MATHEMATICAL-MODELING OF THE MEAN FLOW-STRESS, FRACTIONAL SOFTENING AND GRAIN-SIZE DURING THE HOT STRIP ROLLING OF C-MN STEELS

The logs for plain C-Mn grades from tour different hot strip mills wer e analyzed in order to calculate the mean flow stress developed at eac h stand. The calculation, based on Sims's equations, takes work roll f lattening, redundant strain, and the forward slip ratio into account. The stresses are compared with the predictions of a model based on an improved Misaka mean flow stress equation in which strain accumulation as well as the kinetics of static and dynamic recrystallization are f ully accounted for, A good fit is observed between the model predictio ns and the mill data, with agreement generally falling within the inte rval +/-15%.