The hot strip mill as an experimental tool

The occurrence of carbonitride precipitation during the short interpass tim es associated with hot strip rolling is considered, together with the inter action between precipitation and static recrystallization under these condi tions. The characteristics of work hardening and of strain accumulation at the high temperatures (850 to 1050 degrees C) involved in strip rolling are described. Expressions are introduced that specify the kinetics of softeni ng (by static or metadynamic recrystallization) during the interpass interv al in various grades of steel. Using these kinetics in an appropriate mill model, the mean flow stresses pertaining to various mill stands are predict ed. 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 kine tics. This is one way in which a hot strip mill can be used as an "experime ntal tool".