Corrosion production film of alloy 690 in high temperature and high pressure water containing Pb

Alloy 690 were put in autoclave to carry out corrosion test in high temperature and high pressure water containing Pb for 4400 h to study the corrosion film growth rule of alloy 690 in the solution containing Pb. The corrosion production film of alloy 690 in high temperature and high pressure water containing Pb was investigated by SEM, XRD, AES and Raman technique. The results show that the corrosion morphology is grain grid for the high corrosion rate of grain boundaries. The corrosion production film is the double layer, the outer layer is rich in Ni and the inner layer is rich in Cr. The corrosion production film is consisted of Cr₂O₃, NiFe₂O₄, NiO and other oxides. The new phase of Ni₂Cr is found in the passive film formed in Pb-containing solution. Pb in the surface corrosion product leads to the decrease of protectiveness of the passive film and increase of stress corrosion sensitivity.