摘要
某304L不锈钢疏水管焊接接头处发生开裂失效。利用金相显微镜、扫描电镜、能谱仪,X射线衍射仪等对失效管道进行了分析;并用Ansys软件模拟分析了管内流体流速对管道受力情况的影响。结果表明:两疏水管道的失效形式均为腐蚀疲劳开裂,裂纹均在焊接接头的焊趾处萌生,且均为多源开裂;水流经过时,焊接接头附近形成负压区,导致该部位多处发生空泡腐蚀;空泡腐蚀产生的腐蚀坑处应力集中,成为疲劳裂纹源;空泡爆破时产生的巨大冲击应力造成管道振动,引发腐蚀疲劳破裂。
Cracking failure occurred at the welded joints of two 304L stainless steel drain pipes.The failed pipes were investigated by metallographic microscopy,scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD).And Ansys software was used to simulate and analyze the influence of fluid rate on the stress distribution in the pipes.The results show that the failure modes of the two drain pipes were corrosion fatigue cracking.All cracks were initiated at the weld toes of the welded joints with several crack sources.When water flew,a negative pressure area was formed near the welded joint,leading to cavitation corrosion at many places in the area.Corrosion pits generated by cavitation corrosion were the stress concentration points and became sources of fatigue cracks.The tremendous impact stress caused by cavitation blasting could induce pipe vibration,which finally led to corrosion fatigue cracking.
作者
边春华
张维
刘洪群
王云伟
文杰
BIAN Chunhua;ZHANG Wei;LIU Hongqun;WANG Yunwei;WEN Jie(CNNC Nuclear Power Operations Management Co.,Ltd.,Haiyan 314300,China;Suzhou Nuclear Power Research Institute, Suzhou 215004,China)
出处
《腐蚀与防护》
CAS
北大核心
2019年第8期608-613,共6页
Corrosion & Protection
关键词
焊接接头
不锈钢
腐蚀疲劳
空泡腐蚀
welded joint
stainless steel
corrosion fatigue
cavitation corrosion
