Abstract: The effect of some organic amines of various structures on the corrosion of low-carbon steel in 2 M HCl, H2SO4, and
H3PO4 (25–95 ℃) was studied. The highest results in slowing down the corrosion of steel allows one to obtain a tertiary diamine
containing more voluminous substituents. Based on this compound, inhibitor compositions have been developed for the protection of
low carbon steel in solutions of mineral acids. These corrosion inhibitors are largely promising for the protection of steel equipment
used in the oil and gas industry in case of potential contact with acid solutions. They protect low-carbon steels in the most popular
mineral acids (HCl, H2SO4, and H3PO4) over a wide temperature range (25–95 ℃), which is extremely important for the industrial
use of acid corrosion inhibitors. The high protective effect of the developed inhibitory compositions upon corrosion of steel in
solutions of mineral acids is confirmed by their effective inhibition of the cathodic and anodic electrode reactions of the metal. In this
case, mixed inhibitors mainly slow down the anode process.
Index terms: low carbon steels, mineral acids, corrosion, corrosion inhibitors, mixed corrosion inhibitors, organic amines, tertiary amines.