TY  - JOUR
AU  - Niewolak, Leszek
AU  - Blum, Ludger
AU  - Peters, Roland
AU  - Grüner, Daniel
AU  - Quadakkers, Willem J.
TI  - Behavior of Metallic Components During 4000 h Operation of an SOFC Stack with Carbon Containing Fuel Gas
JO  - Fuel cells
VL  - 16
IS  - 5
SN  - 1615-6846
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2016-07251
SP  - 600-610
PY  - 2016
AB  - In the present study the behavior of the ferritic interconnect steel Crofer 22 APU and the nickel contacting material during exposure in anode gas of a solid oxide fuel cell (SOFC) stack was investigated. The stack had been operating for 4,000 h and was ten times subjected to thermal cycling within this time period. A temporary high carbon activity in the fuel gas combined with temperature changes resulted in local disintegration of the nickel mesh. Additionally, nickel diffusion from the nickel mesh into the steel resulted in the formation of an austenitic zone. Diffusion of steel constituents into the nickel mesh lead to the formation of Cr,Mn-oxides in the latter. Presence of the nickel/steel contact allows transport of carbon from the gas into the steel, resulting in local internal carburization of the steel. In areas which were not in direct contact with the nickel mesh, the Crofer 22 APU interconnect formed a protective surface oxide scale and no indications for carbon uptake were found. Mechanisms for the experimentally observed effects, including the local disintegration of the nickel mesh, are presented.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000386149300011
DO  - DOI:10.1002/fuce.201600085
UR  - https://juser.fz-juelich.de/record/824693
ER  -