Evaluation of STS 430 and STS 444 for SOFC Interconnect Applications

  • Kim, S.H. (Department of Materials Science and Engineering, Korea University) ;
  • Huh, J.Y. (Department of Materials Science and Engineering, Korea University) ;
  • Jun, J.H. (New Materials & Components Research Center, Research Institute of Industrial Science and Technology) ;
  • Kim, D.H. (New Materials & Components Research Center, Research Institute of Industrial Science and Technology) ;
  • Jun, J.H. (New Materials & Components Research Center, Research Institute of Industrial Science and Technology)
  • Published : 2007.02.01

Abstract

Ferritic stainless steels for the SOFC interconnect applications are required to possess not only a good oxidation resistance, but also a high electrical conductivity of the oxide scale that forms during exposure at the SOFC operating environment. In order to understand the effects of alloying elements on the oxidation behavior of ferritic stainless steels and on the electrical properties of oxide scales, two kinds of commercial ferritic stainless steels, STS 430 and STS 444, were investigated by performing isothermal oxidations at $800^{\circ}C$ in a wet air containing 3% $H_{2}O$. The results showed that STS 444 was superior to STS 430 in both of the oxidation resistance and the area specific resistance. Although STS 444 contained a less amount of Mn for the $(Mn,Cr)_{3}O_{4}$ spinel formation than STS 430, the minor alloying elements of Al and Mo in STS 444, which were accumulated in the base metal region adjacent the scale, were suggested to reduce the scale growth rate and to enhance the scale adherence to the base metal.

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References

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