对Q345B钢淬火后在450℃进行60 min传统回火和不同温度、不同时间的感应回火处理后空冷,并进行组织观察、硬度测试和夏比V型坡口低温冲击试验。结果表明:Q345B钢感应回火后显微组织更加细小,硬度高于传统回火的5%~20%,而感应回火的低温韧性略差于传统回火。 The Q345B steel was tempered at 450 ℃ for 60 min and tempered at different temperatures for different periods of time. The Q345B steel was air-cooled and then subjected to microstructure observation, hardness test and Charpy V-groove low temperature impact test. The results show that the microstructure of Q345B steel after induction tempering is finer and the hardness is 5% ~ 20% higher than that of the traditional tempering. However, the low temperature toughness of induction tempering is slightly worse than the traditional tempering.