Q370R微合金钢的连续冷却转变行为

Continuous Cooling Transformation Behavior of Q370R Steel

利用MMS-200热模拟试验机和C-STRAIN传感器,结合显微组织的观察与分析,对压力容器用Q370R微合金钢的静态连续冷却转变行为进行了研究,并分析了热变形对相变组织的影响。试验结果表明:冷却速率较低时, Q370R微合金钢的相变组织为铁素体+珠光体,冷速为5℃/s时,主要为铁素体+珠光体+少量贝氏体的相变组织,冷速≥10℃/s时,铁素体和珠光体迅速变少,相变组织主要以贝氏体为主,并逐渐有马氏体的产生。相同冷速下,热变形与未变形的相变组织在低冷速下存在差异,而当冷速≥5℃/S时,两者组织无明显差异。试验测得Q370R微合金钢的相变开始温度Ac1和Ac3分别为744℃和865℃。

By using MMS-200thermo-mechanical simulator and C-STRAIN dilatometer in combination with microstructure observation and analysis,the static continuous cooling transformation (CCT)behaviors of Q370R steel for pressure vessels were investigated,and the effect of hot deformation on phase transformation was show that the microstructure is consisted of ferrite and rate is ≥10℃/s,bainite and martensite can be also analyzed in this experiment.The results pearlite at low cooling rate.When the cooling obtained when increasing the cooling rate successively.When the cooling rates are the same,the micro-structure of hot deformed and nondeformed in continuous cooling transformation are different at low cooling rate,but there is no obvious difference when the cooling rate is ≥5℃/S.Phase transformation temperature is obtained in this experiment which shows that A cl Ac3is 744℃and 865℃ respectively.