Model to predict intergranular corrosion propagation in three dimensions in AA5083-H131

Abstract

A three-dimensional (3-D) granular model that has the capability of predicting time-dependent intergranular corrosion (IGC) damage propagation depths in AA5083-H131 exposed to 0.6M NaCl solution under potential control is presented. The geometry of grains and degree of sensitization (DoS) of grain boundaries were utilized as inputs, organized in a database, which informed the model to produce IGC depth distributions. The dependencies of IGC depth with exposure time, DoS, and orientation of propagation, both in terms of propagation kinetics and damage morphology, are outputs from the model. The model was calibrated by comparing outputted damage depths to IGC depth data from experiments. Model validation was achieved by comparing the predicted to experimental IGC depths based on image analyses of metallographic cross-section of AA5083-H131 exposed under the same conditions. The relevance and limitations of the current version of the model are discussed.