Evaluation of Intermediate Annealing on Nb-Stabilized Ferritic Stainless Steel

This study seeks to evaluate the effect of intermediate annealing on the microstructure, texture, and formability of Nb-stabilized ferritic stainless steel. Two routes - direct cold rolling and cold rolling with an intermediate annealing were performed. The total reduction was 80%, 3-0.6 mm and 3-1.2-0.6 mm. The characterization of the samples was conducted using X-ray diffraction, electron backscatter diffraction, and tensile tests to evaluate the formability by the average normal anisotropy coefficient, (r) over bar value. The results showed that intermediate annealing promoted the strongest gamma-fiber with peak at {111}< 112 > and weak alpha-fiber after cold rolling. After the final annealing, it was observed that intermediate annealing reduces the banded microstructure and gamma-fiber, and improves the gamma-fiber uniformity and the (r) over bar value. It is worth noting that the gamma-fiber fraction was the same for direct reduction. The increase in (r) over bar value was related to the reduction in theta-fiber and the uniformity of texture recrystallization.