B31.G腐蚀管道剩余强度评价比较分析

Evaluation on Residual Strength of Corroded B31.G Pipeline

油气长输管道的腐蚀剩余强度评价一直是管道完整性管理的重要内容,国外在腐蚀管道的剩余强度评价方面已取得很大成就。详细说明了ASME B31.G管道腐蚀剩余强度评价方法及其各种改进方法,对其优缺点和保守性进行了分析,通过选取不同的腐蚀面积计算公式、膨胀系数计算公式,不同的流变应力进行计算,结果表明,膨胀系数M的选择对失效压力的影响很小;腐蚀面积计算方法的选择对失效压力的影响很大;不同的流动应力定义会得到不同的评价结果,相对于不同的膨胀系数M和不同的面积计算方法而言,不同的流动应力选择对评价结果的影响更大。

The evaluation of residual strength of corroded long-distance oil and gas pipelines has long been an important part of pipeline integrity management and great achievement in evaluation of residual strength has been obtained in foreign countries.Described in detail are methods of evaluating residual strength of corroded pipelines in ASME B31.G and other improvement methods,analyzed are advantages and disadvantages of such methods and their conservatism,selected are various computational formulas used for corrosive area and expansion coefficient to calculate different flow stresses and computed results show that selection of expansion coefficient M has little effect on failure pressure,selection of calculation methods used for corrosive area has great effect on failure pressure,different definitions of flow stress will result in different evaluation also and selection of different flow stresses will have greater effect on evaluation results than selection of expansion coefficient M and corrosive area calculation methods.