The hot strip mill as an experimental tool

The characteristics of work hardening and of strain accumulation at the high temperatures (850–1050°C) involved in strip rolling are described. A method is outlined for quantifying the kinetics of softening (by static or by metadynamic recrystallisation) during the interpass intervals in various grades of steel. Using these kinetics in an appropriate mill model, the mean flow stresses pertaining to various mill stands are predicted. These values are compared with the measured ones derived directly from mill logs. It is shown how discrepancies between the predicted and measured values can be used to improve the accuracy of the expressions for the kinetics. It is in this way that a hot strip mill can be used as an ‘experimental tool’.