Original scientific paper

Formation of Rust During the Corrosion of Steel in Water and (NH₄)₂SO₄ Solutions. Part II

Svetozar Musić ; Ruđer Bošković Institute, P O. Box 1016, 41001 Zagreb, Croatia
Đurđica Dragčević ; Ruđer Bošković Institute, P O. Box 1016, 41001 Zagreb, Croatia
Stanko Popović ; Ruđer Bošković Institute, P O. Box 1016, 41001 Zagreb, Croatia
Ilona Czakó-Nagy ; Department of Nuclear Chemistry, Eötvös Loránd University, P. O. Box 32, 1518 Budapest, Hungary

Abstract

Chemical and structural properties of the rust formed by corrosion of steel in water and (NH₄)₂SO₄ solutions at 20 °C for time periods up to 6 months were investigated by X-ray diffraction, Fourier transform IR spectroscopy and 57Fe Mössbauer spectroscopy. Three oxide phases, y-FeOOH (lepidocrocite), Fe304 (magnetite) and a-FeOOH (goethite) were detected in the rust samples. The distribution of these phases in the rust was dependent on the time of corrosion and the concentration of (NH₄)₂SO₄. 57Fe Mössbauer spectroscopy indicated the substoichiometric character of magnetite (Fe3_I04). Magnetite was not observed in the rust generated in 2M (NH₄)₂SO₄ solution. Fourier transfrom IR spectroscopy was particularly useful in the detection of very small amounts of goethite and lepidocrocite in the rust. The strong influence of (NH₄)₂SO₄ electrolyte on the corrosion of steel in aqueous medium was explained as a cumulative effect of two aggresive ions, NH4+ and SO42-.

Keywords

Hrčak ID:

136752

URI

https://hrcak.srce.hr/136752

Publication date:

1.5.1995.

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