| Along with automobile, the light industrial professions, home appliance and electrical production the unceasing raising that asked for board shape quality, shape of strip has become a most important quality problem in the production of hot strip rolling. Strip shape is mainly connected with the loaded roll gap in the strip production, so it can get strip with high geometry precision by controlling the roll gap. Roll gap control needs to know not only how much the center of roll gap changes under rolling pressure, but also the distribution of roll gap along the width of strip, it involves many factors. The thermal deformation, wear and elastic deformation of roll are the main three factors affecting the loaded roll gap control model. Among these, the thermal deformation of work roll plays significant role on the roll gap, the thermal expansion of roll in the middle plane may be better than 300μm, and the thermal deformation is changed continually in the whole rolling process, which causes the instability in production. And due to the complexity of its boundary condition, it is a difficulty for strip shape control technology to predict the roll thermal deformation well and truly during hot rolling. Therefore, the research on building a model for calculating thermal deformation has the important value of the theory and practice.According to heat transfer theory, associated with the practical practice of 1880mm hot rolling mill in Baosteel, and based on overall analysis to the roll heat transfer, mathematical equations of the coefficient of heat conduction in the roll, the coefficient of heat transfer of air and cooling water, quantity of heat inputting the roll had been deduced. Originated from the energy conservation law and equations of heat conduction, two roll two-dimension unsteady state's temperature fields had been established, including temperature field model of middle plane of roll and axial symmetry of roll. And the flow chart for calculating the thermal crown of roll was drawn. Aimed at the complexity of rolling and boundary condition, a series of experiments and tests were carried out on the spot of 1880mm hot rolling mill in Baosteel, including the measurement of surface temperature and thermal profile of work roll after stop rolling. Based on the rolling technological parameters, the temperature field and thermal deformation of work roll were calculated. And the measured data on spot were utilized to test the model to ensure the model's validity and feasibility.After using the model to simulate the temperature field and thermal deformation in hot rolling process, analyzed the transformation trend of the temperature at roll surface and center, and studied the development trend of total thermal crown and partial thermal crown in a rolling unit. Furthermore, the effect of roll material, width of strip, rolling rhythm, roll velocity, cooling water system parameters on transformation trend of work roll thermal profile were studied. This paper has provided improving the mathematical model of strip shape control and increasing accuracy of strip shape.
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