相邻腐蚀缺陷管道剩余强度评价方法适应性研究

Study on the Adaptability of Residual Strength Evaluation Method for Adjacent Corroded Defective Pipelines

由于现行的腐蚀管道剩余强度评价方法均以单一腐蚀缺陷为研究对象,对相邻腐蚀之间的作用机理以及评价准则不明确,导致评价结果保守,造成管道过早更换或维修。针对这一问题,对改进的ASME B31G Modified、 ASME B31G—2009、 RSTRENG、 DNV-RP-F101和PCORRC准则等相邻腐蚀缺陷的评价方法进行了总结和梳理,通过对比水压爆破试验数据进行验证,可知将DNV-RP-F101的评价流程与PCORRC公式相结合可使评价结果更加准确,平均相对误差为4.54%;而RSTRENG有效面积法和ASME B31G Mo dified这两种评价准则没有考虑相邻腐蚀缺陷轴向和环向未腐蚀区域对剩余强度的贡献和影响,对相邻腐蚀缺陷的评价适应性不强。研究结果可为相邻腐蚀管道剩余强度的计算提供理论依据。

Because the existing residual strength evaluation methods of corroded pipelines all take a single corrosion defect as the research object,the mechanism of action between adjacent corrosion and the evaluation criteria are not clear,leading to the evaluation results are too conservative,resulting in premature replacement or maintenance of pipelines.In order to solve this problem,the evaluation methods of adjacent corrosion defects,such as ASME B31 G Modified criteria,ASME B31 G—2009,RSTRENG criterion,DNV RP-F101 criterion and PCORRC,are summarized and sorted out,and validated by calculating contrast test data of water pressure blasting.Results show that combining the evaluation process of DNV-RP-F101 with PCORRC formula can make the evaluation result more accurate,the average relative error is 4.54%.However,RSTRENG effective area method and ASME B31 G Modified criteria do not consider the contribution and influence of adjacent corrosion defects in axial and annular uncorroded areas to the residual strength,so the evaluation of adjacent corrosion defects is not adaptable.The research results can provide a theoretical basis for calculating the residual strength of adjacent corroded pipelines.