摘要
对埋弧焊管检验中出现的正弯和反弯不合格试样进行了金相分析,发现这些不合格试样均在焊缝焊趾处存在微裂纹或微咬边,这是导致弯曲开裂的主要原因。产生微裂纹的原因是焊缝与母材过渡不平滑,焊趾处应力集中过大,再加上矫平试样时未去除焊缝余高;产生微咬边的原因是焊接过程中焊接规范不恰当或焊接过程设备运行不稳定。
Metallographic test analysis was carried out for unqualified face bend and reverse bend samples during submerged arc welded pipe production,the results indicated that the main reason caused bending cracking is micro-crack or micro-undercut existd at the weld toe.The reason caused micro-crack is weld and base metal transition is not smooth,stress concentration is too large at weld toe,and during leveling of specimen does not remove weld reinforcement.Welding specification is not appropriate or welding equipments are not stable during welding process caused mocro-undercut.
出处
《焊管》
2010年第6期58-59,共2页
Welded Pipe and Tube
关键词
埋弧焊管
正弯
反弯
微裂纹
微咬边
submerged arc welded pipe
face bend
reverse bend
micro-crack micro-undercut
