Unraveling surface microtexture evolution mechanism of austenitic stainless steel thin strip during asymmetric rolling by crystal plasticity modeling

The numerical simulation and experimental investigation on the surface microtexture evolution of austenitic stainless steel (ASS) thin strip during asymmetric rolling (ASR) process are involved. The crystal plasticity finite element method was employed to evaluate the deformation behavior of ASS thin strip during ASR, and also, the deformation behavior of ASS thin strip during symmetric rolling was comparatively studied, with a purpose of unraveling the surface microtexture evolution mechanism during ASR. Both numerical and experimental results demonstrate an increase in the surface roughness of strip surface in contacting with the roll of fast side, along with the increase in the differential speed ratio during ASR. A comprehensive analysis on ASR mechanism is performed, revealing that the equivalent strain rate increases in conjunction with the increase in the differential speed ratio, resulting in uneven plastic deformation of grains and the formation of undulated surface microtexture, which ultimately compromise the surface quality. In addition, ASR introduces remarkable shear force on the workpiece, thereby promoting the formation of 112 and 111 oriented grains. The effects of 112 and 111 components on the slip and deformation behavior are discussed, and the results show that 112 orientation is detrimental to the surface roughness of ASS thin strip during ASR, whereas 111 orientation exerts a negligible influence on the surface roughness of ASS thin strip during ASR.