腐蚀缺陷对中高强度油气管道失效压力的影响

腐蚀管道评价规范ASME-B31G、BS7910、DNV-RP-F101、PCORRC大多以X60以下中低强度管道为研究对象，对X60以上中高强度油气管道的评价具有一定的保守性。笔者以X65和X80两种中高强度管材为研究对象，采用非线性有限元法分析了带腐蚀缺陷油气管道的失效压力，研究了腐蚀缺陷深度、腐蚀缺陷长度、腐蚀缺陷宽度和腐蚀缺陷位置对带腐蚀缺陷油气管道失效压力的影响，建立了包含腐蚀缺陷深度、腐蚀缺陷长度、腐蚀缺陷位置等参数的带腐蚀缺陷油气管道失效压力计算方法。与现有标准提供的计算方法和试验结果对比表明：本文拟合得到的计算方法误差小，保守性低，可以满足X60以上中高强度腐蚀管道失效压力的预测要求。

Impact of corrosion defects on failure pressure of medium-high strength oil-gas pipelines

Evaluation standards for corrosion defects of pipelines, such as ASME-B31G, BS7910, DNV-RP-F101 and PCORRC, are mostly applicable to low-strength pipelines under X60, but, to some extent, conservative to medium-high strength oil-gas pipelines of over X60. We took X65 and X80 pipelines as study objects to analyze failure pressure of oil-gas pipelines with corrosion defects using a nonlinear finite element method, in which effects of different corrosion defects, including depth, length, width and location of corrosion defects, on failure pressure of oil-gas pipelines were examined in detail. A method to calculate failure pressure of oil-gas pipelines with various corrosion defects mentioned above was then established. Compared with existing calculation methods available with current evaluation standards, the calculation method fitted by the present paper shows a much more satisfactory precision and can meet the requirement to predict failure pressure of the over X60, medium-high strength corroded pipelines.