  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.
