奥氏体不锈钢焊条焊接Cr5Mo工艺管线接头长期高温服役前后熔合区的组织和性能

Microstructure and Mechanical Properties of Cr5Mo Pipe Joints Welded with Austenitic Stainless Steel Electrode Before and After Long Term Service at High Temperature

本文对用奥氏体不锈钢焊条焊接的新旧Cr5Mo管线接头进行了试验研究,结果表明,在旧接头熔合区发生了碳从Cr5Mo钢管一侧向焊缝金属一侧的迁移。因此,在500℃运行了14万小时的焊缝熔合区的室温冲击韧性和断裂韧性比新接头低得多,但在400℃以上时,旧接头熔合区的冲击功与新接头大致相同。

The new and old Cr5Mo pipe joints welded with austenitic stainless steel electrode are investigated experimently. Test results show that carbon transfer from Cr5Mo to weld metal has taken place in the fusion zone of the old joint. There is a hard carbide layer, 0.05mm in thickness, in the fusion zone on the weld metal side, therefore, the notch toughness and fracture toughness at room temperature in this zone of the weld joint which has served at 500℃ for over 14 thousand hours are much lower than that of new joint. At the temperature of over 400℃, however, its notch toughness is almost as high as that of the new one.