The effect of texture on ridging of ferritic stainless steel

Abstract

Ferritic stainless steel sheets exhibit ridging parallel to the rolling direction when subjected to tension or deep drawing. The origin of ridging behavior has not been clearly explained yet. Many people agree that ridging originates from different plastic anisotropies of grains. In this study, 430 and 409L stainless steels having columnar and equiaxed structures were chosen as initial specimens to elucidate the role of microstructure and composition on ridging. The specimens initially having the columnar structure showed severe ridging and 409L stainless steel showed an inferior surface quality. The existence of band-like colonies of similar orientations was found in the center of the sheets by electron back-scattered diffraction measurement. In addition, the previous models suggested by other researchers were examined quantitatively by the crystal plasticity finite element method. In order to obtain a more realistic ridging simulation, the specimens containing variously oriented colonies in a textured matrix were also considered. The simulated results showed that the lower plastic strain ratio of {001}〈110〉 colonies and different shear deformations of {111}〈110〉 or {112}〈110〉 colonies resulted in ridging.