在Gleeble3800热模拟试验机上,测定了HQ100热轧高强钢的动态CCT曲线,并通过光学显微镜和透射电镜观察试验钢在不同冷却条件下的显微组织形貌,以及采用显微硬度法检测其维氏硬度。结果表明:在0.1~60℃/s冷速范围内,试验钢存在珠光体、贝氏体、马氏体转变区;随着冷速的增加,试验钢硬度增加;冷速高于10℃/s时,试验钢屈服强度达到900 MPa以上,满足高强度工程机械用钢的要求;组织中存在大量50nm以下含Ti、V、Mo元素的析出相粒子,其强化机理以沉淀强化和相变强化为主。 On the Gleeble3800 thermal simulator, the dynamic CCT curves of HQ100 hot rolled high strength steel were measured. The microstructure and microstructure of the test steel under different cooling conditions were observed by light microscope and transmission electron microscope. Hardness. The results show that there exists pearlite, bainite and martensite transformation zone in the range of 0.1 ~ 60 ℃ / s cooling rate. With the increase of cooling rate, the hardness of test steel increases. When the cooling rate is higher than 10 ℃ / s, the yield strength of the test steel reaches more than 900 MPa, which meets the requirements of high strength steel for construction machinery. There are a large number of precipitated particles with Ti, V and Mo below 50 nm in the microstructure. The strengthening mechanism is precipitation strengthening and phase transformation strengthening Mainly.