Corrosion Behavior of Hydrogenated Iron in Oxygen-Containing Sulfuric Acid Solution

By measuring the amount of absorbed oxygen and analyzing the solution by means of photocolorimetry, the effect the cathodic hydrogenation exerts on iron corrosion in an aerated solution of 0.05 N H2SO4 + 1 N Na2SO4 at 20°C is studied. On control samples, the currents of iron dissolution (iFe) and oxygen reduction \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$(i_{{\text{o}}_{\text{2}} } )$$ \end{document} coincide with the limiting diffusion current of the latter \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$(i_{{\text{o}}_{\text{2}} ,d} )$$ \end{document}. In the initial corrosion period of hydrogenated iron, the inequalities \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i_{{\text{o}}_{\text{2}} } \gg i_{{\text{o}}_{\text{2}} ,d} {\text{ and }}i_{Fe} < i_{{\text{o}}_{\text{2}} ,d} $$ \end{document} are valid, which can be explained by the interaction of active hydrogen forms with oxygen at the surface of corroding iron.