Effects of Coiling Temperature after Hot Rolling on Microstructure, Texture, and Magnetic Properties of Non-Oriented Electrical Steel in Strip Casting Processing Route

Abstract

Low silicon non-oriented electrical steel is produced using a novel strip casting processing route. The focus is on investigating the effects of coiling temperature after hot rolling on microstructure, texture evolution, and magnetic properties. A fine microstructure with weak λ-fiber texture is formed after coiling at 650 °C. By contrast, a much coarser microstructure with a much stronger λ-fiber texture is produced after coiling at 750 °C. After cold rolling and annealing, a fine and inhomogeneous recrystallization microstructure dominated by mild λ-fiber, α-fiber, and γ-fiber recrystallization texture is formed in the case of coiling at 650 °C. By contrast, a coarse and inhomogeneous recrystallization microstructure characterized by strong Goss, α-fiber, and weak λ-fiber together with extremely weak γ-fiber recrystallization texture is formed in the case of coiling at 750 °C. Much lower iron loss and higher magnetic induction are obtained in the latter case as a result of the more desirable recrystallization microstructure and texture. It underscores that the relatively higher temperature of coiling has a similar effect as the conventional hot-band normalizing. Hence, the hot-band normalizing might be omitted in the fabrication of high-performance non-oriented electrical steels using this novel and compact strip casting production route.