Different Impacts on the Corrosion Behavior of Metal–Metal Glassy Alloys in Sulfuric Acid

Electrochemical techniques were used to investigate different factors such as concentration, immersion time, and temperature on the corrosion behavior of the metal–metal glassy Fe78Co9Cr10Mo2Al1 (VX9) and Fe49Co49V2 (VX50) (at.%) alloys in sulfuric acid (H2SO4). The passive film on the surface of the alloys at different H2SO4 concentrations was analyzed by X-ray photoelectron spectroscopy, and examined by scanning electron microscope and atomic force microscopy. The electrochemical measurements illustrate that the VX9 alloy has a lower corrosion resistivity than the VX50 alloy in all measured effects in this study, due to the n-type semiconductor passive layer (FeOOH, Fe3O4, and Fe2O3) that forms on this alloy. This occurred even though these alloys demonstrated a high degree of resistance at higher concentrations (12.0 M) of H2SO4 solution. A decrease in the corrosion resistance and an increase in the corrosion rate was observed with the incremental increase of immersion time and temperature. The thermodynamic parameters, such as Ea∗\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{E}}_{{\text{a}}}^{*}$$\end{document}, ΔS* and ΔH*, were evaluated for the corrosion process and discussed in terms of a 3.0 M H2SO4 solution.