【作者】 董志奎；

【导师】 张文志； 戚向东；

【作者基本信息】 燕山大学 ， 机械设计及理论， 2011， 博士

【摘要】 板凸度和板形是板带材的重要质量指标,板凸度和板形在线控制技术是板带材轧制生产中的核心技术,目前国内一直都是处于依靠巨资引进的状态。本文对带钢热连轧生产中板凸度和板形在线控制技术的相关方面进行了研究,将研究成果应用到工业实际生产中,取得了较好的应用效果,对于改变我国热连轧生产核心技术一直依靠引进的局面具有重要的现实意义。首先,对板凸度和板形计算模型进行了研究。板凸度和板形计算模型综合考虑了金属塑性变形模型、辊系弹性变形模型、轧辊热变形模型和轧辊磨损模型,可以模拟计算各种因素对带材板凸度和板形的影响。为了验证计算模型的正确性和准确性,以实际数据为例,对轧辊负载辊缝形状进行了动态模拟计算,轧辊使用不同时期的带钢出口厚度分布计算值与板凸度仪实测值吻合较好,表明模型具有较好的计算精度,从而为轧辊辊型曲线的优化设计及板凸度和板形在线控制的研究和应用奠定了基础。然后,对轴移式四辊热连轧机和普通四辊热连轧机轧辊辊型曲线优化设计进行了研究。轧后带材的板凸度和板形取决于轧件在负载辊缝中的三维变形,轧辊原始辊型对板带材板凸度和板形的在线控制具有重要的作用。本文基于不同的优化目标函数,对轴移式四辊热连轧机和普通四辊热连轧机精轧机组工作辊和支承辊辊型曲线分别进行了优化设计研究。其中,轴移式四辊热连轧机工作辊辊型采用燕山大学连家创教授发明的VCSW专利辊型,支承辊采用平辊身+辊端辊型的形式,生产实际应用表明,轧辊使用状况良好,配合自主设计的板凸度和板形在线设定控制系统,带钢在线板凸度和板形得到良好控制,辊型优化设计结果满足生产需要,优化设计的辊型已在生产中正式使用。普通四辊热连轧机工作辊采用余弦函数辊型,支承辊采用平辊身+辊端辊型的形式,实际生产应用表明,轧后带钢断面形状得到改善,板凸度达到了预期控制目标,支承辊端部疲劳剥落得到了较好遏制,优化设计的辊型已在生产中正式使用。最后,对热轧带钢板凸度和板形在线控制系统及数学模型进行了研究,并成功应用在工业实际生产中。完整的板凸度和板形在线控制系统主要包括:预设定控制系统、穿带自适应控制系统、弯辊力跟随轧制力前馈控制系统、板厚板形解耦控制系统、板凸度和平直度闭环控制系统以及模型自学习自适应系统。本文对上述各个子系统及其数学模型进行了详细论述,并对预设定控制系统、模型自学习自适应系统以及板凸度闭环控制系统在宁波钢铁1780 mm热连轧机中进行了工业应用,其中板凸度闭环控制系统采用BP神经网络模型。现场参数调试完成后进行了考核统计,配合优化设计的轧辊辊型,板凸度命中率达到96%以上,带钢在线板形状况良好,表明在线模型具有较好的适应性和控制精度,能够满足工业生产需要。现在,该自动控制系统已经在宁波钢铁1780 mm热连轧生产中正式投入使用。拥有独立自主知识产权的轧辊辊型专利技术及板凸度和板形在线设定控制技术的成功应用对于改变我国大型热连轧机核心技术主要依靠引进的局面、实现大型热连轧机核心技术国产化具有重要的意义。更多还原

【Abstract】 The crown and shape are important quality indicators of the plate and strip, the crown and shape online control technology is the core technology in plate and strip production, which we have been introduced from abroad for a long time. In this paper, strip crown and shape online control technology is studied, and the industrial applications achieved good results. The research results have an important significance in changing the situation of core technology about hot strip mill, which is depending on introducing from abroad.First, the calculation models of the strip crown and shape are studied. The calculation models include the metal plastic deformation model, the roll elastic deformation model, the roll thermal crown model and wear crown model, which can simulate with considering all kinds of factors. In order to test the correctness and accuracy of the calculation models, we conducted a dynamic simulation of load rolling gap with actual data,strip exit thickness distribution calculated and measured values are in good agreement. The results show that the calculation models have good calculate accuracy, it can establishe a foundation for optimizing the roll shape and studying on online control models of strip crown and shape.Second, roll shape optimization of roll shift 4-H hot strip mill and ordinary 4-H hot strip mill are studied. As the strip crown and shape depending on 3-dimentional deformation in load rolling gap, so, the original roll shape play an important role in online control of the strip crown and shape. Basing on different optimizing targets, we completed the work roll and back-up roll optimization for roll shift 4-H hot strip mill and ordinary 4-H hot strip mill. The patent VCSW which invented by Lian Jiachuang professor of Yanshan university is taken as work roll shape and flat body+edge curve is taken as back-up roll shape for roll shift 4-H hot strip mill. The industrial application show that the rollers have used in good condition, strip crown and shape are well controlled. The optimization results well meet the production requirements, the optimized rollers are used in production. The cosine curve is taken as work roll shape and flat body+edge curve is taken as back-up roll shape for ordinary 4-H hot strip mill. The industrial application show that the exit strip shape was improved, the strip crown achieved the expectation, the fatigue spalling of back-up roll edge was restricted. The optimization results well meet the production requirements, the optimized rollers are used in production.Third, the online control system and mathematical model of the strip crown and shape are studied and the industrial applications is carried out. Integrated online control system is presented based on preset control system, strip bite adaptive control system, bending force adjusting follow the roll force control system, discoupling control system of thickness and shape, closed-loop control system of strip crown and flatness and the self-studing and adaptive system. In this paper, every subsystem and its models are discussed, validated industry applications about preset control system, self-studing and adaptive system and strip crown closed-loop control system. The strip crown closed-loop control system used the BP neural network model. After actual parameters debugging, we have made a examination. The results show that the percentage of strip crown hits is more than 96%, the strip online flatness is good. From the results, we can know that online setting and closed-loop control system and models have good adaption and accurancy, which can meet industrial application. Now, the automatic control system has been formally applied. The successful application of the roll shape patent and strip crown and shape online control technology, which have independence intellectual property rights, will play an important significance in changing the situation of core technology and localizing the core technology about large-scale hot strip mill, which is depending on introducing from abroad for a long time.更多还原