A novel ultra-low carbon grain oriented silicon steel produced by twin-roll strip casting

A novel ultra-low carbon grain oriented silicon steel was successfully produced by strip casting and two stage cold rolling method. The microstructure, texture and precipitate evolution under different first cold rolling reduction were investigated. It was shown that the as-cast strip was mainly composed of equiaxed grains and characterized by very weak Goss texture ({110} '001') and lambda-fiber ('001' //ND). The coarse sulfides of size similar to 100 nm were precipitated at grain boundaries during strip casting, while nitrides remained in solution in the as-cast strip and the fine AIN particles of size similar to 20-50 nm, which were used as grain growth inhibitors, were formed in intermediate annealed sheet after first cold rolling. In addition, the suitable Goss nuclei for secondary recrystallization were also formed during intermediate annealing, which is totally different from the conventional process that the Goss nuclei originated in the subsurface layer of the hot rolled sheet. Furthermore, the number of AIN inhibitors and the intensity of desirable Goss texture increased with increasing first cold rolling reduction. After secondary re crystallization annealing, very large grains of size similar to 10-40 mm were formed and the final magnetic induction, B-8, was as high as 1.9 T. (C) 2016 Elsevier B.V. All rights reserved.