Evaluation of Ni-Cr-Base Alloys for SOFC Interconnect Applications

Journal Article · Fri Oct 06 04:00:00 EDT 2006 · Journal of Power Sources, 160(2):1104-1110

DOI:https://doi.org/10.1016/j.jpowsour.2006.02.099· OSTI ID:895456

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

To further understand the suitability of Ni-Cr-base alloys for solid oxide fuel cell (SOFC) interconnect applications, three commercial Ni-Cr-base alloys, Haynes 230, Hastelloy S and Haynes 242 were selected and evaluated for oxidation behavior under different exposure conditions, scale conductivity and thermal expansion. Haynes 230 and Hastelloy S, which have a relatively high Cr content, formed a thin scale mainly comprised of Cr2O3 and (Mn,Cr,Ni)3O4 spinels under SOFC operating conditions, demonstrating excellent oxidation resistance and a high scale electrical conductivity. In contrast, a thick double-layer scale with a NiO outer layer above a chromia-rich substrate was grown on Haynes 242 in moist air or at the air side of dual exposure samples, indicating limited oxidation resistance for the interconnect application. With a face-centered-cubic (FCC) substrate, all three alloys possess a coefficient of thermal expansion (CTE) that is higher than that of candidate ferritic stainless steels, e.g. Crofer22 APU. Among the three alloys, Haynes 242, which is heavily alloyed with W and Mo and contains a low Cr content, demonstrated the lowest average CTE at 13.1x10-6 K-1 from room temperature to 800oC, but it was also observed that the CTE behavior of Haynes 242 was very nonlinear.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 895456
• Report Number(s): PNNL-SA-49521; AA2530000
• Journal Information: Journal of Power Sources, 160(2):1104-1110, Journal Name: Journal of Power Sources, 160(2):1104-1110
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ALLOYS
ELECTRIC CONDUCTIVITY
EVALUATION
FCC LATTICES
HASTELLOY S
OXIDATION
SOFC
SOFC interconnect
SOLID OXIDE FUEL CELLS
SPINELS
STAINLESS STEELS
SUBSTRATES
THERMAL EXPANSION
alloys
high temperature alloys
oxidation
oxide fuel cell