Role of Nb-bearing inhibitors in grain-oriented silicon steel manufactured by low-temperature slab reheating process

Abstract

A comparative study of precipitates, microstructure, texture and magnetic properties between conventional and Nb-bearing grain oriented silicon steel was carried out. The results show that fine and dispersed Nb-bearing particles are formed in Nb-bearing steel and show stronger pinning force during the whole heat treatment process, which makes a significant effect on the microstructure and texture evolution during the preparation process. Compared to conventional grain oriented silicon steel, Nb-bearing steel exhibits finer microstructure and possesses more Goss grains in hot-rolled band and normalized band. In primary recrystallized band, fine and uniform microstructure is presented in Nb-bearing steel, meanwhile, it is also characterized by strong γfiber and {114}<481> texture. After final annealing, Nb-bearing steel shows better magnetic properties, B 800 =1.87 T and P 1.7/50 =1.25 W kg -1 . In summary, niobium can be used as an effective inhibitor formation element to produce high quality Nb-bearing grain oriented silicon steel manufactured by low-temperature slab reheating process.