Inhibition Effects of Low Concentration of Boron on Corrosion of Zirconium Alloy

The high temperature electrochemical corrosion behavior of zirconium alloy was studied by potential dynamic polarization and electrochemical impedance spectrogram (EIS) under three normal boron-lithium water chemistry conditions with the same pH and the uniform corrosion behavior of zirconium alloy was investigated by weight gain and microanalysis under two lithium-concentrated water chemistry conditions. The high temperature electrochemical corrosion tests indicate that the increase of boron concentration can reduce the passive current density and increase the electrochemical impedance value of zirconium alloy under three normal boron-lithium water chemistry conditions despite of the same pH, consequently the boron is beneficial to corrosion inhibition of zirconium alloy. The uniform corrosion tests show that adding boron can obviously decrease the corrosion weight gain, oxide film thickness and compact the oxide films by contrast to the lithium-concentrated water chemistry condition without boron, thus the boron is beneficial to improve the corrosion resistance of zirconium alloy under lithium concentrated water chemistry conditions. (authors)