Research On Thin Strip Shape Control Technology Of Cold Rolling

Based on the project of "Research on Improving Shape Control Accuracy of Two-stand Reversing CVC Four-high Cold Rolling Mill" in Jinan Iron and Steel, for the secondary data is unreasonable, especially because the set value of roll shift is too large, the shape is bad and easy to come out big medium waves, the theory, mathematical model control strategy of the strip shape control system was researched systematically in the paper. The main works are shown as follows:(1) The mathematical model of roll elastic deformation was set up by the influence function method, the main emulate parameter was fixed, the research was done on the shape adjusting characteristics of strip width change, the roll diameter, the work roll shifting and the bending force to know the changed principle of the roll gap crown;It shows the character and principle of extra-width mill in the control of strip shape.(2) The shape control mathematical model of specific physical meaning was set up. the roll gap were divided into the unload roll gap crown and deforming roll gap crown to simplify the shape control model structure. The deforming gap crown was influenced by rolling force, roll bending force, strip width, roll diameter and unload roll gap crown. The load distribution roll gap model was developed to describe the relationship between the roll elastic deformation and the influencing factors. The method was provided for determining the uniform load distribution roll gap model coefficient. Based on the volume conservation, the strip shape forecast model was deduced by ignoring the material transverse flow and secondary deformation between mills.(3) The control strategy of the shape control system was researched. A new kind of shape control strategy was proposed to enhance the hit rate of the target strip crown under the condition of guaranteeing the strip flatness quality. The new strategy can increase the shape control capability to utmost extent. The setup calculation mathematical model of each shape control actuator was established. According to the relationship between the shifting position of the work roll and the roll gap crown, the iterative calculation method was established to determine the shifting position of the work roll. In accordance with the Crown calculation model, principle was given on how to use the bending and shifting. Cold rolled strip shape control simulation software was also setted up to instruct the actual operation.