Corrosion behavior of 304L stainless steel in a B-Li coolant for a nuclear power plant

The corrosion behavior of 304L stainless steel (SS) in B/Li solutions with different concentrations was studied by means of X-ray diffraction (XRD), scanning electron microscope (SEM), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurement.The results showed that the oxide film formed at high temperature and a high pressure water is mainly composed of magnetite and the oxide film formed in a 1000 mg/L B and 2.2 mg/L Li solution is thicker than that in a 2000 mg/L B and 3.5 mg/L Li solution.The outer surface oxide particles' size and inner film uniformity is affected by the B/Li concentration.The pitting potential and the modulus of impedance of the 304L in 1000 mg/L B and 2.2 mg/L Li solutions were higher than the 2000 mg/L B and 3.5 mg/L Li solutions.The solution of 1000 mg/L B and 2.2 mg/L Li is beneficial for the corrosion resistance, because of forming a stable oxide film on the 304L surface.