Structurally selective protection of steel against oxygen corrosion by 1-hydroxyethylidenediphosphonatozincate
A method for protecting steel against oxygen corrosion in water solutions using an inhibitor that selectively reacts with a metal surface in corrosion centers is proposed. 1-hydroxyethylidenediphosphonatozincate, which contains a localized π bond between its phosphorus and oxygen atoms, is used as the inhibitor in combination with magnesium ions at an oxygen concentration of 0.1 to 6.0 mg dm−3 and pH in a water solution of 5.8 to 11.1. A 91–93% degree of protection is achieved at an inhibitor concentration of 6 mg dm−3.