EFFECT OF NORMALIZING ON TEXTURES OF THIN GAUGE GRAIN-ORIENTED SILICON STEEL

The main purpose of normalizing for traditional high temperature Hi-B silicon steel is to obtain enough inhibitors and ensure abnormal growth of Goss grains during final annealing treatment. While compared with high temperature Hi-B silicon steel, inhibitors in thin-gauge grain oriented silicon steel, which is prepared by low temperature method, are obtained mainly by nitriding other than by normalizing. In this work, two kinds of thin-gauge grain-oriented silicon steel specimens with and without normalizing were prepared. Effects of normalizing on microstructures and textures of thin- gauge grain-oriented silicon steels were investigated by EBSD and XRD techniques. The results showed that there were significant differences in the primary recrystallization textures between the specimens processed with or without normalizing, which were named as normalizing specimens and non-normalizing specimens respectively, and so did secondary recrystallization textures. It could be found that compared with the non -normalizing specimens, the intensities of {411} <148> and {111} <112> primary recrystallization textures are lower in normalizing specimens, while the intensity of Goss texture is higher. The secondary re crystallization texture of normalizing specimens, which had excellent magnetic properties, were characterized as sharp Goss texture, while Brass texture and deviated Goss texture secondary recrystallization textures were obtained in the non -normalizing specimens. Besides, higher proportion of 20-45 high-angle boundary surrounding Goss grains were shown in the normalizing specimens. However, the average grain size of normalizing and non normalizing specimens were almost identical (20 mu m), and their grain size distribution was similar. For the thin gauge grain-oriented silicon steel prepared by low temperature method, normalizing exerted crucial effects on magnetic properties by increasing the proportion of Goss oriented "seeds" prior to cold rolling and providing appropriate environment for Goss recrystallied grains.