Effect of Surfactants Upon Corrosion Inhibition of High-Strength Steels and Aluminum Alloys^✫

Research has been conducted on the corrosion inhibition of high-strength steels and aluminum alloys. Several formulations such as borate-nitrite, molybdate-nitrite, and benzoate-nitrate provide good inhibition to these alloys in ordinary tap water. However, when the concentration of chloride ions is high (as is the case of seawater), these formulations, in low concentrations, lose their effectiveness. It has been found that small additions of some surfactants improve the inhibition of borate-nitrite systems tremendously, and these combinations act as excellent inhibitors for high chloride-containing water and other aggressive media such as bilge solutions. Several sodium and barium compounds of phosphonates and sulfonates have been studied. The results of anodic and cathodic polarization and immersion tests on high-strength steels and aluminum alloys are discussed.