为探究基于中温连续冷却工艺制备高强塑性中锰钢的可行性，以0.2C-3Mn-1.5Si (质量分数，%)中锰钢为研究对象，利用SEM、EBSD等表征手段和力学性能测试方法，研究了预先Mn配分对低Mn含量中锰钢中温连续冷却贝氏体相变及残余奥氏体体积分数的影响机理。结果表明，利用中温连续冷却过程中发生的无碳化物贝氏体相变可在中锰钢中获取残余奥氏体。通过在临界区预先进行Mn配分处理，可获得层片状富Mn奥氏体。在后续中温连续冷却过程中，贝氏体相变被限制在过冷奥氏体层片内发生，获得由薄膜状残余奥氏体、贝氏体铁素体和临界铁素体组成的多相细晶组织。通过预先Mn配分中的Mn富集和贝氏体相变中C富集的作用，大幅提升了低Mn含量中锰钢中残余奥氏体的体积分数，同时提高了中锰钢的强塑性。

In the development of third-generation advanced high-strength steels, achieving a balance between strength and ductility while minimizing alloying and production costs is critical. Among the promising candidates, medium Mn steels (MMnS) have the desired design flexibility for achieving a certain amount of metastable austenite, thereby exhibiting an enhanced transformation-induced plasticity (TRIP) effect. Owing to the weakened alloying effect in low-Mn content MMnS, more efforts should be devoted to enhancing the stability of austenite during intercritical annealing. This study explores the possibility of developing high-strength, high-ductile MMnS via continuous cooling from medium temperatures. A 0.2C-3Mn-1.5Si (mass fraction, %) MMnS was selected to analyze the influence of Mn pre-partitioning on bainite transformation and the volume fraction of retained austenite in low-Mn content MMnS using various characterization methods, including SEM and EBSD, as well as mechanical property testing methods. The results indicate that the carbide-free bainite transformation occurring during the medium-temperature continuous cooling enables the acquisition of retained austenite in MMnS. Mn-rich austenite lamellae can be initially produced via Mn pre-partition during intercritical annealing. Subsequently, bainite transformation is restricted to occur within the undercooled austenite lamellae in the medium-temperature continuous cooling process, resulting in a refined multiphase microstructure comprising film-like retained austenite, bainitic ferrite, and intercritical ferrite. The volume fraction of retained austenite in low-Mn content MMnS substantially increases because of the enrichments of Mn and C from Mn pre-partition and bainite transformation, respectively, thereby enhancing the strength and ductility of MMnS.