MODELING AUSTENITE FLOW CURVES IN LOW-ALLOY AND MICROALLOYED STEELS

A model has been developed to predict the austenite flow curves of low alloy and microalloyed steels. The model consists basically of two ex pressions for stress, as a function of strain, temperature, strain rat e and the chemical composition of the steel. The first predicts the ha rdening and dynamic recovery region and the second predicts the soften ing caused by dynamic recrystallization, the algebraic sum of both exp ressions predicting the complete flow curve. The model's different par ameters are a function of the dimensionless parameter ZIA of Sellars a nd Tegart's equation, which in turn has been modelled not only as a fu nction of temperature and strain rate but also as a function of the ch emical composition. In this way one single model may be applied to any hot deformed steel whose composition is the same as or similar to tho se studied.