Reinterpretation for Modeling Carbon Partition by Thermo-Kinetics

Carbon partitioning plays a critical role in optimizing the stability of retained austenite to achieve a synergistic enhancement of strength and ductility in quenching and partitioning (Q&P) steels. Despite the availability of numerous carbon partitioning models, significant efforts remain necessary to comprehensively evaluate their underlying assumptions, applicability, and limitations, thereby enabling the rational design of materials at a more fundamental physical-metallurgical level. As the foundation of this review, thermodynamic assumptions and thermo-kinetic correlation theory are introduced to elucidate the classification of carbon partitioning models from a novel perspective. Guided by these thermodynamic assumptions, the carbon-constrained para-equilibrium model, CCEθ model (incorporating carbide precipitation), as well as para-equilibrium and local equilibrium models that account for interface migration are systematically evaluated. Finally, a novel thermo-kinetic correlation model for carbon partitioning is proposed, and its potential is critically discussed.