电站凝汽器钛管断裂原因分析

Fracture Analysis of Titanium Tube in Power Station Condenser

电站在进行汽轮机试验时一根凝汽器钛管发生断裂。通过采取表面宏观检查、断口分析、材质检查等方法,对钛管断裂原因进行分析,并提出改进方案。结果表明:钛管的断裂性质为高周疲劳断裂,疲劳源位于钛管的焊缝位置;钛管断裂与蒸汽冲刷导致钛管振幅过大有关,从而在疲劳性能相对较差的焊缝处萌生裂纹源。通过增加防冲板的方式,可以有效避免类似故障。

A titanium tube of condenser in power station fractured during steam turbine test.In order to find out the fracture mode and cause,macro examination,SEM analysis and material examination were carried out.The test results show that the fracture mode was high-cycle fatigue fracture,and the crack initiated from the weld of the titanium tube.The fracture of the titanium tube was related to the excessive amplitude caused by steam impact.Similar failures can be effectively avoided by installing the protection plate.