Research On Predictive Control Of Work Roll Temperature Field And Thermal Deformation During Rolling Process Of Four-high Cold Rolling Mill

The thermal roll shape of the work roll during cold rolling is a key element influencing the quality of the strip.Because the environment of the work roll is very complicated and the thermal boundary conditions are difficult to determine,the accurate prediction of the temperature field of the work roll has always been a weak link in the study of thermal roll shape.Therefore,in the process of cold rolling,accurate calculation of the heat transfer in each area and establishment of the corresponding finite element model are of great value to the predictive control of the thermal roll shape.The main heat sources in the rolling zone are the heat of deformation of the strip and the friction heat of the rolling interface.In this paper,according to the characteristics of cold rolling,the deformation work model of the strip was established,and the deformation heat generated by the strip was calculated;the pre-displacement-sliding friction theory was used to establish the frictional heat model of the contact surface,and the frictional heat generated by the rolling interface was calculated.With the help of the heat transfer law between the contact surface and the boundary environment,a heat transfer coefficient model between them was established,and the heat input and output of the roll surface were calculated.In view of the complex thermal boundary conditions of the work roll and the low accuracy of the traditional two-dimensional model,the complex thermal boundary conditions were simplified into thermal loads uniformly arranged along the axial direction.Using Solidworks three-dimensional software to draw geometric model of the work roll,and then the geometric model was imported into ANSYS finite element software.After adding initial conditions and boundary conditions,the high-precision 3D finite element model of the work roll was constructed.Through the analysis of the temperature and thermal deformation distribution diagram of the work roll at different times,the temperature change law and thermal deformation law of the work roll were clarified.The influence of the concentration,temperature and flow rate of the emulsion on the temperature of the work roll,and the control effect of the segmented cooling on the roll shape are respectively analyzed.Taking the 1850 four-high cold rolling mill of an enterprise as the research object,the temperature and deformation of the work rolls were measured.Comparing the results of the simulation calculation with the field data verifies the correctness of the simulation results.So as to provide a theoretical basis for improving the prediction accuracy of the thermal roll curve.