Influences of Heterogeneous Nano-Structure Developed in Heavily Cold-Rolled Austenitic Stainless Steel on Texture and Ductility

SUS316LN austenitic stainless steel was simply and heavily cold-rolled up to 92% reduction in thickness. The microstructure developed was composed of complicated heterogeneous nano-structure; "eye-shaped" twin domains, which were surrounded by shear bands, were embedded in low-angle lamellar boundaries. The cold-rolled austenitic steel exhibited marvelous high strength of 1.95 GPa when tensile tested normal to the rolling direction, while lower strength of 1.57 GPa along the rolling direction. Moderate ductility around 10 % was still retained in spite of the high strength. The superior mechanical properties of the heavily cold-rolled austenitic stainless steel would be attributed to complicated heterogeneous nano-structures. These achieved strengths were comparable with those obtained by methods of severe plastic deformation.