10Ni8CrMoV钢热影响区粗晶区在二次焊接热循环中的组织转变与韧性

Microstructure Transformation and Toughness of Coarse Grain Heat Affect Zone of 10Ni8CrMoV Steel During Second Welding Thermal Cycle

采用焊接热模拟试验及金相、透射电镜分析技术研究了10Ni8CrMoV钢一次热循环的粗晶区在二次热循环过程中的组织转变与韧性特征,结果表明:由于马氏体板条间奥氏体薄膜的存在,10Ni8CrMoV钢在二次热循环作用下仍具有良好的低温冲击韧度,再热粗晶区、临界再热粗晶区均未出现局部脆化现象。但试验钢临界再热粗晶区因发生组织遗传,其低温冲击韧度相对于一次热循环粗晶区稍有降低。

After welding second thermal cycle,the microstructure and toughness of coarse-grained heat-affected zone（CGHAZ） of 10Ni8CrMoV steel were investigated by using welding thermal simulation experiment ,metallographic analysis and TEM. The results show that the experiment steel maintains excellent impact toughness at low temperature during second welding thermal cycle because of the exist of anstenite film between lath martensites. But the impact toughness of the intercritically reheated CGHAZ at low temperature decreases slightly owing to the microstructural inheritance.