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.