A level set model for stress‐dependent corrosion pit propagation

Abstract

A numerical model for corrosion pit propagation under mechanical loading is presented. The level set method is used for corrosion front tracking and also enables the domain to be split into a solid and a pit domain. In the pit the diffusion of atoms originating from the dissolution process occurring at the pit front is simulated. The model is capable of automatically capturing lacy cover formation due to the inclusion of activation control, diffusion control, and passivation. In the solid static equilibrium is solved to obtain strains and stresses. A parameter, dependent on the signs of the plastic strain increment and the back stress, is introduced to define the influence of plasticity on the corrosion rate. The model is used to study pit growth under electrochemical and mechanical loading. Under activation control combined with an elastic material response, pits propagate faster under constant loading than under cyclic loading. When plastic deformation occurs, cyclic loading can significantly increase the pit growth rate. Increasing the cyclic load frequency results in faster propagation due to kinematic hardening. Under diffusion control, mechanical loading does not influence the pit growth rate, given that the salt layer leading to diffusion control remains intact.

Electro-chemo-mechanical phase field modeling of localized corrosion: theory and COMSOL implementation

“…However, these works are limited by the assumption of a stationary electrolyte-metal interface. On the other hand, a number of computational schemes have been recently presented to track the evolution of the corrosion front [7][8][9][10][11][12][13][14]. Among these, the phase field model stands out for its thermodynamics roots and its ability to efficiently capture corrosion morphologies of arbitrary complexity.…”

Parallel Computing with the Thick Level Set Method

“…One possible option to achieve better scaling for the level-set-related operations in the level set update and front evolution phases would be to use the weak form, and its discretization, to solve the reinitialization and velocity extension problems following Adams, Giani, and Coombs [1] and Dekker et al [5]. In this approach, we have systems of equations for both problems which can also be solved by the parallel iterative solver.…”

A phase field model to simulate crack initiation from pitting site in isotropic and anisotropic elastoplastic material

“…The need for capturing multiple chemical and mechanical phenomena, and their interplay, is one of the most major challenges in predicting environmentassisted failure [9,10]. Another important challenge is the interfacial nature of the corrosion and fracture problem, that requires tracking the evolution of corrosion front and/or crack propagation at the solid/environment interface [11][12][13].…”