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".