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

Shohei Nakakubo; Mikako Takeda; Takashi Onishi

doi:10.4028/www.scientific.net/MSF.696.88

Paper Titles

In Situ Measurement of the Phase Transformation Behavior of Al₂O₃ Scale during High-Temperature Oxidation using Synchrotron Radiation
p.63

The early Stages of the Scale Growth on FeCrAl(+RE)-Type Alumina Formers
p.70

Thermodynamic Stability and Reaction Sequence for High Temperature Oxidation Processes in Steels
p.76

Modeling Internal Oxidation of Binary Ni Alloys
p.82

Calculation of Boundary Conditions between Internal and External Oxidation of Silicon or Chromium Containing Steels
p.88

Scale Surface and Scale/Alloy Interface for Alumina-Forming Alloys with Noble Metal and Yttrium
p.94

Failure Characteristics of Scales Formed on Si-Containing Low Carbon Steels during Cooling - Influences of Cooling Rate and Water Vapor
p.101

High Temperature Oxidation of Advanced High Strength Steel: HT-XRD Method for Quantitative Evaluation
p.107

High-Temperature Oxidation of Low-Carbon Steel Coated by Solution-Spraying with Cerium and Aluminum Ions
p.114

HomeMaterials Science ForumMaterials Science Forum Vol. 696Calculation of Boundary Conditions between...

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

Abstract:

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, N_O^(s), which are constituents of the internal oxidation rate constant, (2D_ON_O^(s)/N_B^(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 (2D_ON_O^(s)/N_B^(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 D_O and N_O^(s) into the rate equation.