A comprehensive analysis of the strip rolling process

The existing theories of strip rolling make wide use of the hypotheses of homogeneous deformation, constant coefficient of friction or friction factor, and parabolic roll deformation. Temperatures of the strip and rolls are usually predicted by using over-simplified analytical solutions or complicated numerical techniques. From these models, a number of general conclusions have been drawn. Although roll separating force, roll torque, and temperatures can be predicted with reasonable accuracy, forward slip has never been successfully calculated using these existing models. Furthermore, a discontinuity in the interfacial stress distribution is found as a consequence of the use of a homogeneous deformation assumption.;An advanced slab model which considers the inhomogeneity of strip deformation was developed. The redundant work effect, elastic deformation of the strip, and roll flattening were incorporated into this slab model to establish the capability of accurately predicting roll separating force, roll torque and forward slip. Also, for the first time, friction in the sticking zone was determined analytically using a no-slip boundary condition.;A straightforward scheme of calculating temperatures was developed based on the high Peclet number nature of the process. Computational time is reduced significantly compared to other methods. The effect of roughness on heat transfer was also studied. The results can be adapted to the boundary friction regime, the mixed lubrication regime, and the hydrodynamic regime to determine temperatures.;Stresses developed in the work roll were calculated through introducing a simple thermal stress model and a more precise mechanical stress model. The mechanical stress model was derived based on the patch solutions for tractions of isosceles form. This eliminates the infinite shear stress at the corners of patch which occurs when using uniformly distributed tractions.;The results of the computer simulation were compared with experimental measurements of roll separating force, roll torque, forward slip, and strip temperature. The simulation results are in excellent agreement with the experimental measurements.