Due to water, sediment and chemical contaminants etc., the internal corrosion of subsea pipelines is inevitable. The internal corrosion is usually at or near the bottom of the subsea pipeline where the water and sediment can settle out of the transport medium. After some time, narrow and long defects occur in pipelines. Besides, as the temperature changes, the pipe is often stretched. Pipelines with long corrosion defect and axial tension subjected to high internal pressure have potential failure risk in service. In this paper, the effect of long corrosion defect and axial tension on the burst pressure of subsea pipelines are studied. Firstly, the pipelines with narrow and long corrosion defects are simplified as the Apollonius model. Then, a semi-empirical burst pressure equation of corroded pipelines subjected to internal pressure and axial tension is presented. Next, the accuracy of the burst pressure equation is verified by given experimental data. In the end, the effects of long corrosion defect and axial tension on burst pressure are analyzed. The results reveal that both axial tension and long corrosion defects can greatly reduce the burst pressure of pipelines. It is beneficial to assess the integrity of pipelines subjected high internal pressure and deepen the understanding of pipeline failure behavior.

由于水，沉积物和化学污染物等的影响，海底管道的内部腐蚀是不可避免的。内部腐蚀通常在海底管道的底部或附近，在那里水和沉积物可能从运输介质中沉降出来。一段时间后，管道中会出现狭窄和较长的缺陷。此外，随着温度的变化，管道经常被拉长。具有长期腐蚀缺陷和承受高内部压力的轴向张力的管道在使用中可能会导致故障。本文研究了长期腐蚀缺陷和轴向张力对海底管道爆破压力的影响。首先，将具有狭窄和长腐蚀缺陷的管道简化为Apollonius模型。然后，给出了腐蚀管道在内部压力和轴向张力作用下的半经验爆破压力方程。接下来，通过给定的实验数据验证了爆破压力方程的准确性。最后，分析了长期腐蚀缺陷和轴向张力对爆破压力的影响。结果表明，轴向张力和长期腐蚀缺陷均可大大降低管道的爆破压力。评估承受高内压的管道的完整性并加深对管道故障行为的了解是有益的。结果表明，轴向张力和长期腐蚀缺陷都可以大大降低管道的爆破压力。评估承受高内压的管道的完整性并加深对管道故障行为的了解是有益的。结果表明，轴向张力和长期腐蚀缺陷都可以大大降低管道的爆破压力。评估承受高内压的管道的完整性并加深对管道故障行为的了解是有益的。