Analytical Modified Model of Cold Rolling Process and Investigation of the Effect of Work Roll Flattening on the Rolling Force

Cold rolling of steel is one of the most important metal forming processes so an accurate control of its parameters during the process is necessary. In this paper, the friction coefficient has been proposed as a function of cold rolling parameters such as forward slip, forward and backward tensile stresses ,strip thickness, static deformation, resistance of strip before and after rolling ,strip velocity before and after rolling and work roll diameters. A cold rolling model for computation of rolling pressure and force with varying friction coefficient and work roll flattening is proposed. The final results obtained from calculations were very close to the experimental results and there has been a good compliance with this method results and other researches and this is the advantage of this model. Finally the rolling forces in two stands with three passes were measured. So, the results demonstrated that an actual process in the two stand reversing cold mill by increasing the work roll flattening the rolling force increased considerably. Also, by increasing the tensile stresses at the end of the steel strip, the rolling force decreased.