A new inhibitor of steel corrosion in sufuric acid

Abstract

A new effective inhibitor of steel corrosion in sulfuric acid, QAS-K1, from the class of quaternary ammonium salts was developed. The effects of the new inhibitor on corrosion of St3 steel in 2 M H2SO4 were studied by gravimetry at 25 and 60°C. In the individual state, QAS-K1 proved to be more effective than the industrial inhibitor catamine AB from a similar class. Anionic (5.0 mmol/l KI, 50.0 mmol/l KBr, and 5.0 mmol/l KCNS) and molecular (0.44 mmol/l diphenylthiourea (DPTU) and 0.60 mmol/l captax) additions increased the efficiency of the new inhibitor. QAS-K1 in mixtures with KI, KBr, DPTU, and captax appeared to be more effective in hindering steel corrosion in H2SO4 than similar mixtures based on catamine AB and tribenzylethanolammonium chloride. Mixtures based on QAS-K1 show a predominantly antagonistic action of the components.