埋地管道断裂失效分析与剩余寿命预测

Fracture Failure Analysis and Residual Life Prediction of Buried Pipeline

某段埋地管道发生断裂泄漏。通过对管道断口宏观和微观观察、材料化学成分分析、显微组织观察、力学性能试验和应力分析,找出了管道断裂失效的原因,并对管道进行修复后剩余寿命预测。分析结果表明:由于管道存在焊接缺陷,导致埋地管道焊缝的有效承载面积降低,当地面沉降或路面载荷高于管道焊缝的承载能力时,管道焊缝处发生脆性断裂。在只考虑管道内压对管道的影响时,管道均匀腐蚀缺陷通过一级评价,在未来5年的使用周期内可以满足工况要求。建议改进管道的焊接工艺,严格控制沉降和外载荷突出部位的管道焊接质量,严格控制未焊透、气孔等焊接缺陷,并加强管道在实际运行中的监测,做好预警措施。

A section of buried pipeline breaks and leaks.Through macroscopic and microscopic observation of pipeline fracture,material chemical composition analysis,microstructure observation,mechanical property test and stress analysis,the causes of pipeline fracture failure were found out and the remaining life of repaired pipeline was predicted.The analysis results show that the effective bearing area of the welded joint of buried pipeline decreases due to welding defects of pipeline.When the ground settlement or road load is higher than the bearing capacity of the welded joint of pipeline,brittle fracture occurs at the welded joint of pipeline.Only considering the influence of the internal pressure of pipeline on the pipeline,the uniform corrosion defect of pipeline can meet the working condition requirements in the next 5 years,which meets the first level evaluation.It is suggested to improve the welding process of the pipeline,strictly control the welding quality of the pipeline where the settlement and external load are prominent,strictly control the welding defects such as incomplete penetration and porosity,strengthen the monitoring of the pipeline in actual operation,and take early warning measures.