材料期刊网

通过调整最终退火保护气氛来控制0.18 mm厚含Cu中温取向硅钢二次再结晶时抑制剂的熟化和分解行为, 从而达到提高二次再结晶后Goss织构锋锐度和磁性能的目的. 运用EBSD系统观察和分析二次再结晶中断抽出试样的组织和取向. 结果表明: 提高高温退火气氛中的N₂比例至90%, 最终0.18 mm规格成品磁感达1.95 T. 成品减薄后样品中抑制剂的粗化行为受气氛的影响更为强烈, 表现在提高N₂比例后初次晶粒尺寸减小, 二次再结晶持续时间延长, 此时Goss取向晶粒拥有足够的时间发生异常长大以获得尺寸优势, 从而抑制偏转Goss取向晶粒的异常长大, 提高了Goss织构的锋锐度和薄规格成品的最终磁性能.

The development trend of grain oriented silicon steel is reducing the slab reheating temperature and the thickness of final product. Medium temperature slab reheating grain oriented silicon steel bearing copper was characterized by omitting hot band annealing and larger range of secondary cold rolling reduction which was suitable for the preparation of thin gauge product. But less research were reported about thin gauge grain oriented silicon steel produced by medium temperature reheat technique. It was well known that the sharpness of secondary recrystallization Goss texture is deteriorated by the preparation of 0.18 mm thin gauge grain oriented silicon steel, poor secondary recrystallization and deviated Goss grains occurs by the influence of Goss seeds decreasing and inhibitor decrease. So the key point of producing thin gauge grain oriented silicon steel was controlling the precipitations ageing behavior. In order to improve the sharpness of Goss texture and the magnetic flux density after secondary recrystallization, secondary recrystallization behavior was controlled by annealing atmosphere in this work. The microstructure and texture of interrupted annealing specimens were measured by EBSD system. The results show that the magnetic flux density of 0.18 mm gauge specimen was 1.95 T after final annealing in 90%N₂ atmosphere. Due to the coarsening behavior of inhibitors was more strongly influenced by atmosphere in thin gauge silicon steel, the primary recrystallization grain size was smaller and secondary recrystallization duration was longer by improving volume fraction of N₂ during final annealing. In this condition, deviated Goss grains were inhibited while Goss grains have enough time for abnormal growth. As a result, sharp Goss texture and stable secondary recrystallization were guaranteed and high magnetic flux density of thin gauge final product was obtained.