Mechanisms of hydrogen embrittlement under multiaxial stress/strain fields framework: a review

Purpose The purpose of this study is to analyze the stress-strain fields of defects in different dimensions, and to summarize their relationship with hydrogen embrittlement. Design/methodology/approach This study proposes a dynamic framework centered on stress fields, conceptualizing defects as stress concentration regions operating across multiple scales. Findings At the one-dimensional level, modifying dislocation cores and reducing Peierls barrier heights enables the formation of Cottrell atmospheres and the activation of the hydrogen-enhanced localized plasticity effect. On the two-dimensional level, coincidence site lattice boundaries and low-angle grain boundaries contribute to preventing hydrogen buildup by smoothing out stress distributions. In three-dimensional, factors such as lattice misfit and residual stresses arising from phase transformations make it possible to differentiate between shallow traps at interfaces and deeper. Originality/value This study introduces a unified, scale-resolved framework that systematically links one-dimensional dislocation dynamics, two-dimensional grain boundary misorientation effects and three-dimensional carbide interface trapping mechanisms through a common stress-field perspective, offering an integrated multiscale understanding of hydrogen embrittlement that transcends isolated defect analyses.