Corrosion inhibition by ATMP-molybdate-Zn2+ system in low chloride media

Abstract

The effect of amino (trimethylene phosphonic acid), (ATMP), molybdate and Zn2+ on the inhibition of corrosion of mild steel in a neutral aqueous environment containing 60 ppm Cl- has been evaluated by the weight - loss method. It is found that the formulation consisting of 50 ppm ATMP, 300 ppm MoO4 2- and 50 ppm Zn2+ has 96 per cent inhibition efficiency. The nature of the protective film has been analysed by X-ray diffraction technique FTIR and luminescence spectra. It seems that the protective film consists of Fe2(MoO4)3, ZnMoO4, Fe2+-ATMP complex and Zn(OH)2. This film is found to be luminescent.