考虑辊缝变化的板带热轧动态理论模型

精准的轧制模型是生产优质带材的关键,目前常用的热轧模型仅适用于研究静态轧制过程.当面对变厚度轧制及轧机振动等动态轧制过程时,由于常用的静态模型不包含辊缝变化速度参数,因此其模型结构缺乏完整性.为了对动态轧制进行全面深入的研究,需要建立一个包含辊缝变化速度参数的动态轧制模型.基于Orowan方程,同时考虑辊缝变化速度对带...

Dynamic theoretical model of strip hot rolling considering change of roll gap

Accurate rolling model is the key to production of high-quality strips. Currently, the commonly used hot rolling model is only suitable for studying the static rolling process. When faced with dynamic rolling processes such as variable thickness rolling and rolling mill vibration, the model structure lacks integrity since the commonly used static model does not include the roll gap change speed parameters. In order to conduct a comprehensive and in-depth study on dynamic rolling, it is necessary to establish a dynamic rolling model which includes the parameters of roll gap change speed. Based on the Orowan equation, the dynamic velocity field model, the average deformation rate model and the force differential balance equation were established while considering the influence of roll gap change speed on the average deformation rate of strip and the length of deformation zone, and the analytical solution of dynamic rolling force was finally solved. A two-high experimental rolling mill was used to carry out dynamic rolling experiments. Comparing with the results of dynamic hot rolling experiments, the dynamic rolling model had high accuracy, which could provide theoretical guidance for precise preparation of dynamic rolling forces. Through analysis, it is found that when the roll gap change rate is zero, the model in this paper is the same as SIMS model. Change law of various process parameters for the dynamic rolling process in the model above was analyzed. The results show that the strip exit position deviates from the line of two work roll centers during dynamic rolling, and the deviation direction and size are directly affected by the size and direction of roll gap change speed. Under the same rolling schedule, when the roll gap is reduced, the rolling force is greater than that of static rolling, while roll gap is increased, the rolling force is less than that of static rolling. This is because the length of deformation zone and metal deformation rate in the roll gap are affected by size and direction of roll gap change speed. In addition, when the roll gap is reduced, the rolling force will decrease with the increase of the rolling speed.