The initial grain size effect on the tensile-deformed microstructure in Type 310S austenitic stainless steel

Abstract

We investigated the initial grain size effect on the tensile-deformed microstructure in Type 310S austenitic stainless steel. Specimens A and B were prepared with different initial grain sizes (25 and 67 μm). With increasing strain in both specimens, dislocation density increased and the crystallite size decreased. Moreover, the dislocation density difference of specimens A and B gradually increased with increasing strain. Kernel average misorientation (KAM) values at the grain boundaries were high and increased with increasing strain in both specimens. Additionally, the KAM value of specimen B was lower than that of specimen A. This is because the grain boundary area in specimen B was lower than that in specimen A. On the other hand, characteristics of dislocation cell structures, such as the dislocation cell size and the misorientation between dislocation cells, were almost the same in both specimens. From these results, we concluded that the dislocation density difference of strained specimens A and B is attributed to the difference in the dislocation cell structure amount formed in specimens A and B.