Susceptibility to intergranular corrosion of Super 304H stainless steel welded joint

The susceptibility to intergranular corrosion for weld and base metal of Super 304H steel was investigated by double loop electrochemical potentiodynamic(EPR).The experimental results indicate that the weld and base metal have the lower tendency of intergranaular corrosion.The mircrostructure of weld and base metal was investigated by means of scanning electron microscopy,electron probe micro-analysis,X-ray diffraction and transmission electron microscope.The results showed that both the weld and the base metal were consisted of γ-matrix and some precipitated phase,no obvious Cr₂₃C₆ was detected.Therefore,no chromium depleted zone was formed.However,the susceptibility to intergranular corrosion of weld is better than that of base metal due to the difference of alloy elements.