A quantitative evaluation was made of the dislocation structures due to cyclic plasticity with small strain amplitudes in 316L austenitic stainless steel. Firstly, 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. The observations showed that cyclic loading with larger strain amplitudes resulted in the organization of more uniform dislocation cell structures. Secondly, an image analysis method for evaluation of the transmission electron microscopic images was proposed. The proposed method quantitatively evaluated the strain amplitude dependency of the organization of dislocation structures. Finally, the accumulation of shear slips on slip systems during cyclic loading was estimated by using crystal plasticity finite element analysis. The distribution of the accumulated shear slips correlated with the organization of dislocation structures.

Quantitative Evaluations for Strain Amplitude Dependent Organization of Dislocation Structures due to Cyclic Plasticity in Austenitic Stainless Steel 316L. T.Mayama, K.Sasaki, M.Kuroda: Acta Materialia, 2008, 56[12], 2735-43