Investigation of Modified Ni-Cr-Mn Base Alloys for SOFC Interconnect Applications

Journal Article · Fri Sep 01 04:00:00 EDT 2006 · Journal of the Electrochemical Society, 153(10):A1873-A1879

DOI:https://doi.org/10.1149/1.2239582· OSTI ID:892887

Yang, Z Gary; Singh, Prabhakar; Stevenson, Jeffry W; Xia, Gordon

Two Ni-Cr-W-Mn base alloys based on Haynes 230 were developed and evaluated against criteria relevant to SOFC interconnect applications, which included oxidation behavior under SOFC operating conditions, scale electrical conductivity, and thermal expansion. It was found that, similar to the ferritic stainless steel Crofer22 APU, additions of Mn led to the formation of a unique scale that was comprised of a M3O4 (M=Mn, Cr, Ni, …) spinel-rich top layer and Cr2O3-rich sub-layer. The modified alloys demonstrated reasonable oxidation resistance under SOFC operating conditions, though the Mn additions increased the scale growth rate and thus sacrificed to some extent the oxidation resistance of the base alloy (Haynes 230). The formation of a spinel-rich top layer improved the scale conductivity, especially during the early stages of oxidation, but the higher scale growth rate resulted in a higher rate of increase in the area-specific electrical resistance. Due to their FCC crystal structure, the Ni-Cr-W-Mn base alloys demonstrated a CTE that was higher than that of anode-supported cells and candidate ferritic stainless steels such as Crofer22 APU.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 892887
• Report Number(s): PNNL-SA-49522; AA2530000
• Journal Information: Journal of the Electrochemical Society, 153(10):A1873-A1879, Journal Name: Journal of the Electrochemical Society, 153(10):A1873-A1879
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ALLOYS
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
OXIDATION
SOFC
SOLID OXIDE FUEL CELLS
STAINLESS STEELS
THERMAL EXPANSION
base alloys
interconnect