Journal of the Korean Society of Fisheries and Ocean Technology (수산해양기술연구)

The Korean Society of Fisheries and Ocean Technology (한국수산해양기술학회)
권호 표지

A Study of Thermodynamical Reaction Path in Fe-Cr-X Alloys at High Temperature Corrosion Environments

고온 부식환경에 대한 Fe-Cr-X 합금의 열역학적 반응경로에 관한 연구

  • Lee, Byung-Woo (Dept. of Production & Welding Engineering, Pukyong National University) ;
  • Kim, Woo-Yeol (Dept. of Production & Welding Engineering, Pukyong National University)
  • 이병우 (부경대학교 생산가공공학교) ;
  • 김우열 (부경대학교 생산가공공학과)
  • Published : 1996.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

The structure of the scale formed on the surface of Fe - Cr - X alloys exposed to 1143K high sulfidation($Ps_2$ = 1.11$\times$$10^-7$ atm, $Po_2$ = 3.11$\times$$10^-20$ atm) or sulfidation/oxidation(($Ps_2$= 1.06$\times$$10^-7$ atm, ($Po_2$ = 3.11$\times$$10^-18$ atm) environment has been observed and analysed using XRD, SEM/EDS. To investigate the possibility of protective film formed on the surface of the alloys, Aluminium, Nickel were selected as alloying elements. Thermodynamic phase stability diagram was used to predict the reaction path of scale formed on Fe - Cr - X alloys. Parabolic rate constant($K_p$) value with 6wt% Al in Fe - 25Cr alloy decreased significantly compared with the Fe - 25Cr alloy without 6wt% Al. Since thin layer of defect free sulfide film, (Al, Cr)Sx, was formed at the alloy/scale interface. Fe - rich sulfide scale at outer layer and Cr - rich sulfide scale containing porosity at inner layer of Fe - 25Cr alloy have been observed. The reaction path for these scales could be predicted by the thermodynamic stability diagram.

Keywords