Article révisé par les pairs
Résumé : This study deals with the influence of the austenite grain size and deformation state on the mechanism and kinetics of bainite transformation in several low-alloy steels differing by their C content. Nucleation and growth conditions are thoroughly modified when the austenite grain size becomes of the same order as the length of the individual bainitic ferrite platelets. As a consequence, the kinetics show some peculiarities. The austenite prior deformation also influences in a large way the morphology of the bainite - retained austenitc, microstructure.