Kinetics of the reaction of hydrogen evolution on steel in inhibited phosphoric acid solutions

The kinetics was studied and the constants of the main stages of hydrogen separation and incorporation into steel in a solution of phosphoric acid containing a mixture of 1,2,4 triazole derivative IFKhAN-92 and KNCS were determined. The addition of IFKhAN-92 + KNCS mixture inhibits the reaction of cathodic reduction of hydrogen and its penetration into steel in H3PO4 solution. The inhibitory effect of this mixture is due to a decrease in the ratio of the hydrogen concentration in the metal phase to the degree of hydrogen filling of the surface. The decrease in the hydrogen concentration in the metal volume by the IFKhAN-92 + KNCS mixture determines the preservation of the plastic properties of steel during corrosion in H3PO4 solutions. The high efficiency of the IFKhAN-92 + KNCS composition, as inhibitors of cathodic reduction of hydrogen and its absorption, is the result of chemisorption of the organic component of the mixture on the surface of steel and the formation of a polymolecular protective layer.