Calculation of Boundary Conditions between Internal and External Oxidation of Silicon or Chromium Containing Steels

Abstract:

Article Preview

The boundary constants between internal and external oxidation of Si or Cr containing steels (Fe-Si alloys or Fe-Cr alloys) at 850°C were calculated in order to clarify the formation mechanism of fayalite scale (Fe2SiO4) or chromite scale (FeCr2O4), which can form as a “sub-scale” in Si or Cr containing steels. The diffusion coefficient of oxygen in the alloy, Do, and the oxygen concentration at the specimen surface, NO(s), which are constituents of the internal oxidation rate constant, (2DONO(s)/NB(O)n), were calculated for various oxidation conditions, and the rate equation for internal oxidation was derived. By comparing the calculated and measured values of (2DONO(s)/NB(O)n), we confirmed that the rate equation determined for internal oxidation was reasonable. The boundary condition between internal and external oxidation of Si or Cr containing steels (Fe-Si alloys or Fe-Cr alloys) at 850°C were also calculated by substituting the calculated values of DO and NO(s) into the rate equation.

Info:

Periodical:

Edited by:

Toshio Maruyama, Masayuki Yoshiba, Kazuya Kurokawa, Yuuzou Kawahara and Nobuo Otsuka

Pages:

88-93

DOI:

10.4028/www.scientific.net/MSF.696.88

Citation:

S. Nakakubo et al., "Calculation of Boundary Conditions between Internal and External Oxidation of Silicon or Chromium Containing Steels", Materials Science Forum, Vol. 696, pp. 88-93, 2011

Online since:

September 2011

Export:

Price:

$35.00

In order to see related information, you need to Login.

In order to see related information, you need to Login.