Dongyun Sun, Hao Guo, Qitian Ye, Haoran Nie, Xinyao Zhang, Xiaowen Sun, chen Chen, peng Zhang, Zhinan Yang, Fucheng Zhang
Hardenability is a key indicator governing the microstructural uniformity and overall properties of steels, and its optimization is crucial for the development of high-performance steel grades. This review summarizes the physical nature of steel hardenability, standard characterization methods, multiscale influencing factors, and corresponding control strategies. By systematically analyzing the effects of alloying elements, austenitization processes, and metallurgical quality on hardenability, the underlying mechanisms are clarified, highlighting the critical roles of alloying element dissolution, grain boundary segregation, and phase transformation kinetics in improving hardenability. Furthermore, recent advances in computational approaches for hardenability prediction, including first-principles calculations, finite element simulations, and machine learning models, are discussed. The current challenges in understanding and optimizing steel hardenability are critically assessed, and future perspectives toward multiscale coupled design and digital closed-loop control are proposed.