Study on the NiAl Coating for Corrosion Resistance of Stainless Steel in Molten Carbonate Salt

용융탄산염에 대한 스테인레스강의 내식성 향상을 위한 NiAl 피복에 관한 연구

  • Published : 1997.01.01

Abstract

'4 NiAl coating process was applied on 316 stainless steel to retard the corrosion of the wet- seal area of separator for the molten carbonate fuel cell. The Nit11 phasc on the stainless steel substrate could be formed by pre-coating with Ni, plated with A1 and ther, heat treated at $800^{\circ}C$ for 3 hr in $H_2/N_2$ gas atmosphere. The corrosion protection behavior of YiAl coating layer was stuilied under immersion condition in molten cxhonate salt($62^{m}/_{o}Li_2CO_3-38^{m}/_{o}/K_{2}CO_{3}$) at $650^{\circ}C$. The NiAl coating layer ticposited on the AiSi 316 stainless steel had high corrosion resistance in molten carbor. dte salt. The corrosion resistance of XiAl (~~jpoared to be associated with the .A1 oxide formed on the surface of coating layer.

용융탄산염 연료전지 분리판의 wet-seal부의 내식성 향상을 위한 NiAl 피복공정이 조사되었다. AlSl 316 스테인레스강위에 Ni과 Al를 순차적으로 피복한 후, $800^{\circ}C$에서 3시간 열처리하여 NiAl상이 형성됨을 확인할 수 있었다. NiAl상이 피복된 스테인레스강은 $650^{\circ}C$, 용융탄산염($62^{m}/_{o}Li_2CO_3-38^{m}/_{o}/K_{2}CO_{3}$)내에서 침지시험을 통해 내식성이 평가되었는데, AISI 316 스테인레스강에 비해 우수한 내식성을 보였다. 이는 표면에 치밀하게 형성된 AI 산화물층에 의한 것으로 판단되었다.

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References

  1. Denki Kagaku v.59 T. Kahara;K. Ohtsuka;T. Takahashi
  2. J. Electrochem. Soc. v.131 R.A. Donado;L.G. Marianowski;J.R. Selman
  3. Proc. 3rd Symp. Carbonate Fuel Cell Technology, PV93-3, The Electro-chem. Soc. v.158 C. Yuh;R. Johnsen;M. Farooque;H. Maru
  4. The superalloys A.M. Beltran;D.A. Shores
  5. Metal Sci. R. Hutchings;M.H. Loretto
  6. J. Appl. Phys. v.58 E.G. Colgan;M. Nastasi;J. W. Mayer
  7. Trans. TMS-AIME v.239 M.M. P. Janssen;A.D. Rieck
  8. 鐵 と鋼 v.68 K. Onisawa;M. Chigasaki;K. Soeno