Extension of Isothermal Time-Temperature Parameters to Non-isothermal Conditions: Application to the Simulation of Rapid Tempering

A phenomenological method for constructing non-isothermal, generalized time-temperature parameters (GTT parameters) is presented. An analysis of the relationship between the various traditional isothermal time-temperature parameters has verified that the generalized Dorn-parameter is regarded to be the sole non-isothermal complex parameter to which a rigorous, physically well-founded interpretation is attributed. Possible applications of GTT parameters are illustrated by examples concerning the prediction of hardness change in quenched steels during rapid tempering treatments.