Influence of Magnesium Ions in the Seawater Environment on the Improvement of the Corrosion Resistance of Low-Chromium-Alloy Steel

This study examined the synergic effect of alloying the element Cr and the environmental element Mg(2+) ions on the corrosion property of a low-alloy steel in seawater at 60 °C, by means of electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) tests and weight-loss tests. The Mg(2+) ions in seawater played an important role in lowering the electron transfer of the rust layer in the Cr-containing steel. The corrosion resistance of the Cr-containing steel is superior to that of blank steel in Mg(2+) ions containing seawater. XPS and XRD results indicated that the formation of MgFe(2)O(4) and a mixed layer (Cr oxide + FeCr(2)O(4) + MgCr(2)O(4)) improved the corrosion resistance of the low-alloy steel in the seawater.