X70级φ1016 mm×17.5 mm天然气管道环焊缝缺陷剖析

摘要

针对某天然气管道工程用X70级φ1 016 mm×17.5 mm焊管环焊缝焊接接头出现的缺陷,应用超声波检测和射线检测方法对缺陷进行了定位和定量检测,并通过金相分析、扫描电镜分析了缺陷中材料的性质.分析结果表明,此缺陷为第一次焊接过程中产生的焊渣在第二次补焊时未清理干净而产生的坡口未熔合.同时,分析了由于射线检测透照角度不同造成的射线底片影像异常现象.最后给出了焊接和无损检测过程中的一些合理化建议.%In this paper,aimed at the defects appeared in circumferential weld of X70 φ 1 016 mm×17.5 mm welded joint in some gas pipeline project,the positioning and quantitative detection for defects were carried out by ultrasonic inspection and X-ray inspection,and the material properties of defects were analyzed through metallographic analysis and SEM.The results showed that this kind of defect is incomplete fusion groove,which occurred in the first welding pass and didn't be cleaned completely after the second repair welding.At the same time,the abnormal phenomena of X-ray radiograph caused by different transillumination angle.Finally,some reasonable proposals in the process of welding and non-destructive test were put forward.