研究了化学成分及偏析带对65Mn钢经淬火+中温回火处理后的组织性能的影响。结果表明:较高Si、Mn含量的65Mn钢的抗拉强度和硬度随淬火温度的升高呈逐渐增加的趋势更明显,但较低Si、Mn含量的65Mn钢具有更高的抗拉强度和硬度;Si、Mn含量高的65Mn钢淬透性强,组织为针状铁素体和细粒状渗碳体的混合物组成的回火屈氏体,而较低Si、Mn含量的65Mn钢,则得到回火屈氏体和多边形铁素体的混合组织;Mn偏析引起奥氏体相变过程中C的再分配,经过淬火+中温回火得到回火屈氏体+多边形铁素体组织,而原始组织均匀的65Mn钢则得到回火屈氏体组织;偏析带使热处理后65Mn钢的抗拉强度和硬度有所降低。 The effects of chemical composition and segregation zone on the microstructure and properties of 65Mn steel after quenching and tempering were investigated. The results show that the tensile strength and hardness of 65Mn steel with higher content of Si and Mn increase gradually with the increase of quenching temperature. However, 65Mn steel with lower content of Si and Mn has higher tensile strength and higher tensile strength, Hardness; 65Mn steel with high content of Si and Mn has strong hardenability, the microstructure is tempered troostite composed of a mixture of acicular ferrite and fine granular cementite, while 65Mn steel with lower Si and Mn content is And the mixed microstructure of tempered troostite and polygonal ferrite is obtained; the Mn segregation causes the redistribution of C during the austenite transformation, and the tempered troostite + polygonal ferrite structure is obtained by quenching and tempering at a moderate temperature 65Mn steel with uniform primary structure was obtained by tempering troostite microstructure; the segregation zone reduced the tensile strength and hardness of 65Mn steel after heat treatment.