Corrosion of aluminium alloy AlSi7Mg0.3 in artificial sea water with added sodium sulphide. (November 2018) - Šekularac, Gavrilo
Graphical abstract: Highlights: AlSi7Mg0.3 exhibits good corrosion resistance in artificial sea water during 42 days. With 20 ppm Na2 S the resistance is improved due to more crystalline Al oxide layer. At Na2 S ≥ 50 ppm a Al/Mg oxide is formed which is not protective in long term. Properties of oxide layer are dependent on immersion time and Na2 S concentration. Abstract: The corrosion behaviour of aluminium alloy AlSi7Mg0.3 in artificial sea water with added 0, 20, 50 and 100 ppm of Na2 S was investigated over the course of immersion of 42 days. Samples were taken at various times and their electrochemical and microstructural properties characterized. The corrosion current densities in all immersion solutions was very low, in the range of 10 −7 –10 −9 A cm −2 . The structure, composition and protectiveness of the so formed oxide layers were dependent on the Na2 S concentration and immersion time. The presence of low sulphide concentration (<50 ppm) is beneficial for the corrosion protection of AlSi7Mg0.3 alloy.