Effect of intermediate annealing on texture, formability and ridging of 17%Cr ferritic stainless steel sheet

In order to improve the formability of ferritic stainless steel (FSS) sheets, the crystallographic texture of the sheets was modified by way of an intermediate annealing (IA) during the cold rolling. In the as-received hot band pronounced through-thickness texture gradients with a strong rotated cube orientation in the sheet center layer were observed. This strong initial texture has an impact on the texture and the resulting properties, including the undesired appearance of ridging, in the final recrystallized sheet. Instead of forming the {111}//ND γ-fiber texture typical of recrystallized low-carbon steel sheets, the recrystallization texture was notably shifted towards {334}〈48̄3〉. Introduction of an intermediate anneal during the cold rolling led to a weaker, more typical bcc rolling texture with less pronounced texture gradients. Accordingly, recrystallization gave rise to the characteristic γ-fiber texture. The evolution of the different rolling textures is interpreted by means of texture simulations based on the Taylor deformation theory. The recrystallization textures are explained in terms of a preferred nucleation of recrystallization at the preexisting grain boundaries and a subsequent growth selection. The improvement in sheet formability through the IA is demonstrated by means of analysis of the R-values. Ridging is assessed through surface profile measurements.