Process of hydrogen discharge on the metal surface in the corrosion fissure of steel

Abstract

The effects of secondary reactions in metal-medium systems on their initial properties have been analyzed, and the role of primary physical-chemical processes in creating conditions for the onset of the kinetic characteristics of hydrogen discharge on a metal surface has been evaluated. Based on the results of physical studies (using mass spectrometry, thermodesorption, and atomic absorption spectroscopy) the principal physical chemical aspects of the theory of electrochemical hydrogen discharge on a metal surface have been established, and the dynamics of hydrogen redistribution or partitioning between the interphase boundaries and the bulk phase have been investigated; the effects of these processes on the evolution of metal-medium systems have also been demonstrated. The primary act which determines the energetics of the entire process of the interaction of fluid media with a metal surface has been shown to be the adsorption and subsequent exothermic chemichemisorption of solvent molecules on active surface sites. This facilitates bond redistribution (including or up to complete dissociation of index groups of the solvent on the metal surface), which in turn delivers or supplies protons for the ensuing discharge, molization, and occlusions of hydrogen by the metal.