Investigation of the Protective Effectiveness of Nitrogen-Containing Organic Compounds in Protecting Ferrous and Non-Ferrous Metals

Introduction. A promising class of corrosion inhibitors is volatile or vapor-phase ones. They evaporate at ambient temperatures adsorbing on metal surfaces and providing reliable corrosion protection. Volatile corrosion inhibitors penetrate crevices and gaps inaccessible to contact inhibitors, inhibiting corrosion processes along layers of corrosion products. Their use is justified by sealing the protected space, preventing inhibitor evaporation. Currently, there are no low-volatile corrosion inhibitors resistant to temperatures above 80°C, so various packaging materials with low moisture and gas permeability are used. The use of such materials for preserving metal products has revealed several disadvantages: the hygroscopic nature of paper, the degradation of volatile corrosion inhibitors at polymer extrusion temperatures, and the high degree of manual labor required during preservation. Aim of the Study. The study is aimed at developing an effective technology for protecting ferrous and non-ferrous metals using nitrogen-containing organic compounds – volatile corrosion inhibitors. Materials and Methods. Based on the results of electrochemical and accelerated tests, the corrosion rate, protection level, and inhibition coefficient were calculated. St3 steel plates were selected as the samples on which the anticorrosive effect of volatile corrosion inhibitors was tested. Laboratory tests were conducted to determine the protective effectiveness of the resulting inhibitors. The reagents included ethnalolamine, boric acid, mono(aminoethyl)borate, di(aminoethyl)borate, and tri(aminoethyl)borate. The reagent ratio and reaction temperature were varied during the study. Results. A series of volatile corrosion inhibitors were obtained in this study. It was determined that, in electrochemical testing in a 0.1 mol/l sodium chloride solution, the best results were obtained with a composition based on ethanolamine and boric acid in a three-to-one ratio, namely, tri(aminoethyl)borate. The optimal inhibitor concentration on steel surfaces during accelerated testing in an environment with 100% relative humidity is 200 g/m³. As a result of theoretical and experimental studies, there was found the dependence of the traction coefficient of the driving wheels on pneumatic tires during the general case of motion. Discussion and Conclusion. The results obtained have potential for practical application in atmospheric corrosion protection of ferrous and non-ferrous metals. A promising area of application is the protection of steel equipment and electrical protection systems containing non-ferrous metals (copper, brass) using volatile inhibitors in agricultural production, mechanical engineering, and other fields.