Effect of austenite grain size and bainite morphology on overall kinetics of bainite transformation in steels

Abstract

An attempt is made to rationalise some contradictory observations on the effect of austenite grain size on the overall kinetics of the bainite transformation in steels. Experiments have been carried out on two steels which show opposite effects of austenite grain size on the reaction rate. General equations describing the reaction rate are derived by taking into account the morphology of the bainite in each steel. The equations derived can explain the contradictory effects of the austenite grain size on the overall reaction rate. The results are also found to be in good agreement with the published data.