ORIENTATION GRADIENTS IN α-FIBRE GRAINS OF COLD ROLLED IF STEELS

The plastic behavior of the < 110 >//RD orientations, and specially that of the {001}< 110 > orientation, under severe cold reductions is addressed. Based on the orientation dependence of the stored energy, the {001}< 110 > orientation is known to lack from structured misorientation gradients and significant dislocation storage after plastic deformation which makes the former orientation not particularly prone to enhancing the recrystallization process. Recent evidences, however, indicate that {001}< 110 > orientation plays a relevant role in the origin of {h11}< 1/h,1,2 > orientations (predominantly {311}< 136 > and {411}< 148 > orientations) observed in the recrystallization texture of severely deformed IF steels. The complete understanding of the development of the recrystallized {h11}< 1/h,1,2 > orientations in IF steels is, therefore, of relevance as it deteriorates the optimum gamma-fibre texture required for deep-drawability applications. The plastic instability of {001}< 110 > grains in a cross-rolled IF steel is evaluated in the present work. The extensive characterization of the deformed substructure along with partially recrystallized data confirmed the oriented nucleation origin of {h11}< 1/h,1,2 > orientations from deformed {001}< 110 > grains. Innovative crystal plasticity calculations accounting for the position of the grain boundary plane suggested that the recrystallized {h11}orientations could result from a low Taylor value nucleation criterion.