Numerical and analytical estimation of rolling force and torque in hot strip rolling

In this paper, both numerical and analytical method were developed for computing, in strip or plate rolling, the distribution of roll pressure, rolling force, and rolling torque (from which also rolling power can be estimated), assuming an homogeneous deformation of the rolled material. Unlike other similar models present in the literature, which solve the resulting rolling differential equation for the roll pressure, the model presented in this work solves the problem for the horizontal force. In this way, it is possible to avoid the calculation of the derivative of material flow stress curve, which is not always analytically easy and possible (i.e., point material flow stress data). The proposed numerical model is based on the friction law proposed by Chen and Kobayashi while the analytical one is based on the simple shear friction model and brings to useful analytical formulas for a quick calculation of rolling torque and force. Moreover, a relationship between the shear friction factor and Coulomb friction coefficient in rolling was found. The developed models show good agreement with experimental measures, in terms of rolling force and torque, found in literature.