Evaluation of Intermediate Annealing on Nb-Stabilized Ferritic Stainless Steel

posted on 05.12.2017 by Daniella Gomes Rodrigues, Cláudio Moreira Alcântara, Tarcísio Reis de Oliveira, Berenice Mendonça Gonzalez

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 value. The results showed that intermediate annealing promoted the strongest γ-fiber with peak at {111}〈112〉 and weak α-fiber after cold rolling. After the final annealing, it was observed that intermediate annealing reduces the banded microstructure and θ-fiber, and improves the γ-fiber uniformity and the r value. It is worth noting that the γ-fiber fraction was the same for direct reduction. The increase in r value was related to the reduction in θ-fiber and the uniformity of texture recrystallization.