【作者】 宁媛媛；

【导师】 沙玉辉；

【作者基本信息】 东北大学 ， 材料学， 2008， 硕士

【摘要】 硅钢是广泛应用于电力、电子、军工等领域的重要软磁材料。冷轧和退火是取向硅钢板材制造流程中组织结构发生重大变化的两个关键工序。探索可有效调控硅钢冷轧和再结晶织构的新方法,有利于建立自主知识产权的高品质硅钢先进制造技术。本文将异步轧制引入取向硅钢的制备过程,借助宏微观织构分析方法考察了轧制速比(1.0、1.125、1.19)对0.30mm厚取向硅钢薄板冷轧及再结晶织构的影响。研究结果表明：1、同步轧制和异步轧制方式下,取向硅钢薄板的冷轧织构均主要由以{001}<110>为强点的α织构及γ织构组成。异步轧制对快辊侧厚度层和中间层冷轧织构的影响幅度较大,降低α和γ中{111}<110>组分的强度,提高{111}<112>组分强度；对慢辊侧厚度层的影响幅度相对较小,倾向于提高α织构。整体而言,异步轧制倾向提高{111}<112>而降低{111}<110>强度,减弱α织构,该效应随速比增大而增强。2、不同轧制工艺下取向硅钢初次再结晶织构均由η{100}、{111}<112>及α等组分构成。随退火温度升高及时间延长,同步轧制薄板η强度略有降低,而异步轧制薄板η强度则有所提高；同步轧制薄板{111}<112>强度稍许提高,异步轧制薄板{111}<112>强度基本不变；同步和异步轧制薄板的{100}及α基本保持稳定。3、异步轧制影响主要再结晶织构组分的强度及其沿层厚的分布规律：(1)η织构组分—同步和异步轧制方式下,中间层强度均最低；异步轧制薄板慢辊侧高于快辊侧,而同步轧制薄板则是表层高于1／4层；异步轧制总体上提高η组分含量；异步轧制的作用主要体现在剪切应变对冷轧Y特别是{111}<112>组分的影响,其次剪切应变过大不利于η织构。(2){100}织构组分—异步轧制对{100}<011>组分的影响体现在其对冷轧{100}<011>组分的改变,对{100}<001>组分的影响与η组分相似；总体而言,1.125速比异步轧制倾向增加{100}。(3){111}<112>织构组分—异步轧制通过减少冷轧α和γ,使快辊侧及中间层的再结晶{111}<112>组分降低,进而总体上减小<111}<112>组分。(4)α织构组分—异步轧制使快辊侧及中间层再结晶α强度减弱、慢辊侧增强,总体上影响很小4、微观织构分析表明：异步轧制通过降低形核率减少再结晶{111}<112>组分；异步轧制通过同时提高形核率和长大速率(空间)强化再结晶η织构组分；{100}晶粒长大速率(空间)随速比增大而降低,但异步轧制稍许提高形核率,使1.125速比下的{100}组分较强；异步轧制由于降低长大速率(空间)而提高形核率,使其对再结晶α织构呈较弱的影响。更多还原

【Abstract】 Silicon steels are important soft magnetic materials widely used in electric, electronic and military industries. Annealing and cold-rolled processes are the two key processes during which the significant change of microstructure takes place. Searching for the new method to efficiently control cold rolling and recrystallization texture can promote to establish the advanced technologies with independent intellectual property rights for high quality silicon steel production.In this thesis, asymmetric rolling was introduced to investigate the effects of speed ratio on cold rolling and recrystallization texture of grain-oriented silicon steel sheets by macro-and microtexture analysis.The obtained results are as follows:1. The symmetric and asymmetric rolling textures are mainly made up ofαandγcomponents. Asymmetric rolling has a larger impact on center layer and fast roll side layers with decreased{111}<110> and increased{111}<112>, while it has a smaller impact on slow roll side layers with the enhancedα. As a whole, asymmetric rolling shows a more obvious tendency to increase{111}<112>, and reduce{111}<110> andαas the speed ratio is raised.2. Under different rolling process, the first recrystallization textures are all composed ofη, {100},{111}<112> andαcomponents. As the recrystallization proceeds, the intensity ofηdecreases slightly in the symmetrically rolled sheet while increases in the asymmetrically rolled sheet;{111}<112> is weakened and enhanced in the symmetrically and asymmetrically rolled sheet respectively;{100} andαcomponents remain almost constant both in the symmetrically and asymmetrically rolled sheets.3. Asymmetric rolling has some impacts on the intensity and the distribution through thickness of recrystallization texture components.(1)ηtexture component. The lowest intensity appears at center layer under both symmetric and asymmetric rolling; the intensity of the slow roll side is higher than that of the fast roll side in the asymmetrically rolled sheet, while the intensity of the surface is higher than that of the 1/4 layer in the symmetrically rolled sheet. Generally, asymmetric rolling increasesη. The effect of asymmetric rolling stems mainly from the change of the cold-rolled y especially (111) <112> component due to the induced through-thickness shear strain, but two large shear strain seems not benefit forηcomponent.(2){100} texture component. Asymmetric rolling affects recrystallization{100}<011> component through rolling{100}<011>, and its effect on{100}<001> component is similar to theηcomponent. Asymmetric rolling tends to lower the{100} component on the whole.(3){111}<112> texture component. Asymmetric rolling reduces recrystallization{111}<112> component of center layer and fast roll side layers by weakening cold rolling a and y, resulting in the decrease of recrystallization{111}<112> component generally.(4) a texture component. Asymmetric rolling reduces the recrystallization a of the center layer and fast roll side layers while increases it in the slow roll side, so that an overall slight effect on a occurs.4. Accoring to microtexture analysis, asymmetric rolling reduces recrystallization {111}<112> through lowering nucleation rate, and enhancesηby increasing the nucleation rate and growth rate (space). The asymmetric rolling of 1.125 speed ratio increase{100} component by the increase in nucleation rate in spite of the deceasing growth rate (space) with the increase of speed ratio. By means of lowering growth rate (space) and increasing nucleation rate, asymmetric rolling affects the recrystallization a texture very slightly.更多还原