A Detailed Study of the Transformation Stasis Phenomenon during the Isothermal Bainite Transformation in Mn Based Low Alloy Steels

Abstract

The effect of Mn on the “transformation stasis” phenomenon in low alloy steels during the isothermal bainite transformation has been studied both theoretically and experimentally. A so called Gibbs energy balance (GEB) approach, in which the dissipation of Gibbs energy due to diffusion of Mn inside interface is assumed to be equal to the available chemical driving force, is applied to model the transformation stasis phenomenon. The good agreement between experiments and GEB predictions demonstrates that the transformation stasis is caused by diffusion of Mn into the migrating austenite/bainitic ferrite interfaces. The GEB model clearly outperforms the diffusionless To model.