某原油输送管道在停用充汽油期间于弯管环焊缝处发生穿孔泄漏失效，通过对管道环焊缝宏、微观形貌以及弯管运行工况进行分析，查明了其穿孔泄漏原因。结果表明：环焊缝发生穿孔的主要原因是环焊缝焊接时形成的未焊透缺陷，次要原因是管壁表面发生了腐蚀，穿孔后最终导致管道内的汽油发生泄漏。因此建议改进输油管道的焊接工艺，并加强焊缝质量检验。

Perforation and leakage failure occurred to a crude oil delivery pipeline full of gasoline at the elbow pipe girth weld position during outage. The macro and micro morphology of the elbow pipe girth weld and working conditions of the elbow pipe were analyzed to find out the reasons of the perforation leakage. The results show that the main reason was the incomplete penetration welding flaw and the minor reason was the corrosion occurring on the surface at the girth weld of the elbow pipe. Therefore, it was suggested that the pipeline welding technology should be improved and the weld quality inspection should be strengthened.