Abstract: The steelmaking process of 700 MPa microalloying steel (/% : 0.05C, 0.18Si, 1.80Mn, 0.010P, 0.003S, 0.15Mo, 0.l0Ti, 0.075Nb, 0.035V, 0.030Al, 0.0020Ca) is 240 t BOF-LF-2150 mm slab casting. The structure and mechanical properties of hot-rolled 10 mm strip of 700 MPa microalloying high strength steel air-cooling processcoiling at 600℃. and direct sampling air-cooling for 3.7 h to ambient (25℃ ) and slow-cooling process-coiling at 600℃ and coils stacked slow-cooling for 36.2 h to ambient (25℃)are observed and tested by using optical microscope, scanning electron microscope, energy spectrometer and tensile tester. Results are obtained that with slow-cooling process the amount of bainite in steel strip is relatively less, the steel strip has higher yield strength (732~740 MPa) , lower tensile strength (793~799 MPa) and larger elongation (21.0% 〜23.0% ) ； and with air-cooling process the amount of bainite in steel strip is rather more, the steel strip has lower yield strength (647〜654 MPa) , higher tensile strength (811〜831 MPa) and rather lower elongation (15.0%~17.0% ). Comprehensive consideration, the mechanical properties of steel strip with slow-cooling process are better than that with air-cooling process.

摘要： 700 MPa微合金钢（/%:0.05C,0.18Si,1.80Mn,0.010P,0.003S,0.15Mo,0.10Ti,0.75Nb,0.035V,0.030Al,0.0020Ca）的冶炼工艺为240 t BOF-LF-2150 mm板坯连铸。通过利用金相显微镜、扫描电镜、能谱仪和拉力试验机试验了700 MPa级微合金高强钢轧后,10 mm钢带从600℃卷取时直接取样经3.7 h冷却至室温（25℃）的空冷工艺,和钢带600℃卷取后并堆放在一起经36.2 h缓慢冷却到室温（25℃）的缓冷工艺的组织和性能。结果得出缓冷工艺下,钢带的贝氏体较少,屈服强度高（732~740 MPa）、抗拉强度低（793~799 MPa）、伸长率大（21.0%~23.0%）;空冷工艺下,钢带的贝氏体较多,屈服强度低（647~654 MPa）、抗拉强度高（811~831 MPa）、伸长率较小（15.0%~17.0%）。综合分析,采用缓冷工艺钢带的力学性能要优于空冷钢带的力学性能。

关键词: Ti-Nb-V微合金高强钢, 钢带, 卷取, 空冷工艺, 缓冷工艺, 组织, 力学性能