Some Aspects of Bainite Transformation in Fe-Based Alloys

The mechanism of the bainite transformation in carbon containing steels was discussed after presenting our recent experimental results; (1) the bainite transformation has its own C-curve, (2) incomplete phenomenon is a general feature of the bainite transformation, (3) bainitic fenite grows to a limited size, and (4) bainitic ferrite is highly supersaturated with respect to carbon. It was examined what kinds of interphase boundary structures and carbon concentration gradients in the vicinity of the transformation interface are possible to expIain the experimental results. It was concluded that the bainite transformation should be regarded as the transformation that occurs by the movement of a glissile interphase boundaq and requires diffusion of interstitial carbon atoms at least to a certain extent in the nucleation and growth stages.