Electrochemical Behavior of Platinum Treated Type 304 Stainless Steels in Simulated BWR Environments Under Startup Conditions
As reactor startup begins, the ECP is initially high in the oxygenated water environment established during a cold shutdown. Consequently, the components would exhibit the higher crack initiation and propagation rates of IGSCC during startup period than in the remainder of the cycle. The corrosion current density response of stainless steel exposed to H2O2 was larger than that of those exposed to O2, and it remained at a higher value even at the low level of several ppb. As noble metal was applied in the BWRs to catalyze the chemical reactions of H2O2 and O2, this study evaluated the corrosion behaviors of both oxidants on the components of stainless steel. The corrosion potentials and corrosion current densities of 304SS with Pt coating were investigated in pure water with dissolved oxygen or hydrogen peroxide concentrations at various temperatures.
KeywordsStress corrosion cracking Reactor startup 304 stainless steel Pt Normal water chemistry
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