A generalised model of hydrogen diffusion in metals with multiple trap types

作者：Toribio Jesus; Kharin Viktor^*

来源：Philosophical Magazine, 2015, 95(31): 3429-3451.

DOI：10.1080/14786435.2015.1079660

• hydrogen diffusion
• trapping
• continuum modelling
• hydrogen embrittlement

Continuum modelling of hydrogen diffusion in metals, which accounts for both trapping and an imposed force field, is revisited. A generalised model of hydrogen diffusion and trapping is developed as a continuous interpretation of the discrete random-walk theory. A system of nonlinear equations describing the phenomenon of diffusion with multiple types of traps is derived without the assumption of a local equilibrium among hydrogen populations in dissimilar positions. Lattice-trap interchange kinetics can degenerate into local equilibrium as a limit case. Moreover, certain terms in general equations may be negligible in specific situations. By removing these terms, known particularised models of hydrogen diffusion and trapping are recovered. Determining the terms, which are disregarded in reduced models, enables a straightforward assessment of the applicability of these models. The advantages and limitations of particularised models applied to hydrogen embrittlement analyses are discussed.

• 出版日期2015-11-2