Abstract

Future technologies require structural materials resistant to environmental degradation in high-temperature CO₂-rich environments. In this work, we exposed several commercially available Ni-based alloys (230, 263, 282, 617, 625, and 740H) to atmospheric pressure gases intended to simulate the compositions expected in future direct-fired supercritical CO₂ power cycles. The alloys were exposed to 95% CO₂ + 4% H₂O + 1% O₂ and the same gas containing 0.1% SO₂ at temperatures of 600, 650, 700, 750, and 800 °C for 2500 h. With minor exceptions, chromia scales formed on all alloys at all temperatures in the SO₂-free gas, yielding parabolic growth rates that followed an Arrhenius temperature dependence. Behavior in the SO₂-containing gas was more complex. Generally, the alloys performed well at temperatures of 650, 750, and 800 °C. While some alloys further performed relatively well across the whole temperature range, several of the alloys experienced chromia failure resulting in non-protective duplex oxide scales and high oxidation rates, at temperatures of 600 and 700 °C. Deviation from protective behavior was associated with internal sulfide formation and, additionally for the case of 600 °C, external sulfate formation. Extensive carburization accompanied growth of the non-protective duplex oxide scales, which made it more difficult formore » the alloy to recover after initiation of the sulfur-induced accelerated corrosion process. The thermodynamic and kinetic factors influencing the accelerated corrosion in the presence of sulfur are discussed. The results suggest that caution is required when assessing compatibility of Ni-based alloys for CO₂-based systems when sulfur-based impurities are expected.« less

Authors:

Oleksak, Richard P.  ^[1];

• Search DOE PAGES for author "Oleksak, Richard P."
• Search DOE PAGES for ORCID "0000-0003-4642-8152"

Tylczak, Joseph H.  ^[1];

• Search DOE PAGES for author "Tylczak, Joseph H."
• Search DOE PAGES for ORCID "0000-0002-0391-2350"

Teeter, Lucas  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-2412-4633"

Carney, Casey S.  ^[1];

• Search DOE PAGES for author "Carney, Casey S."
• Search DOE PAGES for ORCID "0000-0002-6311-4641"

Doğan, Ömer N.  ^[1]

• Search DOE PAGES for author "Doğan, Ömer N."
• Search DOE PAGES for ORCID "0000-0002-3187-2026"

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+ Show Author Affiliations

1. National Energy Technology Lab. (NETL), Albany, OR (United States)

Publication Date:

Fri Sep 29 00:00:00 EDT 2023

Research Org.:

National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)

Sponsoring Org.:

USDOE Office of Fossil Energy and Carbon Management (FECM)

OSTI Identifier:

2007803

Resource Type:

Accepted Manuscript

Journal Name:

High Temperature Corrosion of Materials

Additional Journal Information:

Journal Volume: 100; Journal ID: ISSN 2731-8397

Publisher:

Springer

Country of Publication:

United States

Language:

English

Subject:

direct-fired supercritical CO2 power cycle; Ni-based superalloys; oxidation; sulfidation; carburization