Quantitative evaluations for strain amplitude dependent organization of dislocation structures due to cyclic plasticity in austenitic stainless steel 316L
- 作者：Tsuyoshi Mayama ; Katsuhiko Sasaki ; Mitsutoshi Kuroda
- 关键词：Image analysis ; Low cycle fatigue ; Transmission electron microscopy (TEM) ; Dislocation structure ; Finite element analysis (FEA)
- 刊名：Acta Materialia
- 出版年：2008
- 期刊代码：1_13596454
- 类别：ms
- 出版时间：July 2008
- 卷：56
- 期：12
- 页码：2735-2743
- 文件大小：1124 K
摘要
This study is a quantitative evaluation of dislocation structures due to cyclic plasticity with small strain amplitudes in austenitic stainless steel 316L. First, dislocation structures in specimens after 100 cycles of cyclic loading with strain amplitudes of 0.25%, 0.75%and 1.0%were observed by transmission electron microscopy (TEM). The observations showed that cyclic loading with larger strain amplitudes results in the organization of more uniform dislocation cell structures. Secondly, an image analysis method for evaluation of the TEM images is proposed. The proposed method quantitatively evaluates the strain amplitude dependency of the organization of dislocation structures. Finally, the accumulation of shear slips on slip systems during cyclic loading is estimated by using crystal plasticity finite element analysis. The distribution of the accumulated shear slips correlates with the organization of dislocation structures.