A generalised, multi-phase-field theory for dissolution-driven stress corrosion cracking and hydrogen embrittlement

TL;DR

This paper introduces a comprehensive phase field model that unifies stress corrosion cracking and hydrogen embrittlement mechanisms, enabling detailed simulation of environment-material interactions in elastic-plastic solids.

Contribution

It presents the first general multi-phase-field framework for combined stress corrosion cracking and hydrogen embrittlement modeling, validated through numerical simulations and experimental comparisons.

Findings

Model captures transition between corrosion and hydrogen-driven failure.

Simulations agree with benchmark tests and experiments.

Provides new insights into environment-material interactions.

Abstract

We present a phase field-based electro-chemo-mechanical formulation for modelling mechanics-enhanced corrosion and hydrogen-assisted cracking in elastic-plastic solids. A multi-phase-field approach is used to present, for the first time, a general framework for stress corrosion cracking, incorporating both anodic dissolution and hydrogen embrittlement mechanisms. We numerically implement our theory using the finite element method and defining as primary kinematic variables the displacement components, the phase field corrosion order parameter, the metal ion concentration, the phase field fracture order parameter and the hydrogen concentration. Representative case studies are addressed to showcase the predictive capabilities of the model in various materials and environments, attaining a promising agreement with benchmark tests and experimental observations. We show that the generalised formulation presented can capture, as a function of the environment, the interplay between anodic dissolution- and hydrogen-driven failure mechanisms; including the transition from one to the other, their synergistic action and their individual occurrence. Such a generalised framework can bring new insight into environment-material interactions and the understanding of stress corrosion cracking, as demonstrated here by providing the first simulation results for Gruhl's seminal experiments.