宽幅电工钢热轧板形控制研究

发布时间：2018-01-30 03:15

  本文关键词： 电工钢 热轧 板形控制 辊形 有限元分析　出处：《北京科技大学》2016年博士论文　论文类型：学位论文

【摘要】：电工钢是重要的金属功能材料,板形是电工钢的关键质量指标。热轧是生产电工钢的重要流程和关键环节。电工钢热轧生产具有大量同宽自由规程薄板轧制特点,且板形质量要求更趋严苛。电工钢大量同宽自由规程轧制过程还存在严重的轧辊磨损和剥落问题,更加制约了板形质量的改善。为提高宽幅电工钢热轧板形质量,本文以近年新建的国内电工钢产量最大的热连轧机为研究对象,通过基础实验、有限元仿真、理论解析、工业试验和生产应用相结合的方法,开展了宽幅电工钢热轧板形控制研究,取得的成果如下：(1)通过热模拟实验研究了电工钢高温压缩过程的流变力学行为。针对电工钢热压缩过程中在单相区表现出的应变硬化和高温软化特征以及在两相区表现出的应变硬化和低温(相变)软化特征,分别建立了电工钢热塑性本构模型,该模型可用于准确预测电工钢高温压缩过程中的材料力学属性。(2)建立了电工钢轧制过程有限元仿真模型,并将本构模型应用到了仿真计算中。通过有限元仿真研究了宽幅电工钢热轧过程多种因素影响下的板形变化规律。对电工钢生产实际中存在的不同形式的横向温度差进行了研究,发现带钢横向温度差特别是当其存在于两相区轧制时可引起电工钢凸度、楔形和浪形的明显变化,从而造成电工钢热轧板形难以控制。(3)电工钢热轧中存在严重的轧辊磨损和剥落问题。分析了电工钢大量同宽自由规程轧制条件下轧辊磨损特征,计算指出轧辊磨损会使板形凸度增大并降低弯辊力调控功效；提出了工作辊磨损的多参数表示方法,从而可有效衡量工作辊磨损对板形的影响趋势;通过轧辊完整服役期内接触应力计算并结合裂纹和断口检测,指出轧辊磨损造成的严重应力集中在轧辊剥落中起主导作用。(4)为提高宽幅电工钢板形质量,提出了电工钢热轧板形控制方法。通过理论分析和工业试验研究了高速钢轧辊、正弦形式窜辊策略和润滑轧制对轧辊磨损的改善效果,研发了对大宽度范围变化的带钢均具有良好板形控制能力的UVC变凸度工作辊和适应大量同宽轧制条件的VCR变接触支撑辊。成果投入工业试验和连续稳定应用累计轧制590余万吨,取得了轧辊磨损明显改善、轧辊剥落未再发生和板形质量明显提高的稳定生产实绩。
[Abstract]:Electrical steel is an important metal functional material. Strip shape is the key quality index of electrical steel. Hot rolling is an important process and key link in the production of electrical steel. The hot rolling of electrical steel has a large number of characteristics of the same width free schedule sheet rolling. And the shape quality requirements are more stringent. A large number of electrical steel rolling process of the same width free schedule there is a serious roll wear and spalling problem. In order to improve the shape quality of wide width electrical steel hot rolling, this paper takes the hot strip rolling mill which has the largest output of electrical steel in recent years as the research object, through the basic experiment, finite element simulation. Based on the theoretical analysis, industrial test and production application, the shape control of hot rolling of wide width electrical steel was studied. The results are as follows:. The rheological behavior of electrical steel during high temperature compression was studied by means of thermal simulation experiments. The strain hardening and softening in single phase region and strain hardening in two phase region were studied during hot compression process of electrical steel. Chemicalization and hypothermia (. Phase change) softening characteristics. The thermoplastic constitutive model of electrical steel is established, which can be used to accurately predict the mechanical properties of materials in high temperature compression process of electrical steel. (2) the finite element simulation model of electric steel rolling process is established. The constitutive model is applied to the simulation calculation. Through finite element simulation, the rule of shape change under the influence of many factors in the hot rolling process of wide width electrical steel is studied. The different kinds of transverse temperature existing in the production of electrical steel are studied. The degree difference is studied. It is found that the transverse temperature difference of strip steel, especially when rolled in the two-phase zone, can cause obvious changes in the crown, wedge and wave shape of electrical steel. Thus, it is difficult to control the shape of electric steel hot rolling. 3) there are serious roll wear and spalling problems in electric steel hot rolling. The wear characteristics of electric steel roll under a large number of free schedule rolling conditions of same width are analyzed. It is pointed out that roll wear will increase the profile crown and reduce the control effect of roll bending force. The multi-parameter expression method of work roll wear is put forward, which can effectively measure the influence trend of work roll wear on flatness. Through the calculation of the contact stress during the complete service period of the roll, combined with the crack and fracture detection, it is pointed out that the serious stress caused by the roll wear mainly plays a leading role in the roll spalling. 4) in order to improve the shape quality of the wide width electrical steel. The shape control method for hot rolling of electrical steel was put forward, and the improvement effect of high speed steel roll, sinusoidal roll channeling strategy and lubricating rolling on roll wear was studied by theoretical analysis and industrial test. UVC variable crown work roll with good shape control ability for strip with wide width range and VCR variable contact support roll suitable for a large number of same width rolling conditions have been developed. The results have been put into industrial test and continuous stability. Application of rolling more than 59 million tons. The stable production performance has been achieved, such as the obvious improvement of roll wear, the non-recurrence of roll spalling and the obvious improvement of shape quality.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG334.9
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本文编号：1475135