Corrosion of carbon steel and the passivating properties of corrosion films formed under high-PT geothermal conditions
Abstract
Corrosion is a major obstacle to a safe implementation of geotechnical applications. Here, using a novel approach that includes vertical scanning interferometry (VSI) and electrochemical impedance spectroscopy (EIS) we discuss time-dependent carbon steel corrosion and film formation at geothermally relevant temperatures (80-160 °C) in CO2-saturated mildly acidic Na—Cl brine. Iron dissolution kinetics follows a logarithmic rate at 80 and 160 °C and a linear rate at 120 °C. At 80 °C, high initial corrosion rates (first 24 h) generate H2 at a minimum rate of 12 μmol h-1 cm-2 and lead to the formation of a continuous ~100 μm thick porous corrosion film. It exhibits a duplex structure with a crystalline outer FeCO3 layer and an inner layer composed of a skeletal network of Fe3C impregnated with FeCO3. Being an electrical conductor we hypothesize the Fe3C to strongly enhance corrosion rates by providing additional cathodic sites. Pseudo-passivity due to an anodic film-forming reaction (presumably Fe-oxide) was observed at 120 and 160 °C, soon followed by the initiation of pitting at 120 °C. Steady-state corrosion rates at 160 °C are at least one order of magnitude lower than for 120 °C. Lastly, our experimental approach demonstrated potential for general applicability inmore »
- Authors:
-
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Univ. of California, Berkeley, CA (United States)
- Friedrich Schiller Univ., Jena (Germany)
- Publication Date:
- Research Org.:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1528904
- Grant/Contract Number:
- AC02-05CH11231
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Science of the Total Environment
- Additional Journal Information:
- Journal Volume: 677; Journal Issue: C; Journal ID: ISSN 0048-9697
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 58 GEOSCIENCES; 36 MATERIALS SCIENCE
Citation Formats
Mundhenk, Niklas, Knauss, Kevin G., Bandaru, Siva R. S., Wonneberger, Robert, and Devine, Thomas M. Corrosion of carbon steel and the passivating properties of corrosion films formed under high-PT geothermal conditions. United States: N. p., 2019.
Web. doi:10.1016/j.scitotenv.2019.04.386.
Mundhenk, Niklas, Knauss, Kevin G., Bandaru, Siva R. S., Wonneberger, Robert, & Devine, Thomas M. Corrosion of carbon steel and the passivating properties of corrosion films formed under high-PT geothermal conditions. United States. https://doi.org/10.1016/j.scitotenv.2019.04.386
Mundhenk, Niklas, Knauss, Kevin G., Bandaru, Siva R. S., Wonneberger, Robert, and Devine, Thomas M. Sat .
"Corrosion of carbon steel and the passivating properties of corrosion films formed under high-PT geothermal conditions". United States. https://doi.org/10.1016/j.scitotenv.2019.04.386. https://www.osti.gov/servlets/purl/1528904.
@article{osti_1528904,
title = {Corrosion of carbon steel and the passivating properties of corrosion films formed under high-PT geothermal conditions},
author = {Mundhenk, Niklas and Knauss, Kevin G. and Bandaru, Siva R. S. and Wonneberger, Robert and Devine, Thomas M.},
abstractNote = {Corrosion is a major obstacle to a safe implementation of geotechnical applications. Here, using a novel approach that includes vertical scanning interferometry (VSI) and electrochemical impedance spectroscopy (EIS) we discuss time-dependent carbon steel corrosion and film formation at geothermally relevant temperatures (80-160 °C) in CO2-saturated mildly acidic Na—Cl brine. Iron dissolution kinetics follows a logarithmic rate at 80 and 160 °C and a linear rate at 120 °C. At 80 °C, high initial corrosion rates (first 24 h) generate H2 at a minimum rate of 12 μmol h-1 cm-2 and lead to the formation of a continuous ~100 μm thick porous corrosion film. It exhibits a duplex structure with a crystalline outer FeCO3 layer and an inner layer composed of a skeletal network of Fe3C impregnated with FeCO3. Being an electrical conductor we hypothesize the Fe3C to strongly enhance corrosion rates by providing additional cathodic sites. Pseudo-passivity due to an anodic film-forming reaction (presumably Fe-oxide) was observed at 120 and 160 °C, soon followed by the initiation of pitting at 120 °C. Steady-state corrosion rates at 160 °C are at least one order of magnitude lower than for 120 °C. Lastly, our experimental approach demonstrated potential for general applicability in studying corrosion-related phenomena.},
doi = {10.1016/j.scitotenv.2019.04.386},
journal = {Science of the Total Environment},
number = C,
volume = 677,
place = {United States},
year = {Sat Apr 27 00:00:00 EDT 2019},
month = {Sat Apr 27 00:00:00 EDT 2019}
}
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