在不同温度下对Ti-Mo低碳钢进行等温转变,对热轧板进行力学性能检测,利用扫描电镜、透射电镜、选区电子衍射等方法进行组织观察,同时分析了相间析出粒子的形貌、尺寸和分布规律.结果显示,随着等温温度降低,钢的强度提高,延展性降低,屈强比增大.在透射试样中观察到两种不同形态分布的相间析出碳化物:平面型相间析出和曲面型相间析出.相间析出碳化物的平均直径为4.30nm,平均纵横比为1.375.在650℃等温保温1 h时,相间析出强化对铁素体相强度的增量在400MPa以上. The isothermal transformation of Ti-Mo mild steel was carried out at different temperatures. The mechanical properties of hot-rolled sheet were tested. The microstructures were observed by scanning electron microscopy, transmission electron microscopy and selected area electron diffraction. Meanwhile, The results show that with the decrease of isothermal temperature, the strength of the steel increases, the ductility decreases and the yield ratio increases. Two kinds of precipitated carbides with different morphologies are observed in the transmission samples: Precipitation and surface phase precipitation between the phase precipitated carbide average diameter of 4.30nm, the average aspect ratio of 1.375. When incubated at 650 ℃ isothermally 1h, phase precipitation enhanced the increase in the ferrite phase strength of 400MPa or more.