Microstructure, Texture, and Formability of Nb+Ti Stabilized High Purity Ferritic Stainless Steel

Abstract

The microstructure, texture, and formability of Nb+Ti stabilized high purity ferritic stainless steel were investigated. The interstitial element carbon and nitrogen could be fully stabilized with niobium and titanium, and the precipitates were mainly composed of TiN and NbC. By analyzing the texture in various thermomechanical processes, the intensity of α-fiber obtained during hot rolling was reduced greatly after annealing and non-uniform γ-fiber was obtained. The favorable γ-fiber was observed in cold rolled and annealed sheet, whereas the maximum value of texture is located in (554)<225>. The formation of this shifted texture was mainly attributed to the influence of “Zener” drag and selective growth. Finally, the high purity steel showed an excellent formability, which was reflected in a marked increase in average plastic strain ratio (average of 1. 70) compared with the traditional steel sheet (average of 1.06).