The effect of austenite deformation on bainite formation in an alloyed eutectoid steel

The isothermal bainite formation of austenite with and without pre-strain has been investigated in an alloyed eutectoid steel of Fe–0.80C–0.27Si–0.61Mn–0.15V (wt.%). It is found that the isothermal decomposition of deformed austenite within the regimes of bainite and finer pearlite is significantly promoted as the incubation period is remarkably shortened for small strain (e.g. 2%) and almost vanishes for strain larger than 5%. According to the TTT curves obtained for deformed (2%) and non-deformed austenite, Bs (Bs for isothermal bainite formation) for deformed austenite is about 10 °C higher than that for the latter. On the basis of the diffusion mechanism of bainite formation, the experimental results are explained by taking account of defects brought about by plastic deformation.