TEXTURE OF Nb-CONTAINING FERRITIC STAINLESS STEEL AFTER SECONDARY RECRYSTALLIZATION

We present the results of the texture evolution of two Nb-containing ferritic stainless steels (FSS) annealed at 1523K for 2 h to promote secondary recrystallization (SR). The steel sheets (4-mm thick) with 16 wt-% Cr and distinct Nb contents (0.37 and 0.56 wt-%) were obtained by hot rolling. The crystallographic textures were determined by conventional X-ray diffraction (XRD). Microstructural characterization was performed in hot-rolled and annealed samples using scanning electron microscopy (SEM) and electron backscattering diffraction (EBSD). The precipitates in Nb-containing FSS were electrolytically extracted from the ferritic matrix and analyzed by SEM and XRD. The results show that hot-rolled sheets display partial recrystallization. Most Goss grains from primary recrystallization are found close to the surface. Recovered grains (pancake morphology) displaying pronounced (001)< 011 > and alpha-fiber texture components are found predominantly at the center layer. After SR-annealing grains displaying abnormal growth are seen in the two types of steel. The texture of the annealed sheets was also evaluated with respect to the composition changes and through-thickness effects. The results were compared to others FSS and bcc materials such as low-carbon and silicon steels.