Effect of sulfate and dissolved hydrogen on oxide films on stainless steel in high-temperature water

Flow-Assisted Corrosion of Carbon Steel in Simulated Nuclear Plant Steam Generator Conditions

“…According to the published interpretation of the impedance spectra of construction materials in high-temperature water electrolytes [22][23][24][25][26][27], the process with the highest characteristic frequency is related to the electrical properties of the protective layer of oxide; that at intermediate frequencies, with ion Deconvolution of the impedance spectra indicates three processes with different characteristic frequencies in the phase angle curves. According to the published interpretation of the impedance spectra of construction materials in high-temperature water electrolytes [22][23][24][25][26][27], the process with the highest characteristic frequency is related to the electrical properties of the protective layer of oxide; that at intermediate frequencies, with ion and electron transfer at the oxide-coolant interface, and the low-frequency process is identified as the transport of point defects in the oxide. Spectra calculated using the model described in the Discussion section are shown with solid lines and demonstrate its ability to reproduce quantitatively both the magnitude and the frequency dependence of experimental spectra.…”

“…Deconvolution of the impedance spectra indicates three processes with different characteristic frequencies in the phase angle curves. According to the published interpretation of the impedance spectra of construction materials in high-temperature water electrolytes [22][23][24][25][26][27], the process with the highest characteristic frequency is related to the electrical properties of the protective layer of oxide; that at intermediate frequencies, with ion and electron transfer at the oxide-coolant interface, and the low-frequency process is identified as the transport of point defects in the oxide. Spectra calculated using the model described in the Discussion section are shown with solid lines and demonstrate its ability to reproduce quantitatively both the magnitude and the frequency dependence of experimental spectra.…”

“…The present model is based on the mixed-conduction model for oxide films (MCM), in analogy to previous estimates of the rates of oxidation and corrosion of low-alloyed and stainless steels in simulated primary and secondary coolants of nuclear power plants [22][23][24][25][26][27]. Assuming that the protective oxide on the studied steel is magnetite, the following processes take place at the alloy-oxide (A/O) and oxide-coolant (O/C) interfaces…”