Research progress on formation mechanism of reversed austenite in maraging steels and its influence on properties

Traditional maraging steels are widely used in aerospace, high-end equipment and other fields due to their excellent strength and processability. However, traditional maraging steels suffer from insufficient plasticity and toughness due to the unfavorable morphology and distribution of internal precipitates. To address this limitation, formation mechanism, regulation paths of reversed austenite in maraging steels and its influence laws on material properties are reviewed systematically. Research shows that key alloying elements such as Ni, Co, Mo, and Ti significantly affect the nucleation and stability of reversed austenite through segregation and enrichment, promotion of precipitate formation, and other ways. Processes including solution-aging, additive manufacturing, and rolling can achieve precise regulation of volume fraction and morphology of reversed austenite by controlling temperature, stress, and element diffusion behavior. The multiphase structure formed by reversed austenite and martensitic matrix can realize the synergistic optimization of strength and toughness through the transformation-induced plasticity(TRIP) effect, and its volume fraction and distribution state show a clear quantitative correlation with the tensile strength, hardness, and plasticity of the material. By integrating thermodynamic and kinetic analyses, a complete correlation system of "alloying elements-precipitates-processes-reversed austenite-properties" is established, providing theoretical support for the composition design and process optimization of maraging steels. Meanwhile, it prospects the application potential in the fields of additive manufacturing of complex components, development of low-cost alloys, and materials serving in extreme environments, laying a foundation for the research and development as well as engineering application of high-performance maraging steels.