16Mn钢油气集输管线弯管失效分析

Failure analysis on 16Mn steel elbow for oil and gas gather-transport pipeline

用金相显微镜、扫描电镜和X射线衍射分析方法对油气井集输用16Mn钢弯管失效件的显微组织、宏观形貌和产物组成进行了分析。结果表明,输送介质中的CO2腐蚀引起弯管内壁变形处出现腐蚀坑,并在输送压力和油、气、固多相流的冲刷作用下使弯管顶端内表面产生应力腐蚀,从而导致弯管发生破裂。

The microstructure,corrosion morphology and products of failure 16Mn steel elbow for oil and gas gather-transport pipeline were investigated by use of metallographic microcopy,scanning electron microscope and X-ray diffraction methods.The results show that,the CO2 in transport media induces corrosion pits in the deformation area of inner wall of the elbow,together with the transport pressure and the oil-gas-solid multi phase flow erosion,results in stress corrosion cracking existing in the internal surface of top area of elbow,leading to the breakdown and failure of the pipe elbow.