Effect of dissolved Si on the corrosion of iron in deaerated and slightly alkaline solutions (pH ≈8.1) at 50?C

Corrosion of iron in deaerated and slightly alkaline buffered solutions was investigated for different Si con-centrations ([Si] varying from approximate to 0 to approximate to 110 mg L-1) over a approximate to 30 days period. In these solutions, iron corrosion led to the formation of a layer consisting of a mixture of Fe oxides and Fe silicates on the metal surface, but also to the precipitation of the same compounds in the medium and to the release of Fe cations. An increase in [Si] promoted the formation of Fe silicates at the expense of Fe oxides, but without increasing the total amount of iron corroded.

Automated summary

The corrosion of iron in deaerated and slightly alkaline buffered solutions was studied for different Si concentrations ([Si] ranging from approximately 0 to approximately 110 mg L-1) over a period of approximately 30 days. It was found that iron corrosion resulted in the formation of a layer consisting of a mixture of Fe oxides and Fe silicates on the metal surface, as well as the precipitation of the same compounds in the solution and the release of Fe cations. Increasing the Si concentration promoted the formation of Fe silicates at the expense of Fe oxides, without increasing the total amount of corroded iron.