【作者】 冯莉莉；

【导师】 沙玉辉；

【作者基本信息】 东北大学 ， 材料学， 2008， 硕士

【摘要】 硅钢主要用作各种电机和变压器的铁芯,是电力、电子和军事工业中不可缺少的软磁合金。再结晶织构是决定取向硅钢磁性能的关键因素之一。因此,探索有效调控取向硅钢织构的新方法,可为进一步改善磁性能拓展更大的空间。本文将异步轧制引入取向硅钢薄板的制备过程,采用不同速比(1.0、1.125、1.19)将工业热轧板轧至0.30mm厚。利用X-射线衍射技术与背散射电子衍射技术,研究冷变形和初次再结晶过程中的宏微观织构特征及形成规律。同步轧制及异步轧制方式下,取向硅钢薄板的冷轧织构主要由α和γ纤维织构组成,峰值分别出现在{001}<110>和{111}<110>。异步轧制对冷轧织构强度的影响依赖于层厚和速比：降低快辊侧各厚度层及中间层的织构强度,提高慢辊侧的织构强度；总体上降低冷轧织构强度,影响程度随速比增加而增大。剪切带与轧面大约成±20°和±35°,形成剪切带的晶粒的面积分数随速比增大而提高。初次再结晶过程中,各种工艺冷轧薄板的织构主要由α、η、γ以及{100}组分组成。异步轧制方式未显著改变织构的演变特征：α、{100}面织构强度随温度升高而降低；η织构随温度升高逐渐强化；{111}<112>和{111}<110>组分分别随温度升高呈增强和减弱趋势,γ织构取向密度峰随之移至{111}<112>；随着冷轧γ织构强度和剪切带密度的提高,γ和η织构强度增大。但与同步轧制方式相比,异步轧制提高η和γ组分强度,促进{111}<112>成为γ织构强点。在再结晶初期,γ取向的再结晶晶核优先在γ取向形变带内形核,也易于在α和γ取向的形变带之间的界面上形核。更多还原

【Abstract】 Grain-oriented silicon steel sheets are indispensable soft magnetic materials in electric, electronic and military industries, as commonly used in hydroelectric power plant generators and electric motors. The magnetic properties of grain-oriented silicon steels are closely related to recrystallization texture. Thus, the exploration of a new method for more effective texture control can provide a new approach to optimize the magnetic properties of grain-oriented silicon steels.In present thesis, asymmetric rolling was introduced into cold rolling process of grain-oriented silicon steel sheets. The 0.3mm thick cold rolled sheets were prepared with speed ratios of 1,1.125 and 1.19 asymmetric rolling in all passes. Afterwards, vacuum annealing was carried out at 600,620,640,835℃for 5 minites. The textures after cold rolling and during primary recrystallization process were investigated by Electron Back Scattered Diffraction (EBSD) and X-Ray diffraction (XRD) methods.Deformation textures produced by symmetric and asymmetric rolling are both composed of a and y fibers, with the intensity peaks at{001}<110> and{111}<110>, respectively. Asymmetric rolling decreases the intensities of deformation textures in the middle and fast roller side layers, but increases in the slow roller side layers. Asymmetric rolling generally weakens the deformation textures, and this effect is more obvious with the increasing speed ratio. Shear bands are inclined to the rolling plane at approximate angles of±20°and±35°, the area fraction of the grains with shear bands increases with speed ratio.The textures of early stage primary recrystallization in the sheets by different rolling methods consist ofα,η,γand{100} fibers. Asymmetric rolling does not remarkably change the development characteristics of textures as primary recrystallization proceeds:a and{100} fibers are continuously weakened whileηfiber is strengthened; {111}<112> component is increased but the{111}<110> component are decreased, leading to the intensity peak of y fiber towards{111}<112>; as the intensity of cold rolled y fiber and density of shear band increase, the intensities of y andηfibers are strengthened. Compared with symmetric rolling, asymmetric rolling can strengthenηand y fibers, and promote the{111}<112> to be the peak of y fiber. At the early stage of recrystallization, the nuclei of y orientation preferentially form within the deformed y bands as well as the boundaries between deformed a andγbands.更多还原