升温速率对冷轧超薄取向硅钢再结晶行为的影响

Effect of Heating Rate on Recrystallization Behavior in Cold-rolled Ultra-thin Grain-oriented Silicon Steel

利用EBSD技术对比分析了升温速率对冷轧超薄取向硅钢再结晶行为的影响。结果表明,冷轧超薄带中再结晶形核位置、再结晶织构类型受升温速率的影响不大,主要取决于形变组织;剪切带、{111}〈112〉取向晶粒晶界、形变带和形变不均匀区均为再结晶的形核位置,剪切带的再结晶形核优势更为明显;再结晶晶粒取向以Goss({110}〈001〉)取向为主,同时存在{210}〈001〉、{310}〈001〉以及一定比例的杂乱取向。然而,升温速率显著影响Goss织构的强度及退火样品的组织均匀性;慢速升温条件下,Goss织构比例和锋锐度降低,说明回复导致不同织构的形变组织储存能差异减小,降低了Goss取向的形核优势;快速升温条件下,剪切带内的Goss晶核具有更大的形核优势,吞并临近的形变组织完成再结晶,形成更强和锋锐的Goss织构。此外,快速升温可提高再结晶完成后的组织均匀性、降低平均晶粒尺寸。

The effect of heating rate on the recrystallization behavior of ultra-thin oriented silicon steel was analyzed by using EBSD technique.The results show that the nucleation sites and the texture components of recrystallized grains were mainly determined by the deformed microstructure,not significantly affected by heating rate.The nucleation sites of recrystallized grains were observed in the deformed matrix,including the shear bands,grain boundaries between two{111}〈112〉grains,deformation bands and heterogeneous deformation zones.The preferential recrystallization nucleation is more obvious in the shear bands.Goss({110}〈001〉),{210}〈001〉and{310}〈001〉became the main texture in the annealed grain oriented silicon steel sheet,and a certain proportion of hybrid orientation were found.Heating rate was a direct factor which inf-luence the intensity of Goss and the microstructure uniformity.Enhanced recovery by low heating rate reduced the stored energy difference among texture components,which reduced the nucleation advantage of Goss orientation,thus the intensity and sharpness of Goss were weakened.The nucleation advantage of Goss was promoted during high heating rate,sharp Goss texture was strengthened after complete recrystallization.In addition,in case of rapid heating,the average grain size after recrystallization was reduced and the uniform distribution was improved.