Parabolic rate constants steel

This is also reflected in Fig. 2-16, which shows the influence of the chromium content in iron-based alloys, indicating the different oxides formed at the different alloy contents. This diagram shows that the high parabolic rate constants that are observed for unalloyed steel or pure iron can be decreased by about five orders of magnitude when a sufficient amount of chromium is added. It furthermore shows that with increasing chromium content the number of different iron oxides that can be formed is... 

Parabolic rate constant kp of the three low-alloy steels oxidised in laboratory air at 550°C for 72 h. 

Using the oxidation data obtained by Sachs and Tuck [33] for a mild steel equivalent to SAE-AISI1006, by Raman etal [34] for a steel having similar composition, and those by Abuluwefa et al. for a similar steel (Fe-0.04C-0.2Mn-0.02Si) in 1-15% 02-N2[35], an equation was recently derived [6] to calculate the parabolic rate constant of SAE-AISI 1006 steel (or steels having similar compositions) oxidation in air in the range of 700-1250 C ... 

Arrhenius plots of parabolic rate constants for oxidation of 0.06C-0.23Mn steel, as compared to iron oxidation (x) in the same temperature range [36]. 

HELCOR calculates oxidation of both zircaloy and steel by solid-state diffusion through the oxide layer using standard parabolic kinetics, with appropriate rate constant expressions, and limited by steam availability. For zircaloy, the rate constant is evaluated from the correlation by Urbanic and Heldrick. The shift to rapid oxidation is modeled to occur at 1853K [1]. This temperature can be changed via sensitivity coefficient. 

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