Computer-based simulation of kinetics of internal corrosion of engineering alloys at high-temperatures

• Autor(a) principal: Trindade,Vicente Braz
• Data de Publicação: 2009
• Outros Autores: Christ,Hans-Jürgen, Krupp,Ulrich
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: REM. Revista Escola de Minas (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0370-44672009000200009
• topic: Internal nitridation; oxidation; computational thermodynamics; ChemApp; InCorr; finite difference

A reasonable prediction of the service life of structures or equipment operating at high-temperatures in aggressive atmospheres requires a full understanding of the degradation mechanisms of the material due to mechanical loading and corrosion. The overall objective of this study is to simulate high-temperature corrosion processes under near-service conditions, which require both, a thermodynamic model to predict phase stabilities for given conditions and a mathematical description of the kinetic process, i.e., solid state diffusion. A computer program was developed in which the thermodynamic program library ChemApp is integrated into a numerical finite-difference diffusion calculation to treat internal oxidation, nitridation and sulfidization processes in various commercial alloys. The model is capable of simulating multi-phase internal corrosion processes controlled by solid-state diffusion into the bulk metal as well as intergranular corrosion occurring in low-alloy steels by fast inward oxygen transport along the grain boundaries of the substrate. In this article, dilute and monophase solutions are considered.