X80M钢级长输管道环焊缝裂纹成因及适用性分析

Cause and Applicability Analysis of Girth Weld Crack in X80M Long Distance Transmission Pipeline

为研究某项目X80M钢级长输管道环焊缝裂纹成因及服役适用性,采用无损检测、水压物理模拟试验分析了含裂纹缺陷管道强度和裂纹扩展状况。通过裂纹解剖及金相分析确定了裂纹成因,采用含缺陷油气管道剩余强度评价方法对裂纹缺陷进行了评价。结果表明:水压物理模拟试验前后环焊缝裂纹尺寸无明显扩展,位置无变化,缺陷类型为环焊缝环向裂纹缺陷,裂纹成因为熔铜开裂,该类型裂纹缺陷均可接受,含该类型缺陷管道服役适用性良好。该研究结果对分析类似管道环焊缝裂纹成因及管道服役适用性具有一定参考价值。

In order to analyze the cause and safety applicability of the girth weld crack of X80M steel long⁃distance pipeline of a project.Nondestructive testing and hydraulic physical simulation test were used to analyze the strength and crack growth of the pipeline with cracks.The crack was dissected and metallographic analysis was performed to confirm the cause of the crack.The residual strength evaluation for oil and gas pipeline with defects was used to evaluate the crack defects.The results show that the crack size of the girth weld does not expand significantly and the position does not change before and after the hydraulic physical simulation test.The type of girth weld was girth crack defects,and the cause of the crack was copper melting cracking.This type of crack defect is acceptable,and the pipeline with this type of defect has good serviceability.It has reference value for analyzing the cracks causes in similar pipeline girth welds and the applicability of pipelines in service.