Intergranular corrosion: Comparison between experiments and cellular automata

Abstract

In this paper, a 3D cellular automata approach of intergranular corrosion in presented. A model is proposed, along with experimental results both qualitatively (groove morphology, groove angle distribution) and quantitatively (mass loss, corrosion rate, corrosion front evolution). Simulations have been performed using a new asynchronous algorithm: the choice of the most adequate grid is also discussed. The model investigates the statistical variation of the corrosion front and provides useful information to make predictions on material ageing.

Intergranular corrosion in evolving media: Experiment and modeling by cellular automata

“…For this last one, as it was difficult to extract information from experiments, we used CA modeling. Indeed, we showed that CA is able to reproduce accurately the experimental behavior [33,47].…”

“…These probabilities drive the evolution of the system from a time t to the following time t + Δt, according to transition rules: a IGN (or GRN) cell that is contact with a SOL cell has a probability Pgrn (or Pign) to convert into a SOL cell. The way to fix the values of Pign and Pgrn so as to reproduce adequately the experimental results (with CA to experiments conversion factors) is described in reference [33].…”

“…From the experimental point of view, different techniques are used to characterize IGC. In addition to qualitative observations of the surface, optical or scanning electron microscopy can be performed on the cross section of the sample to geometrically characterize the intergranular grooves in 2D [15,[24][25][26][27][28][29][30][31][32][33]. A promising 3D characterization approach has also been attempted by µ-Xray-tomography [34].…”

“…A promising 3D characterization approach has also been attempted by µ-Xray-tomography [34]. The measurement of the mass loss as the function of time gives also important information regarding the kinetics of IGC [18,24,26,[29][30][31][35][36][37][38][39][40][41]. Sometimes, the chemical characteristics of the surface are analyzed by X-ray photoelectron spectroscopy (XPS) [26,38,42,43].…”

“…A geometrical approach in 2D was developed for simulating the evolution of the material/solution interface morphology during IGC [31,44]. More realistic models were also developed using the method of cellular automata (CA) for simulating the geometrical evolution of the material in a 3D realistic granular structure [15,41,[45][46][47][48].…”