Electrochemical Behavior of Steel Coated with Organosilicon Self-Organizing Layers

Abstract

Methods have been developed for preliminary modification of the surface of structural metals with compositions based on organosilanes, including both solutions of individual organosilanes and two-component mixtures consisting of two organosilanes or an organosilane with an organic corrosion inhibitor. As a result of this modification, self-organized siloxane polymer/oligomer nanosized layers are formed on the metal surface. Such layers are capable of changing the physical and chemical properties of the metal surface, in particular its electrochemical behavior. In this work, the influence of organosilicon surface layers on the electrochemical behavior of carbon steel, especially on the anodic local dissolution of the metal, is studied in detail. Inhibition of metal dissolution by surface layers has been shown. It has been established that the greatest inhibitory effect is exhibited by two-component modifying compositions, namely, mixtures of vinylsilane with aminosilane and vinylsilane with benzotriazole. The mechanism of corrosion inhibition by surface nanolayers formed during surface modification with two-component mixtures is considered.