针对第三代汽车用先进高强钢中的中锰钢组织性能控制开展研究，利用初始组织状态对中锰钢逆相变退火过程中的组织演变及最终的力学性能影响作用，通过优化冷轧变形和软化退火工艺来调控连续退火前中锰钢初始组织的位错密度、晶界取向差、变形储能及残余奥氏体分布等，从而掌控冷轧中锰钢中亚稳奥氏体的力学稳定性以及基体组织的形貌和力学特性，为进一步提高中锰钢的强塑积增加技术手段。本项目以连续退火生产工艺的含Al中锰TRIP钢为研究对象，拟采取实验研究和元胞自动机模拟相结合的方法，揭示初始组织状态对奥氏体逆相变和变形组织再结晶形核、长大的影响规律；构建可准确预测显微组织演变过程的元胞自动机模型；阐明奥氏体逆相变与变形组织回复、再结晶的相互作用规律；建立利用轧制参量调控中锰钢组织性能的理论基础，为优化轧制工艺提供理论依据，以此为指导试制出强塑积超过45 GPa%的冷轧中锰钢样件。

This research focuses on control of microstructure and mechanical properties of medium Mn steel which acts as one of promising candidates of the 3rd generation advanced high strength steels (AHSS) for vehicles. Based on the effect of the initial microstructure on microstructural evolution during the austenite reverted transformation (ART) annealing and resulting mechanical properties for medium Mn steels, controlling the initial microstructure characteristics before continuous annealing, e.g., dislocation density, misorientation distribution of grain boundaries, stored energy distribution of cold work and positions of retained austenite by employing optimized technology of cold rolling and softening annealing will be carried out. It can enable an effective controlling method of the mechanical stability of meta-stable austenite as well as the morphology and mechanical properties of matrix, which will add techniques to further increase the product of strength and elongation (PSE) of medium Mn steels. In this project, experimental test and numerical simulation by cellular automaton (CA) modeling will be combined to perform the research on medium Mn TRIP steels containing Al element for continuous annealing process. The study is aimed at revealing the effect of initial microstructure characteristics on nucleation and growth of reversed austenite and recrystallized ferrite grains, developing a CA model for the precise description of microstructure evolution, and further clarifying the interaction between reverted transformation of austenite and mechanism of recovery and recrystallization for deformed microstructure. On the basis of the abovementioned research, the theoretical foundation of controlling microstructure and mechanical properties of medium Mn steel utilizing the cold rolling parameters will be established, which provides theoretical reasons for optimizing rolling technology, and finally the trial-manufactured cold rolling medium Mn steels with the PSE value greater than 45 GPa% will be obtained.