Effects of Electrolytic Zirconium Oxide Coating on Hydrogen Permeation of AISI 430 Stainless Steel Available to Purchase

Through Devanathan hydrogen permeation tests and a mathematical analysis, the retarding effect of electrolytic deposition of zirconium oxide (ZrO₂) films on the hydrogen-induced blistering or entry was investigated. The permeation test has indicated that the diffusion coefficient in a metal sheet of AISI 430 (UNS S43000) stainless steel (D_m) was 1.73 × 10^–8 cm²/s and that in ZrO₂ (D_Zr) was 4.74 × 10^–16 cm²/s. Also, the subsurface hydrogen concentration on the metal $(Chm;2.29×10−5mol/cm3)$ was reduced to $(Chm'=0.64×10−5mol/cm3)$ caused not only by a high concentration ratio (K; 8,022) of the oxide film to the metal but also by the extremely low value of D_Zr. Blistering was found on the uncoated specimen after the hydrogen permeation test but was not found on the coated specimen. The electrolytic deposition of ZrO₂ film on the AISI 430 stainless steel demonstrated the retarding effect on hydrogen entry and the occurrence of blistering.