Texture Development and Formability of Strip Cast 17% Cr Ferritic Stainless Steel

Abstract

In order to optimize the formability of ferritic stainless steel (FSS), control of the crystallographic texture is essential. In the present work, texture development of cast strips with different initial solidification structure during rolling and subsequent annealing and the formability of final sheets were investigated. Fully equi-axed and columnar grained cast strips of Fe17%Cr FSS were fabricated by a pilot twin-roll strip caster. The equi-axed and columnar grained bars cut from a conventional continuous cast slab were used as comparable specimens. It was shown that in the cold rolled and annealed sheet of fully equi-axed cast strip, uniform and strong γ-fiber recrystallization texture was formed and {001}‹110› component was almost eliminated. By contrast, the recrystallization texture in the conventional sheets with equi-axed and columnar initial solidification structures exhibited typical shift towards high-index {334}‹483›, which led to a reduced r-value as compared to that of the equi-axed cast strip. The final annealed sheet of fully columnar cast strip, however, showed weaker γ-fiber recrystallization texture and lower r-value than those of conventional sheets. It is, therefore, believed that twin-roll strip casting can improve the formability of 17% Cr FSS only under the pre-condition that appropriate solidification structure is obtained.