Analysis of Plate Bending in Coilbox by Finite Element Method

Using finite element method (FEM), the results of bending conditions of the intermediate plate at the bending rolls of a coilbox between the roughing and finishing stands in a hot strip mill were obtained. The intermediate plate was coiled in a coilbox, which effectively overcame the problem of temperature drop by reducing surface area exposed to radiant heat loss during the waiting period. Different states of the plate in the coilbox were simulated by FEM, and the mathematical model of the bending rolls was established, which was in accord with the simulation results that the plate was coiled. As the bending shape of the front end of the intermediate plate is crucial to coiling process, the curvatures of the plate were predicted through FEM. In addition, the roll diameter and arrangement affect the optimum curvature, thus the parameters for bending rolls were determined without many adjustments. The developed bending model has been applied to actual coilbox in plant.