Analysis of protective film formed on surface of mild steel immersed in Chloride ‐ HEDP‐molybdate ‐ Zn2+ environment
Abstract
The inhibition efficiency of the formulation consisting of 1‐hydroxyethane‐1, 1‐diphosphonic acid (HEDP), molybdate and Zn2+ in controlling the corrosion of mild steel in neutral aqueous environment containing 60ppm Cl‐ has been evaluated by the weight‐loss method. The formulation consisting of 50ppm HEDP, 300ppm molybdate and 10ppm Zn2+ has 97 per cent inhibition efficiency. The nature of the protective film has been analysed by using x‐ray diffraction (XRD), FTIR and fluorescence spectra. The protective film is found to be fluorescent and to consist of Fe2+‐HEDP complex, Fe2(MoO4)3 complex and Zn(OH)2. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from the weight‐loss method, polarisation study, XRD, FTIR, fluorescence and atomic absorption spectra.
Keywords
Citation
Rajendran, S., Apparao, B.V. and Palaniswamy, N. (1998), "Analysis of protective film formed on surface of mild steel immersed in Chloride ‐ HEDP‐molybdate ‐ Zn2+ environment", Anti-Corrosion Methods and Materials, Vol. 45 No. 6, pp. 397-402. https://doi.org/10.1108/00035599810236496
Publisher
:MCB UP Ltd
Copyright © 1998, MCB UP Limited