Correlation between formability, ridging and recrystallization texture development in ferritic stainless steel fabricated by introducing intermediate annealing during cold rolling

Abstract

Introducing intermediate annealing (IA) during cold rolling is a most promising approach for reinforcing ridging resistance and r-value of ferritic stainless steels, but it usually deteriorates anisotropy of r-value. To solve this problem, the texture evolution, especially recrystallization texture formation at various IA temperatures and its effect on formability and ridging was investigated. During cold rolling, the crystallite appeared along shear band because of the sequential starting of multislip systems, and due to high rotation tendency of shear component {110}〈001〉 towards stable {111}〈112〉 it owned sharp {111}<112 > and {110}<001 > components, and then during annealing, it preferentially induced recrystallized nuclei, and the γ-fiber recrystallization texture having peak intensity near {111}<112 > was formed owing to high grow tendency of preferentially formed {111}<112 > recrystallized grain. Moreover, IA at 850 °C promoted the rotation of crystallites towards stable {111}<112 > during cold rolling before final annealing compared with IA at 950 °C and above, while for IA at 950 °C and above, higher IA temperature was conducive to nucleating randomly oriented grain, and adverse to consuming other deformed grain by {111}<112 > recrystallized grains during final annealing. Therefore, the γ-fiber recrystallization texture in the final sheet gradually weakened and {110}<001 > component first strengthened and then weakened with increasing IA temperature. In addition, the banded grain clusters having similar r-value or those having same orientation and its variants with same sign of ε23 were less distinct and their size was finer in the final sheet after IA at 950 °C than those after other IA temperatures by reason of the occurrence of partial recrystallization at lower temperature and significant grain growth at higher temperature during IA. With increasing IA temperature, average r-value increasingly reduced, while anisotropy of r-value and ridging resistance first heightened and then lowered, which were lower at 850 °C and the optimal matching was realized at IA temperature of 850 °C.