断裂力学法在油气管道腐蚀评价中的应用研究

Application study of fracture mechanic method on oil and gas pipeline corrosion evaluation

为节省油气管道维修费用,预防油气泄漏事故,以均匀腐蚀油气管道为研究对象,建立管道剩余强度评价模型。管道均匀腐蚀发生后,应用弹塑性断裂力学法寻求断裂准则,深入分析环向和轴向应力,建立评价模型,判断缺陷可接受程度,若不可接受,则以管道最大允许工作压力值反映均匀腐蚀缺陷管道的承压能力。实证分析表明,管道外径与最大允许工作压力呈负相关关系,最小测量壁厚和屈服强度与其呈正相关关系。这些结果与实际情况较为吻合。

In order to reduce oil and gas pipeline maintenance costs, prevent oil and gas leakage accidents, taking oil and gas pipeline suffuring from uniform corrosion as the research object, for which a residual strength evaluation model was built. An elastic plastic fracture mechanics method was used to establish a fracture criterion for uniformly corroded pipeline and further analyse the ring and axial stress. An evaluation model was built for judging the acceptability of flaws. If not accepted, the maximum allowable working pressure value was used to reflect the bearing capacity of pipelines suffuring from uniform corrosion and defects. The empirical analysis showed that there is a negative correlation between the pipe diameter and maximum allowable working pressure, and there is a positive correlation between the maximum allowable working pressure and both minimum measuring wall thickness and yield strength. These results conform to the facts.