Study On Flatness Target Curve Optimization Theory Of 20-high Copper Strip Mill

The capacity and quality of sheet and strip is a momentous mark of the industrial development level,especially the copper strip.Among the copper strip production equipments,the 20-high mill has been one of the most representative equipments,the SUNDWIG 20-high mill has been favored by the manufacturers because of its various and flexible means of flatness adjustment,and other characteristics.Therefore,it is significant to explore flatness law of 20-high mill.Based on the existing flatness prediction model and the flatness target curve theory,the detailed tasks of this paper are as below:(1)In the elastic deformation model of roll system,a new method for division of roll units has been proposed by combining Contact Element Model and the traditional division method.This new method can not only calculate the deformation of the side of the work roll but also predict the contact phenomenon of the side of the work roll.In addition,in view of the bending deformation function of the back-up roll set in SUNDWIG 20-high mill,its deformation formula is fitted with the finite element method.Then the flatness is evaluated by the result of the obtained formula.The simulation results show that the influence of the middle saddle on the flatness and thickness is greater than that of the side saddle.In addition,even if the two sides of the center of the support roll set apply symmetrical saddle shift,the influence on the thickness and flatness is asymmetric.(2)Aiming at the defect that the target crown of each pass cannot be controlled quantitatively in the traditional target curve formulation of cold rolling,a new target curve formulation method considering target crown has been proposed.Specifically,the target crown of each pass can be set by combining the total proportional crown change in hot rolling field to each pass and the instability discrimination model in cold rolling field.The way of this paper is compared with the traditional method to verify its rationality,and then the flatness target curve is simulated under different target crown of the final pass.The results show that the crown after rolling of each pass can be controlled quantitatively by selecting the target crown of the final pass in reason.(3)The elastic deformation model of roll system,the metal plastic deformation model and the discriminant model are compiled by Visual C++.The first intermediate roll's axial shifting and the bending deformation function of the support roll set are simulated,and the flatness law can be obtained.The front panel of the calculating program is compiled by Visual Basic.Flatness and thickness can be showed in the front panel straightly.