Research About The Rolling Temperature Model And Its Influencing Parameters Of Cold Tandem Mills

With the development of modern technology, the quality of the cold rolled strip should be kept improving to satisfy the user's demands. It is indicated that in order to improve the quality of the cold rolled products, how to get good surface quality and strip shape by controlling the rolling temperature properly during the rolling process has become one of the most important problems in the field.On the basis of the systematical analysis on the main factors that cause the temperature change of the rolled piece and rollers during the process of cold tandem rolling, this paper made a brief introduction of the temperature change in the rolling process and its analytic methods. Meanwhile, it took the elastic deformation of both the rollers and the rolled piece into account. And the length and the average rolling force of every area were precisely calculated by dividing the deformed area into entry elastic area, plastic area and outlet elastic area, on the basis of which the two main factors deformation heat and friction heat that caused the temperature change in the cold tandem rolling process were calculated.According to the practical parameters, the influences of the initial temperature of the hot rolled strip, heat-transfer coefficient, the air cooling heat-transfer coefficient between the last stand and the coiling machine were analyzed and the figures of influencing rules were made.In the process of the temperature analyzing, on the basis of W.L.Roberts model, a new mathematical model of predicting the temperature of the strip from the entry to the outlet were established by combining the features of tandem rolling and the calculation of the deformation heat and the friction heat and taking the emulsion heat-transfer coefficient as a variable. Temperatures of representative coils were measured and compared with the predicted values ofthe temperature calculating model and its forecasting precision was verified.On the basis of the temperature model above, the software of temperature prognostic and the interface of the software were individually established by Fortran and Visual Basic. This software is very simple and convenient to work with and it has been used practically on 1220mm five-stand cold tandem mills. Conscious pre-control of the temperature and good effectiveness which reduced the influence of the temperature on the surface quality and shape of the strip to a great extent were accomplished. It has been well accepted by the field.