采用场发扫描电镜和EPMA电子探针研究了C-Si-Mn系双相钢锰配分行为及其对马氏体形貌、体积分数和力学性能的影响。结果表明：试验用钢0. 20C-1. 28Mn-0. 37Si在经双相区热处理后，在720℃的淬火温度下，随着保温时间的延长，锰元素由铁素体向奥氏体中的配分量不断增加，达到化学势平衡(即饱和状态)所需的保温时间为1500s；马氏体体积分数随着保温时间的延长而增加，达到饱和的时间是1300s；抗拉强度随着保温时间的延长而升高，当达到某一时间时，抗拉强度保持恒定。

Effect of Mn partitioning behavior on martensite morphology, volume fraction and mechanical property of C-Si-Mn dual phase steel was investigated by means of SEM and EPMA electron microprobe. The results show that with increase of the annealing time, the content of Mn element of the experimental steel 0. 20C-1. 28Mn-0. 37Si partitions from ferrite to austenite is increasing in quenching temperature about 720℃ after heat treatment in dual phase region, The holding time required for 1500s when reached chemical potential equilibrium (saturation); with the annealing time the volume fraction of martensite is increasing, the saturation time of volume fraction was 1300s; with the holding time the tensile strength is increasing, and when it reached a certain time, the tensile strength remains constant.