Influence of roll diameter configuration of 20 high mill on roll shifting control characteristics of wide titanium strip cold rolling

In the production of wide titanium strips cold rolled by 20 high mill, when the diameter of the 1st intermediate roll is reduced, the work roll with a large roll diameter will be used to match it, which is called non-standard roll diameter configuration in this study. In order to master the control characteristics of the 1st intermediate roll shifting under non-standard roll diameter configuration, the coupled static model of roll system and strip is established by FEM, and the model is verified by using the corresponding relationship between the change of load roll gap and the change of titanium strip residual stress after cold rolling. The simulation results show that under the same rolling force, the contact stress peaks of non-standard roll diameter configuration in flat area and cone area of the 1st intermediate roll are about 1.44 times and 1.51 times of standard roll diameter configuration respectively. Compared with the standard roll diameter configuration, when the roll shifting amount increases, the longitudinal plastic strain of non-standard roll diameter increases most significantly in the range of 0-300mm from the titanium strip edge. Under the non-standard roll diameter configuration, increasing the roll shifting amount is more prone to occur the high-order buckle problem.