A phase-field framework for stress corrosion cracking prediction in elastoplastic metallic materials

To capture the stress corrosion cracking (SCC) in metallic materials, a phase-field framework considering localized plastic deformation and stress states is established. A new function of critical energy release rate is proposed to describe the degradation of cracking resistance of materials in the SCC process. This proposed framework can reproduce SCC results consistent with experimental observations in C-ring steel SCC tests, especially capturing the directionally characteristic of the cracks. Furthermore, the influences of localized plastic deformation and stress states on the SCC process are studied. This novel phase-field framework can capture (1) the influences of coupled electricity, mechanics to the SCC mechanisms; (2) the contribution of plastic strain energy as the driving force for the phase-field; (3) the potential and preferential crack initiation and propagation morphology within the complex stress and strain domain; and (4) the dependence of SCC rate and propagation direction on stress state and localized plastic deformation. A phase-field framework for SCC prediction of elastoplastic materials is established. The novel framework is implemented in finite element model and validated by tests. The framework can capture SCC morphology within the complex stress and strain domain. Influences of stress states and localized plastic deformation on SCC are clarified.