Investigation of hydrogen sorption and desorption on steel with cyclic voltammetry employing an inverted rotating disk electrode

摘要

Steel under specific electrochemical conditions may undergo the generation and absorption of atomic hydrogen (H), which diffusion gives rise to diverse H-related issues. Thus, it is fundamental to develop an electrochemical model able to predict the effect of H-diffusion in the lattice of a metal. Hydrogen permeation is ordinarily investigated with the Devanathan-Stachurski cell. However, the acquiring of correct quantitative data is a challenging step in the development of the model Hence, data gathering is accomplished in a well-controlled convection environment through the use of a Rotating Disk Electrode (RDE), which allows controlling the diffusion layer in the electrolyte. The use of an innovative Inverted RDE is employed in order to study the effects of the hydrogen evolution reaction (HER) on the absorption process in steel. The applied method allows the study of the H-uptake and desorption as function of metallurgical conditions of the specimen. Influence of parameters as electrolyte conditions, rotation speed and polarisation scan rate are varied to sort different consequences on the system as surface coverage, HER and adsorption/desorption rate. The aim of this research is to confirm that CV can be used as a reliable method to evaluate H-uptake on steel. The data collected are used to develop a model able to predict the H-generation, diffusion and desorption on steel accounting external parameters influencing the absorption.