常化处理对薄规格取向硅钢织构的影响

EFFECT OF NORMALIZING ON TEXTURES OF THINGAUGE GRAIN-ORIENTED SILICON STEEL

利用EBSD和XRD技术对比分析了常化和不常化2种工艺对薄规格取向硅钢组织及织构的影响.结果表明,2种工艺条件下的初次再结晶和二次再结晶织构存在着明显的差异.经过常化处理的样品初次再结晶组织中{411}<148>和{111}<112>织构组分比不常化样品的低,但Goss织构组分比不常化样品的高;常化处理的样品二次再结晶织构多为锋锐的Goss织构,磁性能优异,而不常化处理的样品二次再结晶织构多为Brass织构和偏Goss织构.此外,经过常化处理样品的初次再结晶组织中Goss取向晶粒周围分布的20°~45°大角度晶界所占比例高于不常化处理样品.2种样品初次再结晶后的平均晶粒尺寸差别并不明显,均为20μm,而且整体晶粒尺寸分布也相近.常化处理对最终磁性能有决定性影响,主要体现在提高冷轧前Goss取向"种子"的比例以及优化再结晶组织中Goss取向晶粒周围的织构环境.

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 normaliz- ing 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 com- pared with the non- normalizing specimens, the intensities of {411 } 〈 148〉 and { 111 } 〈 112〉 primary recrystalliza- tion 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 ob- tained 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 ~tm）, 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 mag- netic properties by increasing the proportion of Goss oriented ＂seeds＂ prior to cold rolling and providing appropri- ate environment for Goss recrystallied grains.