Dislocation-Based Finite Element Modelling of Hydrogen Embrittlement in Steel Alloys

Mechanical properties of many metals are greatly influenced by hydrogen solutes causing a well-known phenomenon of Hydrogen Embrittlement (HE). Hydrogen atoms affect the dislocation core, materials cohesion, and/or vacancies clustering causing the material capacity for plastic deformation to decrease. Such degradation in performance of metals leads to embrittlement resulting of catastrophic failure in structures. In this research, a physically-based constitutive model is developed to study hydrogen embrittlement in steel alloys. The developed model is an extension for Ghoniem-Matthews-Amodeo (GMA) dislocation-based model in order to predict the constitutive relation in the plastic regime for high strength steel alloys while considering hydrogen Effect on plasticity. The proposed physically-based dislocation-density model include the effect of hydrogen solute on dislocation mobility and interaction. The proposed model study the mechanical behavior of high-strength steel of HT-9 tensile test specimen.