以及传统316L的疲劳裂纹扩展速率。在非层带区域，三种情况下的疲劳裂纹扩展速率相当，且几乎不受拉长晶粒形态的影响。LENS工艺中的这种疲劳裂纹扩展速率特性与选区激光熔化（SLM）制备的316L不同，据信这一现象主要归因于该材料的织构特征和微观结构。
For the first time, the fatigue crack growth resistance of 316L stainless steel, fabricated by laser engineered net shaping (LENS) process, was investigated through in-situ SEM. The fatigue crack growth rate (FCGR), loading direction perpendicular to building direction (BD), was slightly slower than that of the parallel case and conventional 316L, when the fatigue crack approached the layer bands. In the area of non-layer band, the FCGRs for three cases were comparable, which was rarely affected by the elongated grain morphology. This FCGR characteristic in LENS process was different from the 316L manufactured by selective laser melting (SLM) and it was believed that this phenomenon is mainly attributed to the texture characteristic and microstructure in the presented material.