Characterization of Hydrogen Permeation Through a Corrosion-Resistant Zinc-Nickel-Phosphorus Alloy Available to Purchase

Hydrogen permeation characteristics of a new Zn-Ni-P alloy were studied and compared with that of a Zn-Ni alloy. The Zn-Ni-P alloy was deposited from an acid sulfate bath containing 0.5 M nickel sulfate (NiSO₄), 0.2 M zinc sulfate (ZnSO₄), 0.5 M sodium sulfate (Na₂SO₄), and 100 g/L sodium hypophosphite (NaH₂PO₂) at pH 3. The permeation characteristics of the alloy were studied and compared qualitatively with that of Zn-Ni alloy under cathodically polarized and corroding conditions. The Zn-Ni-P alloy had better permeation inhibition characteristics in terms of permeation efficiency through the alloy. The Iyer-Pickering-Zamanzadeh (IPZ) model was used to quantitatively estimate the various kinetic parameters associated with hydrogen permeation for Zn-Ni-P alloy under polarized conditions. The Zn-Ni-P alloy had superior permeation inhibition properties compared to the Zn-Ni alloy.