This article presents a literature review on methods for obtaining adsorption isotherms for organic compounds on metal surfaces from corrosive environments. Approaches that assume a direct relationship between inhibition efficiency and surface coverage are considered. In some studies, the adsorbate surface coverage is determined from gravimetric measurements. Inhibition efficiency was also determined by comparing anodic current densities with and without inhibitors at a constant concentration. Examples of the use of electrochemical impedance spectroscopy, ellipsometry, piezoelectric quartz microbalance, and theoretical calculations in the analysis of organic compound adsorption are also provided.

The current state of the “formal theory” of corrosion inhibition is considered. It is shown that inhibitor protection can be achieved by shielding the metal surface and increasing the activation energy of the corrosion process. The overall corrosion inhibition coefficient is determined by the product of the partial coefficients of corrosion inhibition by the blocking and activation mechanisms. It is demonstrated that the quantitative estimation of the partial inhibition coefficients for both mechanisms is possible for systems whose electrochemical impedance spectra are described by the Mansfeld equivalent circuit. The formulas are analyzed to evaluate the mutual interaction of the components of binary inhibitor mixtures (additivity, synergism, antagonism) using data on the degrees or coefficients of metal protection for the mixtures and their components, as well as corrosion protection times. Mixing chamber inhibitors that do not interact with each other is accompanied by an increase in protection efficiency compared to the individual components.

Modification of polymer composites with microglobules, microcapsules, and microadditives that adapt to the effects of aggressive media makes it possible to realize a gradient distribution of properties of polymer matrices that selectively react with components of an aggressive medium. The increased protective effect of zinc-protective primers is due to the formation of alternating layers of zinc oxides, zinc hydroxides and its complex salt, simonkolleit. The effective mechanism of self-healing of adaptive composites and the prevention of penetration of Cl− to the substrate is due to the formation of simonkolleit in chloride media and the self-healing of defects in epoxy anticorrosive coatings with its help.

This review analyzes the scientific and technical literature devoted to studying the effects of industrial-frequency alternating current on the corrosion of pipe steels (AC corrosion). It describes possible mechanisms of AC corrosion, factors influencing AC corrosion of pipe steels, and indicators of the danger of AC corrosion of pipelines under electrochemical protection. A brief description of international and national standards governing the protection of underground and subsea pipelines from AC corrosion is provided. Studies of AC corrosion of high-strength pipe steels (strength classes X80–X100) are highlighted.

The nature of the limiting stage of the dissolution of (hydr) iron oxides in orthophosphoric acid, which is the transition of the formed surface phosphate complexes on (hydr) iron oxide phases into solution, has been determined; the relationship between the adsorption, kinetic, and electrochemical patterns of the dissolution of (hydr) iron oxide phases has been established. A description of the adsorption phenomena based on the acid-base properties of (hydr) iron oxide phases has been proposed. The processes of complexation of iron(III) cations in highly concentrated solutions of orthophosphoric acid have been studied. It has been established how it affects the kinetics of dissolution (hydra)iron oxides stoichiometry of ironcontaining oxides, the nature of the acid, hydrogen index, concentration of orthophosphoric acid, additives of iron(II) and (III) cations, potential at the boundary (hydra)iron oxide/solution and temperature.

The presence of corrosive agents, such as chlorides, in the atmosphere or water can lead to active pitting corrosion of magnesium-containing aluminum alloys, which include AMg3 alloy. One of the ways to protect them are coatings obtained by chemical oxidation in molybdenum compounds. To increase the anticorrosive properties of such coatings, the introduction of modifying additives into the converting composition and subsequent filling of coatings in a solution of a corrosion inhibitor is used. In this work, we studied the molybdenum coatings modified with combinations of additives: sodium silicate and sodium tetraborate, magnesium nitrate and sodium carbonate. It has been shown that the first combination of additives makes it possible to obtain more stable coatings in terms of protective properties when the temperature of the converting compound changes, the oxidation time varies, and multiple oxidation in a solution.

A superhydrophobic coating (SHPC) on steel obtained by electrodepositing copper and zinc followed by treatment with an ethanol solution of myristic acid is characterized by a contact angle of 157 ±2°. Exposure of coated steel samples for 10 days in the gas and liquid phases of NACE and NaCl (50 g/L) solutions containing 400 mg/L H2S demonstrated a protective effect of over 90% in the gas phase and approximately 15% lower in the liquid phase. At the same time, the coating's superhydrophobicity was maintained. Using potentiodynamic polarization and impedance spectroscopy, it was shown that in a NACE+400 mg/L H2S environment, the coating slows down the anodic process on steel.

In this study, sodium tridecanoate (NaC₁₃) on the surface of a copper alloy in neutral chloride solutions was studied using adsorption, polarization, and gravimetric methods. Ellipsometric measurements revealed the initial adsorption capacity of the NaC_l3 anion on the oxidized alloy surface at E=0.0 V. Calculation of the obtained isotherms using the complete Temkin equation yields an adsorption free energy of 76 kJ/mol. This value indicates chemisorption of the NaC₁₃ anion on the metal. Polarization measurements show that exposure of MNZh5-1 to an inhibited solution for 18 hours increases the local depassivation potential of MNZh5-1 positively, more strongly than in the absence of exposure. Corrosion tests in chloride solutions show that complete protection of the alloy in a 0.01 mol/L NaCl aqueous solution is observed at 6.5 mmol/L NaCl, while in a 0.001 mol/L NaCl solution, complete protection occurs at 0.95 mmol/L NaCl. Preliminary exposure of the alloy to an inhibited solution at a surface concentration required for complete protection of the alloy: up to 4.5 mmol/L NaCl in a 0.01 mol/L aqueous NaCl solution and up to 0.65 mmol/L in a 0.001 mol/L NaCl solution.

As a result of the modeling of the adsorption of iron (II) and phosphate ions on the surface of iron oxide at various pH values, it was shown that the double electric layer (DEL) that occurs at the iron oxide/electrolyte solution interface has a significant impact on adsorption phenomena. In particular, the role of the concentration of hydrogen ions and the potential at the iron oxide/electrolyte solution interface is particularly important. When describing adsorption, it is necessary to take into account the acid-base equilibria that occur at the iron oxide/electrolyte solution interface.

It has been found that the adsorption behavior of iron (II) and phosphate ions in each case is described by a set of five equilibria occurring at the iron oxide/electrolyte solution interface, which correspond to the ideas of the triplet layer model (TLM).

The results of work conducted in the Laboratory of metal corrosion in natural environments over the past 20 years in the area of predicting atmospheric corrosion of metals are reviewed. Atmospheric corrosion models were developed based on statistical processing of data on corrosion mass losses of typical metals (carbon steel, zinc, copper, and aluminum) obtained during large-scale international and Russian programs. Using the developed models, it is possible to assess the aggressiveness category of the atmosphere with respect to a given typical metal, predict its corrosion resistance during long-term operation in various climatic conditions, and develop maps of territories at various geographic scales based on the distribution of estimated corrosion damage over different time periods.