Thermal stress analysis in hot rolling process

Abstract

In continuous hot slab rolling, it is important to know the temperature distribution within the strip along the length of the rolling mill because the dominant parameter controlling the kinetics of metallurgical transformations and the flow stress of a rolled metal is temperature. A mathematical model based on finite difference method is utilized to predict the temperature distribution and microstructural changes during the continuous hot slab rolling process. The effects of various parameters such as heat of deformation, the work-roll temperature, the rolling speed, and the heat transfer coefficient between the work-roll and the metal were all taken into account in the analysis. From the parametric analysis carried out, it was shown that the temperature in the deformation zone increases as the percentage reduction in the strip thickness and the rolling process, it affects the temperature distribution in the work-roll significantly, the heat generation on the strip-roll interface increases significantly when the percentage reduction in the strip exceeds a certain value. It was also shown that at low rolling speed, the temperature increase is uniform inside the strip and the roll and the maximum temperature of the strip occurs in the neighborhood of the strip centerline region.