Kinetics of the Austenite-Ferrite Transformation with and without Applied Stress
The formation of ferrite (α) from austenite (γ) and vice versa, upon thermo-mechanical processing of steels, are phase transformations of great technological importance. Often these transformations occur in the presence of externally or internally imposed stress. This paper provides an overview of recent research on the quantitative analysis of the transformation kinetics of the γ®a and a®g transformations subjected to uniaxial compressive stress below the yield stress of g and a, based on the application of the high-resolution differential dilatometry and the modular model of transformation kinetics. The application of uniaxially compressive stresses leads to antagonistic effects on the transformation kinetics: the stress applied upon the γ®a transformation prompts the transformation, while it obstructs the a®g transformation. These results can be quantitatively discussed in terms of chemical driving forces and transformation-induced deformation energies.
Yves Bréchet, Emmanuel Clouet, Alexis Deschamps, Alphonse Finel and Frédéric Soisson
Y. C. Liu et al., "Kinetics of the Austenite-Ferrite Transformation with and without Applied Stress", Solid State Phenomena, Vols. 172-174, pp. 1207-1213, 2011