THE INFLUENCE OF ZRO ZRO2 TREATMENT ON THEELECTROCHEMICAL BEHAVIOR OF OXYGEN ANDHYDROGEN ON TYPE 304 STAINLESS STEELS IN HIGHTEMPERATURE WATER

摘要

For enhancing the effectiveness of hydrogen water chemistry (HWC) in boiling water reactors (BWRs) the aspects of lower hydrogen consumption and of a more effective reduction in electrochemicalrncorrosion potential (ECP), the technique of inhibitive protective coating on structural materials wasrnbrought into consideration. In the current study, electrochemical polarization analyses at 288 ℃ werernconducted to characterize the electrochemical properties of ZrO2 treated and untreated 304 stainless steelrnspecimens in pure water with dissolved oxygen or hydrogen. The polarization results showed that therntreated specimens exhibited lower corrosion potentials, corrosion current densities, exchange currentrndensities, and cathodic current densities than the untreated one in high temperature pure water withrndissolved oxygen. For the environment with dissolved hydrogen only, reductions in anodic current densityrnand exchange current density were observed, indicating that the ZrO2 treatment also deterred thernoxidation reaction of hydrogen. However, in comparison with the data obtained, the ZrO2 treatmentrnseemed to be relatively more effective in inhibiting the oxygen reduction reaction than inhibiting thernhydrogen oxidation reaction.