Modelling of axial thrust force between rolls in strip mill

Theoretical predictions and engineering practice indicate that roll crossing in strip mills can generate an excessive axial thrust force between rolls, often resulting in roll bearing failures and a lower strip surface quality. Although this effect is important in design of strip mills and manufacturing, the existing literature refers only to simple formulas and manual measurements for evaluating this axial thrust force. In this work, a novel approach to model the axial thrust force considering tangential deformations of the rough surface layer and the matrix is proposed to calculate the axial thrust force for various typical strip mills. In addition, data from an industrial test rig at the production site taken to examine the real-time axial thrust force during roll crossing. The results indicate that under light load conditions, the axial thrust force can be accurately predicted by considering only the tangential deformation of the rough layer surface, whereas for heavy loads conditions, the tangential elastic deformation of the matrix must be taken into account as well. The axial thrust force approaches sliding friction force limit for crossover angles smaller than 0.1°. In general, the axial thrust force grows with increasing crossover angle, which is confirmed by both theoretical and experimental results.