Research Of Flatness Control Characteristics And Work Roll Shape Optimization For Pc Rolling Mill

As the PC rolling mill for improving the shape and controlling the rolling crown has a very significant effect, it is widely used in the hot-rolled and cold- rolled strip. Because of the rolls pair crossed, the rolling process has a greater axial force. In the case of high-speed rolling, rolling mill stability is lower than the regular four-high mill to restrict the strip product quality and rolling production efficiency. In addition, as the existence of roll-bending force speeds up the work roll surface wear and lower the work rolls and the bearing life. Therefore, how to improve service life of the work rolls, effectively reducing the cross-angle and roll-bending force to ensure a good shape, these research for the promotion of the PC mill and the application of PC mill automatic shape control in our country has important theoretical significance and practical value.Firstly, use difference method to solve the metal plastic deformation. According to the character of the deformation zone on pair cross rolls, which is different from the regular four-high mill. Influences of normal stress and shear stress in rolling direction, width direction and thickness direction are considered. Establish the rolling force calculation model of PC mill. On the rolling force model is validated by the experimental data to prove the accuracy of the model.Secondly, use influence function method to solve elastic deformation of rolls for PC mill. Considering the force and deformation of the work roll and backup roll and roll offset between them in horizontal and vertical directions, establish the rolls elastic deformation of the roll force and moment balance equation, force -displacement relationship equation and deformation coordination equation. Then, establish the PC mill shape and crown control model, analyzing the shape control features of the PC mill. It is primarily impact of cross-angle and roll-bending force on the rolling force, the former tension and the gauge distribution.Finally, according to PC mill characteristics of the production process, taking into account to reduce cross-angle and roll-bending force, taking the roll-type curve parameters, cross-angle and roll-bending force as the variables, to ensure a certain percentage crown as work roll optimization of the objective function, taking a 1880 hot-rolling mill to roll three typical cases of narrow, medium and wide width products, complete the optimization of the fourth frame work roll curve.