【作者】 张世峰；

【导师】 左良； 沙玉辉；

【作者基本信息】 东北大学 ， 材料学， 2009， 硕士

【摘要】 双辊薄带连铸生产硅钢具有独特优势,受到世界钢铁行业的关注。热轧和常化是在硅钢生产中具有重大影响的前端工序,决定了硅钢制造全流程的织构与组织特征及演变规律,最终影响磁性能。因此,开展双辊薄带连铸硅钢热轧和常化过程中组织及织构研究,对双辊薄带连铸应用于硅钢生产具有重要意义。本研究采用双辊薄带连铸技术铸轧制得2mm厚薄带坯,热轧到1mm并进行900℃、1000℃和1100℃常化处理。通过对铸态、热轧和常化态样品进行组织和织构分析,探讨了织构形成与演变。本研究获得如下主要结果：(1)双辊薄带连铸硅钢铸坯由晶粒大小不均匀的单相铁素体构成：表层为等轴晶,表层和中心层之间为不发达的柱状晶,中心层为等轴晶。铸轧薄带织构在厚度方向存在梯度：表层以{100}织构为主；过渡层以偏离{100}方向的铸轧织构{115}为主,同时存在{110}剪切织构；中心层以典型的结晶织构{110}<110>为主。(2)热轧改变了双辊薄带连铸硅钢的织构分布。热轧薄带亚表层和过渡层以Goss织构为主,同时存在较强的(113)[332]织构；亚表层到中心层织构变化显著,中心层主要为平面应变织构α和γ织构,Goss织构消失。(3)温度为700℃,热轧压下量50%时,薄带连铸硅钢热轧坯在900℃和1100℃之间增加常化时间,均无法完全再结晶得到尺寸均匀的组织。(4)硅钢连铸薄带的常化织构与热轧薄带织构近似,亚层和过渡层以Goss织构为主,同时存在较强的(113)[332]织构；过渡中心层织构变化显著,中心层主要为平面应变织构α和γ织构,Goss织构消失。随常化时间的增加和常化温度的提高,亚层Goss织构强度减弱，但Goss织构仍为主要织构。(5)在1200℃下60%压下率热轧,3.67%Si钢常化再结晶动力学方程为：Xrex=1-exp[-0.693(t/t0.5]0.7],再结晶激活能为288kJ/mol。更多还原

【Abstract】 The production of silicon steel by strip casting has a unique advantage, which has brought a worldwide interest in the iron and steel industry. Hot rolling and normalizing are vital front procedures in the manufacturing of silicon steel, which affect the microstructure and texture development and influence the final magnetic property. So the study on micostructures and textures during hot rolling and normalizing are important and necessary.In this study,2 mm thick silicon steel strip was produced by strip casting, afterwards hot rolled into 1 mm and then normalized at three temperatures for various time. The microstructure and texture of cast, hot rolled and normalized strips were investigated. Recrystallization of 3.67% Si steel were studied with point counting.The obtained results show that the microstructure of cast strip is heterogeneous through thickness:equiaxed grains in the surface, poor developed columnar grains from the surface to the centre layer. A through thickness gradient of texture forms in cast stript:{001} in surface layer,{115} and{110} betweeen surface layer and centre layer,{110}<110> in the centre layer.The hot rolled textures of the surface and the 1/4 layer are mainly made up of Goss component, and mainly a and y fibers in the centre layer.The hot rolled strip with reduction rate of 50% at 700℃, can not get fully recrystallized and by normalizing at 900,1000 and 1100℃.After normalizing, the silicon steel strip remains the texture component of hot rolled strips in various layers. However, Goss texture in the surface layer decreases a little with the increase of normalizing temperature or time.When 3.67Si% steel hot rolled with reduction rate of 60% at 1200℃, the recrystallization curvs is Xrex=1-exp(?)and the recrystallization activation energy is 288kJ/mol.更多还原