对屈服强度700 MPa级超高强度热轧钢带进行了700~800℃退火处理,通过光学显微镜、扫描电镜、透射电镜及性能测试对不同温度退火后试验钢的组织性能进行分析。结果表明,700~800℃两相区退火时,组织为铁素体和游离渗碳体;随退火温度升高,钢中游离渗碳体数量增加,组织均匀性提高;钢的强度和硬度急剧降低,伸长率和冲击性能提高,冷弯开裂几率降低。 The 700 MPa ultra-high strength hot-rolled strip with yield strength of 700 MPa was annealed at 700-800 ℃. The microstructure and properties of the test steel after annealing at different temperatures were analyzed by optical microscope, scanning electron microscope, transmission electron microscopy and performance testing. The results show that the structure is ferrite and free cementite during the annealing at 700-800 ℃. With the increase of annealing temperature, the amount of free cementite increases and the homogeneity of microstructure increases. The strength and hardness of steel rapidly increase Lowering, elongation and impact properties improve, cold cracking probability decreases.