X80管线钢环焊缝力学性能及焊接缺陷分析

Analysis of Mechanical Property and Welding Defects of X80 Pipe Girth Weld

在X80管线钢环焊缝缺陷定期排查过程中,发现某处X80管道环焊缝存在多处缺陷。为了进一步确认缺陷类型并分析其产生原因,对环焊缝缺陷部位进行了解剖分析,并对环焊缝正常部位和缺陷部位的力学性能进行了检测。结果表明:该环焊缝0点钟位置的冲击韧性不满足标准要求,其他位置的力学性能满足标准要求;该环焊缝1:30时钟位置存在坡口未熔合,6:20时钟位置存在根部裂纹,坡口未熔合缺陷产生的原因为填充焊产生的焊渣未清理干净,根部裂纹产生的原因为环焊缝根焊部位应力过大导致开裂。

During the regular inspection of X80 pipe girth weld defects,a girth weld with several defects was found.In order to confirm the type of the defects and analyze the causes of the defects,the defective parts of girth weld were dissected and the mechanical properties of the girth weld were tested.The results show that the impact toughness of the girth weld at 0 o'clock does not conform to the requirements,the mechanical properties of other positions meet the requirements.Bedsides,there are two kinds of defects in the girth weld,one is groove incomplete fusion at 1:30,the other is root crack at 6:20.The cause of groove incomplete fusion is that the slag inclusion produced during filler welding is not cleaned up.The reason of root crack is the cracking caused by excessive stress in root welding of girth weld.