Studies on the Inhibition of Corrosion of Mild Steel (Part 2)

Abstract

Corrosion rate of mild steel in phosphoric acid or sulfuric acid were studied using one kind or a mixture of 2 or 3 kinds of nitrogen or sulphur containing organic inhibitors.
The results indicate as follows:
(1) Inhibiting efficiency of the mixture is excellent compared with the case in which one kind of inhibitor is used.
(2) Some inhibitors react as corrosion stimulator when singly used in different kinds of acid, but when they are mixed with one or two other inhibitors they behave as excellent inhibitors.
The cause of these phenomena is considered as the formation of compact films of inhibitor molecules, which are polarized by the effect of electric field and great dielectric constant in solution. Such adsorption film becomes compact, when 2 or 3 kinds of inhibitor molecules are adsorbed.