Investigation via Electron Microscopy and Electrochemical Impedance Spectroscopy of the Effect of Aqueous Zinc Ions on Passivity and the Surface Films of Alloy 600 in PWR PW at 320 °C
Aqueous zinc ions lower the corrosion rate of Alloy 600, which helps lower the radiation dose rate in pressurized water reactors (PWRs). The influence of zinc on the electrochemical behavior of Alloy 600 in PWR primary water (PW) at 320 °C was investigated using a combination of electron microscopy...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-01-01
|
| Series: | Corrosion and Materials Degradation |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2624-5558/4/1/5 |
| _version_ | 1797612571532984320 |
|---|---|
| author | Yifan Jiang Karen C. Bustillo Thomas M. Devine |
| author_facet | Yifan Jiang Karen C. Bustillo Thomas M. Devine |
| author_sort | Yifan Jiang |
| collection | DOAJ |
| description | Aqueous zinc ions lower the corrosion rate of Alloy 600, which helps lower the radiation dose rate in pressurized water reactors (PWRs). The influence of zinc on the electrochemical behavior of Alloy 600 in PWR primary water (PW) at 320 °C was investigated using a combination of electron microscopy and electrochemical impedance spectroscopy (EIS). Secondary electron microscopy (SEM) and scanning transmission electron microscopy (STEM)/energy-dispersive X-ray spectroscopy (EDS) indicated duplex surface films were formed on the Alloy 600 in PWR PW with and without 100 ppb of zinc. There was no effect of zinc on the chromium-rich inner layer (IL) (of Cr<sub>2</sub>O<sub>3</sub> and/or CrOOH). Zinc had a significant effect on the outer layer (OL). In the absence of zinc, a highly porous OL formed that was mostly composed of nickel oxide whiskers. In the presence of zinc, a zinc-containing, denser OL of oxide was formed. The EIS data were acquired in laboratory simulated PWR PW at 320 °C with and without 100 ppb zinc. The spectra were measured at nine different values of potential that spanned a 500 mV-wide range. The EIS indicated there was no effect of zinc on the oxidation rate of metals at the alloy/IL interface nor on the transport of ions through the IL. Zinc lowered the corrosion rate because the dense OL inhibited the release of nickel ions from the IL into the solution. |
| first_indexed | 2024-03-11T06:43:59Z |
| format | Article |
| id | doaj.art-a551e99ffdb245bfa88d6d81daedf4ac |
| institution | Directory Open Access Journal |
| issn | 2624-5558 |
| language | English |
| last_indexed | 2024-03-11T06:43:59Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Corrosion and Materials Degradation |
| spelling | doaj.art-a551e99ffdb245bfa88d6d81daedf4ac2023-11-17T10:24:37ZengMDPI AGCorrosion and Materials Degradation2624-55582023-01-0141548910.3390/cmd4010005Investigation via Electron Microscopy and Electrochemical Impedance Spectroscopy of the Effect of Aqueous Zinc Ions on Passivity and the Surface Films of Alloy 600 in PWR PW at 320 °CYifan Jiang0Karen C. Bustillo1Thomas M. Devine2Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USANational Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USADepartment of Materials Science and Engineering, University of California, Berkeley, CA 94720, USAAqueous zinc ions lower the corrosion rate of Alloy 600, which helps lower the radiation dose rate in pressurized water reactors (PWRs). The influence of zinc on the electrochemical behavior of Alloy 600 in PWR primary water (PW) at 320 °C was investigated using a combination of electron microscopy and electrochemical impedance spectroscopy (EIS). Secondary electron microscopy (SEM) and scanning transmission electron microscopy (STEM)/energy-dispersive X-ray spectroscopy (EDS) indicated duplex surface films were formed on the Alloy 600 in PWR PW with and without 100 ppb of zinc. There was no effect of zinc on the chromium-rich inner layer (IL) (of Cr<sub>2</sub>O<sub>3</sub> and/or CrOOH). Zinc had a significant effect on the outer layer (OL). In the absence of zinc, a highly porous OL formed that was mostly composed of nickel oxide whiskers. In the presence of zinc, a zinc-containing, denser OL of oxide was formed. The EIS data were acquired in laboratory simulated PWR PW at 320 °C with and without 100 ppb zinc. The spectra were measured at nine different values of potential that spanned a 500 mV-wide range. The EIS indicated there was no effect of zinc on the oxidation rate of metals at the alloy/IL interface nor on the transport of ions through the IL. Zinc lowered the corrosion rate because the dense OL inhibited the release of nickel ions from the IL into the solution.https://www.mdpi.com/2624-5558/4/1/5passive filmAlloy 600pressurized water reactor primary water with zincelectrochemical impedance spectroscopyscanning transmission electron microcopyenergy-dispersive spectroscopy |
| spellingShingle | Yifan Jiang Karen C. Bustillo Thomas M. Devine Investigation via Electron Microscopy and Electrochemical Impedance Spectroscopy of the Effect of Aqueous Zinc Ions on Passivity and the Surface Films of Alloy 600 in PWR PW at 320 °C Corrosion and Materials Degradation passive film Alloy 600 pressurized water reactor primary water with zinc electrochemical impedance spectroscopy scanning transmission electron microcopy energy-dispersive spectroscopy |
| title | Investigation via Electron Microscopy and Electrochemical Impedance Spectroscopy of the Effect of Aqueous Zinc Ions on Passivity and the Surface Films of Alloy 600 in PWR PW at 320 °C |
| title_full | Investigation via Electron Microscopy and Electrochemical Impedance Spectroscopy of the Effect of Aqueous Zinc Ions on Passivity and the Surface Films of Alloy 600 in PWR PW at 320 °C |
| title_fullStr | Investigation via Electron Microscopy and Electrochemical Impedance Spectroscopy of the Effect of Aqueous Zinc Ions on Passivity and the Surface Films of Alloy 600 in PWR PW at 320 °C |
| title_full_unstemmed | Investigation via Electron Microscopy and Electrochemical Impedance Spectroscopy of the Effect of Aqueous Zinc Ions on Passivity and the Surface Films of Alloy 600 in PWR PW at 320 °C |
| title_short | Investigation via Electron Microscopy and Electrochemical Impedance Spectroscopy of the Effect of Aqueous Zinc Ions on Passivity and the Surface Films of Alloy 600 in PWR PW at 320 °C |
| title_sort | investigation via electron microscopy and electrochemical impedance spectroscopy of the effect of aqueous zinc ions on passivity and the surface films of alloy 600 in pwr pw at 320 °c |
| topic | passive film Alloy 600 pressurized water reactor primary water with zinc electrochemical impedance spectroscopy scanning transmission electron microcopy energy-dispersive spectroscopy |
| url | https://www.mdpi.com/2624-5558/4/1/5 |
| work_keys_str_mv | AT yifanjiang investigationviaelectronmicroscopyandelectrochemicalimpedancespectroscopyoftheeffectofaqueouszincionsonpassivityandthesurfacefilmsofalloy600inpwrpwat320c AT karencbustillo investigationviaelectronmicroscopyandelectrochemicalimpedancespectroscopyoftheeffectofaqueouszincionsonpassivityandthesurfacefilmsofalloy600inpwrpwat320c AT thomasmdevine investigationviaelectronmicroscopyandelectrochemicalimpedancespectroscopyoftheeffectofaqueouszincionsonpassivityandthesurfacefilmsofalloy600inpwrpwat320c |