Numerical Simulation of High Temperature Corrosion Processes in Mn, Cr, Si, Al – Alloyed Steel Samples

The grain boundary oxidation mechanism in hot rolled steel samples during cooling from 500 °C – 800 °C down to room temperature was mathematically modeled. Given a fixed temperature ramp, the migration of the atomic species (iron, oxygen and the alloying elements) has been calculated with the parabolic rate equation for diffusion. After each small time step, the data was transferred into the database ChemApp (GTT-Technologies, Germany) to calculate the oxide composition for each point in thermodynamic equilibrium. The concentrations for each phase were illustrated in a phase map, similar to a cross section polish of the respective specimen. Total element concentration is shown as height plot to better pronounce the increased amount of oxidic phases along the grain boundaries. The obtained results are in good agreement with experimental data for low alloyed steel samples.