Development of Corrosion Fatigue Testing System in Marine Environment for WELded Structural Components and Establishment of Design Standard for Corrosion Fatigue

为了建立腐蚀疲劳设计标准，对HT60钢对接焊接接头进行了海洋环境下腐蚀疲劳裂纹扩展试验。母材在空气中的疲劳裂纹扩展速率几乎不受应力比的影响。而海洋环境中腐蚀疲劳裂纹扩展速率与应力比有显著关系。焊接接头的腐蚀疲劳裂纹扩展速率小于母材，且随应力比的减小而减小。这种腐蚀疲劳行为是由焊接残余应力和钙质堆积物的楔入效应共同作用的结果。

In the present study, a corrosion fatigue crack propagation testing under tghe marine environment was carried out for butt welded joints of HT60 steel in order to establish the design standard for corrosion fa- tigue. The fatigue crack propagation rate of base metal in air showed scarecely the depandence on stress ratio. Hile the corrosion fatigue crack propagation rate in marine environment depended remarkably on the stress ratio. The corrosion fatigue crak propagation rate was smaller for welded joint than for base metal, and decreased with decreasing the stress ratio. Such crrosion fatigue behavior resulted from the welding residual stress and the wedging effect bu calcareous deposits.