【作者】 李俊洪；

【导师】 连家创；

【作者基本信息】 燕山大学 ， 机械设计及理论， 2003， 博士

【摘要】 板带轧机板形计算理论的研究是一个具有重要理论价值和实际意义的课题。本文全面分析了板形计算理论的两个主要组成部份——辊系变形（弹性变形和热变形）及金属三维塑性变形的研究现状，以板带轧机辊系变形数值计算法和样条函数拟合板带横向厚度分布为主要课题进行了更深入系统的理论和工业实际应用研究。本文首先对板带轧机辊系弹性变形数值计算法进行了理论研究，采用大型有限元软件MARC计算了板带轧机辊系弹性变形的特点及规律，分析了各种因素对辊系弹性变形的影响，采用有限条法建立了板带轧机辊系弹性变形计算模型，达到提高计算精度并减小计算工作量的目的。其次，本文建立了板带轧机工作辊横截面内温度场有限差分模型，采用样条有限条法建立工作辊轴对称平面温度场和热凸度计算模型，对工作辊热变形特性进行了全面的研究，提高了热凸度计算模型的计算精度。最后，采用B3样条函数拟合板带横向厚度分布，将求解辊缝中金属横向流动的变分法推广到存在局部高点的非对称任意轧制情况，定量考虑了热轧来料局部高点和轧件材质横向差异对冷轧带钢厚度和内应力分布的影响，提高了带材断面形状和板形的模拟精度。在此基础上，将求解金属横向流动的变分法与求解辊系弹性变形的有限条法相结合，建立了冷连轧机轧后断面形状和板形综合计算模型，在1220HC冷连轧机上进行的阶梯板试验以及在1420CVC冷连轧机上进行的试验验证了模型的正确性，表明本文建立的计算模型提高了轧后断面形状和板形的计算精度。在工业实际应用上，采用新的工作辊温度场和热凸度计算模型建立了1450热带钢连轧机精轧机组工作辊热凸度在线计算模型，该模型能具体考虑轧制规程、轧件规格、温度、轧制节奏、冷却水量及分布等因素对工作辊热凸度的影响，跟踪计算任意时刻各机架工作辊温度场和热凸度，该在线计算模型通过了生产现场的考核运行；结合1450热带钢连轧机改造需要，以工作辊温度场和热凸度计算模型为工具，对热带钢连轧机精轧机组工作辊冷却水量及分布进行了优化设计；以冷连轧轧后断面形状和板形综合计算模型为工具，对1220HC冷连轧机板形进行了模拟计算，对提高1200HC冷连轧机板形预设定精度有重要的应用价值；对1420CVC冷连轧机轧后断面形状和板形进行模拟计算，定量研究了热轧来料局部高点和局部硬度对冷轧带材厚度和内应力分布的影响，为研究消除或减轻冷轧钢卷局部隆起“起筋”现象的对策措施提供了依据。 <WP=5>更多还原

【Abstract】 The study on strip shape computational theory of strip mill is a subject which has important theoretical value and practical significance. This paper analyses comprehensively the present status of two main parts of the computational theory of strip shape, which are the deformation of rolls(elastic deformation and thermal deformation) and 3-D plastic deformation of metal. The numerical method of deformation of rolls and the analogue of strip lateral thickness distribution by the spline function are selected as main subject in this dissertation, and the research on theory and engineering application is carried out systematically and deeply.Firstly, this paper carries out theoretical studying to the numerical method of elastic deformation of strip mill’s rolls. The characteristic and regularity of elastic deformation of strip mill’s rolls are calculated using the large-scale FEM software MARC. The influences of different factors on elastic deformation of rolls are analyzed. It is the first time that the finite strip method is used to establish the elastic deformation model of rolls, which improves the calculating accuracy and decreases the amount of calculation. Secondly, the finite difference model of temperature field in work roll cross section of strip mill is established. It is the first time that the models on axisymmetric temperature field and thermal crown of work roll are established using the spline finite strip method. The thermal deformation characteristic of work roll is studied comprehensively, and the calculating accuracy of thermal crown model is improved. Finally, it is the first time that B3 spline function is used in the analogue of strip lateral thickness distribution. The variational method calculating the lateral flow of metal in roll gap is extended to the asymmetric rolling situations which have local high points. The influence of initial local high point of hot rolled strip and lateral diversity of strip material property on internal stress distribution and thickness of cold rolled strip are quantitatively researched for the first time. These improve the simulating accuracy of strip flatness and profile. Based on the above, the variational method calculating the lateral flow of metal in roll gap is combined with the finite strip method calculating elastic deformation of rolls, the model of compositely calculating flatness and profile of cold rolling strip is established. The experiments which are done on 1220HC cold strip continuous mill and 1420CVC cold strip continuous mill justify the correctness of the model. It is indicated that the model established in this paper improves the <WP=7>calculating accuracy of flatness and profile of strip.In the industrial application, the new calculating model of temperature field and thermal crown of work roll is adopted to establish the thermal crown on-line calculating model of work roll of 1450 hot strip continuous mills. This model can take the influence of the pass schedule, the specs of workpiece, the temperature, the rolling speed, the volume of cooling water and its distribution on work roll thermal crown into account. It can track and calculate the temperature field and the thermal crown of work roll at any time. This model has passed the examination of the production field. For meeting the needs of renovation of 1450 hot strip mill, the optimization design of volume and distribution of work roll cooling water was done using the calculating model of temperature field and thermal crown of work roll. Using the composite calculation model of flatness and profile of cold rolled strip, the strip shape of 1220HC cold strip continuous mill was simulated. This work has important application value to improve the strip shape presetting accuracy of 1220HC cold continuous mills. The simulating computations were conducted to the rolled profile and the rolled shape of 1420CVC cold continuous mills, the influence of initial local high point and local hardness from hot rolling on the distributions of thickness and internal stress of cold rolled strip更多还原