Strain Distribution Analysis of Two Perpendicular Planes in SUS310S Austenitic Stainless Steel Using Digital Image Correlation

Abstract

We performed a strain distribution analysis of two perpendicular planes in SUS310S austenitic stainless steel using digital image correlation (DIC). Strain bands in both the rolling direction, (RD)-transverse direction and RD-normal direction planes, were connected at an edge, and the formation of a strain plane surrounded by the strain bands in each plane was confirmed. Furthermore, we found that the three-dimensional strain distribution can be inferred by analyzing the strain distribution of two perpendicular planes using DIC. The finite element method (FEM) was used to verify the formation of macro and micro strain bands. The FEM analysis also revealed that the connection of micro strain bands led to the formation of macro strain bands. The angle of macro strain bands to tensile loading direction was dependent on preferential deformation site distribution. In contrast, the angle of micro strain bands was mainly determined by preferential deformation site distribution when the angle of preferential deformation site to tensile loading direction was <50° and by maximum shear stress when it was >50°. From these results, we concluded that (i) the angle of the macro strain bands observed by DIC to tensile loading direction was mainly determined by the preferential deformation site distribution; and (ii) the angle of the micro strain bands was determined by both the preferential deformation site distribution and maximum shear stress.