The study of hydrogen permeation behavior in Armco-Fe showed that 0.1M H2SO4 was a more effective medium for cathodic polarization as compared with 0.1M NaOH. When both electrolytes were poisoned with 1.00g/l Na2HAsO4•7H2O, as a hydrogen recombination inhibitor, the corresponding hydrogen permeation levels were 3.5 x 10−5A/cm2 in 0.1M H2SO4 but 0.75 x 10−5A/cm2 in 0.1M NaOH. The breakthrough times were less than 30s in 0.1M H2SO4, but about 100s in the NaOH. With varying amounts of poison, the peak permeation of hydrogen (1.75 x 10−5A/cm2) was achieved with 10g/l Na2HAsO4•7H2O in 0.1M H2SO4, while the least permeation resulted with 10g/l (NH2CSH2) Thiourea addition for the same level of 1.00mA/cm2 cathodic polarization.

Characterization of Hydrogen Permeation in Armco-Fe during Cathodic Polarization in Aqueous Electrolytic Media. S.M.Charca, O.N.C.Uwakweh, B.Shafiq, V.S.Agarwala: Journal of Materials Engineering and Performance, 2008, 17[1], 127-33