Аннотация:The study investigated the impact of the octadecylamine to benzotriazole ratio on the effectiveness of their mixture as a chamber inhibitor for steel corrosion, using both corrosion and electrochemical methods. It is established that the anticorrosive after-effect of the mixture depends on the ratio of its components. The inhibitor that contains 75% octadecylamine exhibits the best protective properties. The use of a mixture of octadecylamine and benzotriazole in the chamber treatment of steel is characterized by antagonism of the protective action, but the inhibitor of optimal composition is significantly more effective than the individual components. The antagonism of the protective effect of octadecylamine and benzotriazole may be related to acid-base interactions of these compounds, which results in a decrease in the inhibitor’s vapor pressure. The protective effect of the mixture of octadecylamine and benzotriazole is due to the stabilization of the passive state of the steel, manifested by an increase in the pitting potential and/or anti-pitting basis in chloride-containing electrolytes. The mechanism of action of the studied mixture is “blocking-activation” with a predominance of blocking effects.