A Mathematical Model for the Determination of Hydrogen Concentration Corresponding to Changes in the Mechanism of Deformation

We propose a three-dimensional mathematical model of hydrogen diffusion in a polycrystalline body taking into account the heterogeneity of diffusion parameters and the solubility of hydrogen in the grain body and on the grain boundaries. The obtained solution is verified for an iron bicrystal. It is shown that the model of grain-boundary diffusion of hydrogen enables one to determine a characteristic value of hydrogen concentration corresponding to changes in the mechanism of deformation.