Abstract
The thermal histories of steel strips in a multi-bending process after hot rolling were clarified by numerical analysis in order to investigate the appropriate conditions for grain refinement. The temperature oscillates cyclically at the strip surface, whereas the temperature amplitude is relatively small at the center of thickness. The temperature distribution in the strip thickness direction depends on the transfer speed and cooling conditions, that is, air or water cooling. In industrial production, water-cooling equipment would be necessary in order to cancel the accumulated heat generation caused by bending deformation and to maintain the strip temperature in the appropriate range for grain refinement.
