High-Temperature Oxidation Behavior of Wrought and Additive Manufactured Alloys in Direct-Fired Supercritical CO2 Power Cycle Environments

Conference · Mon Feb 26 00:00:00 EST 2024

OSTI ID:2311821

Carney, Casey ^[1]; Oleksak, Richard ^[2]; Lamprinakos, Nicholas ^[3]; Rollett, Anthony ^[3]; Dogan, Omer ^[2]

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1. NETL Site Support Contractor, National Energy Technology Laboratory
2. NETL
3. Carnegie Mellon University (CMU)

Materials selection is a key concern for corrosion resistance in elevated temperature and pressure direct-fired supercritical CO2 (sCO2) power cycles. The effect of elevated pressure on corrosion resistance can be critical, as impurities within the supercritical fluid such as H2O and O2 can have additional corrosion effects than found at ambient pressure conditions. Several wrought nickel-based commercial alloys (230, 263, 282, 617, 625, 740H) were exposed to direct-fired conditions (95CO2 – 4H2O – 1 O2) at 750 °C at both atmospheric pressure (0.1 MPa) and supercritical conditions (20 MPa) for over 2,000 h. Additionally, additive manufactured (AM) 282 produced by laser powder bed fusion (LPBF) were also included in the exposures. Supercritical conditions affected the oxidation behavior of several alloys. Most notably, water-vapor assisted Cr-oxide volatilization was observed at 750 °C supercritical conditions. Many alloys did not form sufficient protective Cr-oxide scales at supercritical conditions, leading to increased oxidation at elevated pressure. Differences in oxidation behavior were also observed for 282 AM samples compared to their wrought counterparts, with the differences also dependent on the LPBF build parameters and post-production treatments (heat treatment and surface finishing procedures). The AM samples formed Mo-rich carbides in the alloy beneath the oxide following sCO2 exposure, implying potentially higher levels of carbon uptake relative to the wrought

• Research Organization: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• OSTI ID: 2311821
• Resource Relation: Conference: Conference Name: 8th International Supercritical CO2 Power Cycles Symposium Location: San Antonio, Texas, United States Start Date: 2/26/2024 12:00:00 AM End Date: 2/29/2024 12:00:00 AM
• Country of Publication: United States
• Language: English