Some Remarks on Hydrogen Trapping

A model for the pressure-dependent diffusion and accumulation of hydrogen ahead of a decohesive intergranular crack front is developed. In the model, the pressure dependency of the diffusion is incorporated into the activation energy of an Arrhenius form of the material diffusivity along high-diffusivity grain boundaries. A key feature of the model is the ability to describe the trapping of hydrogen ahead of a decohesive crack front, which is observed in laboratory experiments.