Investigations of the hydrogen evolution kinetics and hydrogen absorption by iron electrodes during cathodic polarization

Long-lasting hydrogen evolution on and hydrogen entry into iron in an aqueous solution

“…The majority of the experimental data, obtained using the technique of Devanathan and Stachursky [2], shows that the entry of hydrogen into iron cathodically charged in alkaline solutions is lower than that observed in acid solutions. For a moderate cathodic current density of about 10 mA cm À2 , the product of the steady state permeation rate and the membrane thickness ðj 1 p  LÞ is of the order of 0.1 lA cm À1 in NaOH solutions [3][4][5][6][7], and about 1 lA cm À1 in H 2 SO 4 solutions [4,7,8]. The above ratio corresponds to the quasi-steady state permeation rate observed after a rather short (less than 1 h) charging.…”

Chemomechanical effects on the separation of interfaces occurring during fracture with emphasis on the hydrogen-iron and hydrogen-nickel system

“…The activity of the latter part can be obtained by measuring its permeation through a metal membrane. Thus large fugacities were measured for iron in an electrolyte of sulfuric acid containing small amount of arsenic oxide [30]. Defining activity as a H = 1 for p = 1 bar values of up to a H = 1000 have been measured at room temperature for cathodic current densities of 30 mA/cm 2 .…”

Quantification of hydrogen diffusion and trapping in 2.25Cr-1Mo and 3Cr-1Mo-V steels with the electrochemical permeation technique and melt extractions

“…Cathodic charging from 0.1N NaOH at Ϫ1350 mV/SCE leads to steady-state flux values, which are smaller than those measured in 1N H 2 SO 4 at 5 mA/cm 2 . This situation can be attributed to the lower hydrogen activity associated with the higher pH of alkaline solutions, which results in smaller hydrogen coverage of the input surface, [26,27] and to the value of the applied potential. For a given material, the hydrogen steady-state flux through pearlite was reported to be larger than through bainite.…”