The review tells about the history of corrosion studies at the A.N. Frumkin Institute of Physical Chemistry and Electrochemistry. The stages of the study of inorganic and organic compounds on the surface of metals in aqueous solutions are described in detail. It is also possible to get acquainted with the current activities of the Laboratory of Physicochemical Foundations of Inhibition of Metal Corrosion at the Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences.

The adsorption, protective and passivating action of substituted triazoles, namely, 5-nonylsulfonyl-3-amino-1,2,4-triazole and 5-propylsulfonyl-3-amino-1,2,4-triazole on the oxidized surface of zinc in a neutral buffer solution was studied. It is shown that 5-nonylsulfonyl-3-amino-1,2,4-triazole anions have higher values of free energy of adsorption0 a ,max( )G on zinc at E = 0.2 V compared to 3-amino-1,2,4-triazole. The values calculated using the complete Temkin isotherm are 83 and 82 kJ/mol for 5-nonylsulfonyl-3-amino-1,2,4-triazole and 5-propylsulfonyl-3-amino-1,2,4-triazole, respectively. Such high values reliably suggest chemisorption interaction of these organic anions with the oxidized zinc surface.

An effective inhibitor of corrosion of St3 steel in solutions of sulfuric and phosphoric acids has been developed based on the pharmaceutical drug for veterinary purposes – oxytetracycline. It has been established that in individual form this pharmaceutical preparation does not provide significant protection of steel in the studied environments. Its use in the form of a two-component mixture with NH₄NCS is more promising. A composite inhibitor of 0.1−0.2%   oxytetracycline+0.01% NH₄NCS has been proposed, which is capable of providing effective long-term protection of steel in H₂SO₄ solutions with a wide range of acid concentrations (0.25−2.00 M) and temperatures t = 20−80°C. This mixture significantly slows down corrosion of low-carbon steel in 1.00 M H₃PO₄ at temperatures up to 95°C. The developed composition is no worse in its effectiveness in inhibiting steel corrosion in H₂SO₄ and H₃PO₄ solutions in comparison with similar mixed inhibitors created on the basis of an industrial surfactant – cocamidopropyl betaine and a veterinary drug – tricillin.

The protective effect of captax, phenylthiourea (PTU), diphenylthiourea (DPTU), sodium diethyldithiocarbamate (DEDTC) and tall oil monoethanolamide (MEAT), as well as mixtures of MEAT with sulfur-containing organic substances during corrosion of steel 3 in 0.5 M sulfuric acid solution has been studied by gravimetry, polarization curve removal and impedance spectroscopy. It was found that at the studied concentrations, MEAT, captax, DPTU, PTU and DEDTC provide protection of steel from corrosion in sulfuric acid at 73÷91%, 21÷97%, 66÷98%, 19÷90%, and 25÷42% at a temperature of 20°C, respectively. A mixture of MEAT (0.5%) with organic sulfur-containing substances (10− 5 ÷10− 4 M) protects steel at the specified temperature by 85÷99%. As the temperature increases, the effectiveness of individual compounds and inhibitory mixtures decreases. The influence of the components and their mixtures on the particular electrode reactions of the corrosion process has been established. The degree of surface filling with inhibitors and the amount of free adsorption energy were determined.

The possibility of predicting the first-year corrosion losses of typical structural metals (carbon steel, zinc, copper, and aluminum) at extremely high rates of chloride deposition on the material surface is shown. The thickness of water retained by metal corrosion products after one-year exposure of samples to the open atmosphere is estimated. It is shown that in order to use the high/extreme rate of chloride deposition observed in months with typhoons/hurricanes, it is necessary to estimate the thickness of the deposited aerosols and the possibility of their flowing off the surface of the samples. To predict one-year corrosion losses of metals, it is necessary to take into account only a fraction of the rate of chloride deposition on the "wet candle" sampler. Based on the data obtained at the NRC "Kurchatov Institute" – VIAM, a model of the rate of chloride deposition was developed taking into account high wind speeds.

The effect of inhibition and holding time of low-carbon steel in 10% (NH₄)₂SO₄ on the appearance of the electrochemical impedance spectrum was studied. Equivalent electrical circuits (EEC) were selected and their elements were calculated. It was shown that the spectrum in a pure solution is described by a modified Mansfeld scheme, and in an inhibited solution – by the Randles-Erschler scheme. It was shown that the calculation of EEC elements is in good agreement with the results obtained by ellipsometry.

Aluminum alloys of Al-Mg system have a high corrosion resistance, but scientific researches show that they are characterized by pitting corrosion even under atmospheric conditions. Therefore, various coatings for their protection are used, including coatings obtained by chemical oxidation method. In this paper, studies of chromate-free inhibited IFKhANAL-3 conversion coatings were carried out in the G-4 humidity chamber in combination with electrochemical impedance spectroscopy, conductometric analysis and X-ray spectral microanalysis. This made it possible to identify the factors of the beginning of the corrosion process and, in particular, to show the absence of corrosion inhibitor desorption during testing. It was shown that the addition of 1,2,3-benzotriazole into the converting solution contributes to both an increase in the active resistance (R_f) of the oxide film and a later appearance of the first corrosion damage on the coating in comparison with unmodified coatings. According to the conductometric analysis data, it has been shown that a decrease in the porosity of the coatings is observed during the G-4 humidity chamber tests.

Two commercial migrating corrosion inhibitors (MCIs): MasterProtect 8000 CI, MasterProtect 8500 CI (MBCC Group), and one promising product, MCI-VN, were tested for the protection of steel reinforcement in concrete exposed to seawater along the Khanh Hoa coast (Vietnam) over 6 months. It was found that the alkoxysilane-based impregnations MasterProtect 8000 CI and MasterProtect 8500 CI reduced biofouling on the concrete surface by approximately twofold compared to the control samples without inhibitors. This effect is presumed to be associated with surface hydrophobization. The MCI-VN impregnation reduced biofouling by 30%, while other application methods of MCI showed no significant impact on biofouling. The corrosion state of the reinforcing steel was assessed using electrochemical methods and visual inspection of the steel surface following GOST 31383-2008. A passive state of the steel was observed when MCI-VN was applied as migrating impregnations to the surface of hardened concrete before seawater exposure. When MCI-VN was used as an admixture during concrete preparation, and in the case of MasterProtect 8000 CI and MasterProtect 8500 CI impregnations, electrochemical measurements indicated a passive state. However, visual inspection revealed surface corrosion spots on the reinforcement, classifying the condition as unstable passive. Possible directions for improving regulatory guidelines for assessing the corrosion state of steel reinforcement and corrosion rate have been proposed to distinguish the effectiveness of various corrosion protection measures, including MCIs.

Corrosion inhibitors are used not only as separate protective agents, but also to enhance the anticorrosive properties of paint and conversion coatings on aluminum alloys. The use of superhydrophobic (SHP) coatings is a fairly promising and effective method of protecting metals and alloys, however, the low stability of SHP layers in aqueous media significantly limits their practical application. This article discusses a combined corrosion protection method for aluminum alloy D16 in chloride solutions. The method is based on increasing the stability and preserving the SHP properties of coatings made from stearic and octadecylphosphonic acids by adding small additives of inhibitors (salts of rare-earth metals cerium and yttrium).

At present, tungsten coatings are widely used in the chemical and oil and gas industries, particularly those obtained by chemical vapor deposition (CVD). Under atmospheric conditions, such coatings are subject to corrosion that can destroy a tungsten coating within one year. To address this problem, our article tested an aqueous solution of Catamin AB, which had not previously been applied to tungsten coatings. The article demonstrates the effectiveness of this inhibitor solution at various concentrations and identifies its effective concentration as 0.010% Catamin AB.