Hydrogen diffusion and trapping in nickel

Abstract

Analysis of hydrogen transport in nickel has shown that both trapping and short-circuit diffusion occur and both have small but significant effects on permeation, evolution and absorption. Both effects appear to be associated primarily with the dislocation substructure of nickel. The data from this study of deuterium permeation and tritium absorption and outgassing in pure polycrystalline nickel, both annealed and heavily cold-rolled, were evaluated and combined with earlier measurements of diffusivity and solubility of hydrogen isotopes to yield the following relations for describing hydrogen transport in nickel: Diffusivity (D) = 7.0 × 10 −7 √M exp( −39,500 RT ), m 2/sec Solubility (C) = 1.1 × 10 3 exp ( −15,800 RT ), mole (H)/ m 3 Permeability (φ) = 7.9 × 10 −4 √ M ̄ exp ( −55,300 RT ), mole (H)/ sec/√Mpa) .