Effect of the size and dispersion of precipitates formed in hot rolling on recrystallization texture in ferritic stainless steels

Abstract

In the present paper, the size and dispersion of precipitates in ferritic stainless steels have been varied by applying different hot rolling processes, the effect of which on the evolution of recrystallization textures was investigated. The precipitate characterization was observed and studied by transmission electron microscopy and the texture evolution processes were characterized by X-ray diffraction and electron backscattering diffraction. The results show that low temperature finish rolling can promote the formation of a large number of fine and dense TiC precipitates in hot band. These fine and dense precipitates can be inherited in the final sheet, and are beneficial to facilitating the nucleation of randomly oriented grains by promoting the formation of inhomogeneous cold rolled microstructure, strongly suppressing the growth of recrystallized grains by pinning grain boundary migration, thereby weakening the formation of γ-fiber recrystallization texture and deteriorating the formability of final sheet. By contrast, strong γ-fiber recrystallization texture is developed in the sample with sparsely distributed coarse precipitates. Therefore, the size and dispersion of precipitates formed in hot rolling have significant effects on the nucleation of randomly oriented grains and the growth of recrystallized grains during recrystallization annealing, which play important roles in controlling the γ-fiber recrystallization texture in ferritic stainless steels.