Comparison of Rolling Forces and Enlargement of Hot-rolled Strips Obtained from Experimental, Analytical and Simulation Models

Abstract

During rolling processes, the strain on the thickness direction of a material inevitably results in dimensional changes in width and length. Knowledge of the behavior of strains and stresses acting during hot rolling process becomes indispensable, as it allows to estimate the resulting geometry and optimize process conditions. This study compares the deformation and the rolling forces obtained through experiments, analytical models and finite element simulation. To this end, SAE 1020 steel was hot processed in a duo rolling mill for reductions of 13%, 17% and 21% in height. Based on the performed experiments, a microstructural analysis was performed and a numerical model was proposed. Furthermore, these results were compared with different analytical models to determine the process characteristics. The numerical model obtained the better approximation among the approached models, with a discrepancy in the order of ±0.005mm in comparison with the measured values of the real deformation in width direction, what represents a relative error of 0.03%. Furthermore, the calculated force through simulation presented results closer to the ones measured experimentally presenting a good fit for the proposed model and hot rolling process. Finally, the processed microstructure migrated from elongated to equiaxed grains arising from the dynamic recrystallization mechanism. This study shows that numerical simulation had become an important tool to assess the development of rolling processes as they can predict the final geometry and forces with good correlation with real processing conditions.