철의 고온 산화반응기구에 관한 연구

A Study on the Mechanism of Oxidation Kinetics oi iron at High Temperatures

A theoretical model was proposed to illucidate the oxidation mechanism of metals for the case in which solid reactants diffuse through the oxide product layer and react with oxygen gas on the surface. This model was derived on the bases of intragranular and intergranular diffusion, also combined with structural parameters such as porosity, grain size and the effective diffusion coefficient of the gas. The oxidation rate of iron which forms the P-type oxide was measured at elevated temperatures. The rate increased with increasing porosity, reaction temperature and oxygen partial pressure. For the case where the diffusion of iron ions through the product layer was the rate determining step, the activation energy for the iron oxidation was 35Kcal/mol. The computer simulation of the model for given boundary conditions was in good agreement with experimental results, and these experimental results were interpreted by the computer simulation.