Inhibitor Protection of Steels in Solutions of Sulfuric Acid under High-Temperature Corrosion (up to 200°C)

Abstract

This article analyzes corrosion of 08Kh18N10T chrome nickel steel in 2 M H₂SO₄ in wide temperature range t = 0–200°C. Under such conditions, corrosion of metal increases with increase in t and at 200°C reaches 9.7 kg/(m² h). It is demonstrated that the composition of substituted triazole, IFKhAN-92 inhibitor and KI (mole ratio 1 : 1), makes it possible to protect this steel in 2 M H₂SO₄ at temperatures up to 140°C, inclusive. A three-component mixture of IFKhAN-92, KI, and hexamethylenetetramine (1 : 1 : 4), is more interesting in this regard, it efficiently inhibits corrosion at t up to 180°C, inclusive, maintaining protection for at least 8 h. The same composition reliably protects low carbon steel, grade 20, in 2 M H₂SO₄ at temperatures up to 180°C, inclusive; moreover, metal corrosion is decelerated in time.