Computational modeling of pitting corrosion

Abstract

Pitting corrosion damage is a major problem affecting material strength and may result in difficult to predict catastrophic failure of metallic material systems and structures. Computational models have been developed to study and predict the evolution of pitting corrosion with the goal of, in conjunction with experiments, providing insight into pitting processes and their consequences in terms of material reliability. This paper presents a critical review of the computational models for pitting corrosion. Based on the anodic reaction (dissolution) kinetics at the corrosion front, transport kinetics of ions in the electrolyte inside the pits, and time evolution of the damage (pit growth), these models can be classified into two categories: (1) non-autonomous models that solve a classical transport equation and, separately, solve for the evolution of the pit boundary; and (2) autonomous models like cellular automata, peridynamics, and phase-field models which address the transport, dissolution, and autonomous pit growth in a unified framework. We compare these models with one another and comment on the advantages and disadvantages of each of them. We especially focus on peridynamic and phase-filed models of pitting corrosion. We conclude the paper with a discussion of open areas for future developments.

An algorithm for imposing local boundary conditions in peridynamic models on arbitrary domains

“…While PD has been primarily used to deal with mechanical behaviors [26,27,[29][30][31][32], it has also been employed in diffusion-type problems involving cracks and damages, including thermal diffusion [14,[33][34][35] and mass transport (e.g. corrosion) [36][37][38][39][40][41][42]. In peridynamics, each spatial point interacts with other points within its neighborhood which is called the horizon region of and is usually selected to be a disk in 2D (or sphere in 3D) centered at .…”

Dirichlet absorbing boundary conditions for classical and peridynamic diffusion-type models

“…The whole process can be modelled by a PD diffusion solver. It should be pointed out that the solution of such a problem by the standard classical models is cumbersome since the interfacial dissolution flux (between the phases) cannot be defined easily in the framework of local diffusion [28]. This roots from the fact that the concentration field is not smooth at the corrosion front; therefore, capturing the existing jumps (strong discontinuities) is not an easy task for the local models.…”

“…Unfortunately, many of the nonlocal models are inapplicable for problems in which discontinuities (whether strong or weak) in the system emerge, interact, and evolve. Thermal cracking [5,33,65], hydraulic fracturing [43], and pitting corrosion [28] are just a few examples, where part of the solution is governed by diffusion, and, at the same time, they are subjected to the emergence of spontaneous discontinuities.…”

“…More recently, the application of PD to corrosion problems has received a considerable attention [15,28,29,44]. Corrosion problems mainly involve a diffusion process in an electrolyte/solid system coupled with a phase-change mechanism; this results in a moving interface problem.…”

Computer and physical-chemical modeling of the evolution of a fractal corrosion front

“…Для расчета больших областей чаще применяют дискретные модели, которые разбивают расчетную область на блоки и используют математические зависимости и алгоритмы для связи физических величин на границах блоков в предположении, что внутри блоков их значения неизменны. Дискретные модели, работающие в соответствии с правилами локальной эволюции процесса коррозии, являются наиболее востребованными типами моделей для изучения морфологии коррозионного фронта [Jafarzadeh et al, 2019;Chen, Bobaru, 2015;Gabrielli et al, 2000 Santra, Sapoval, 1999]. Хорошее согласие с экспериментальными результатами по питтинговой коррозии показывают численные модели на основе клеточных автоматов, использующие идеи и методы теории перколяции [Gabrielli et al, 2000;Santra, Sapoval, 1999].…”