Formation of magnetite rust particles by reacting iron powder with artificial α-, β- and γ-FeOOH in aqueous media

Abstract To simulate the atmospheric corrosion of steels, magnetite (Fe 3 O 4 ) rust particles were prepared in aqueous media containing iron powder (α-Fe) and artificial α-, β- and γ-FeOOH particles at pH = 6.0 and 50 °C for 24 h. The Fe 3 O 4 formation was not recognized by treating the iron powder with α-FeOOH. When the iron powder treated with β- and γ-FeOOH, these materials were dissolved to generate Fe 3 O 4 and α-FeOOH particles. The amount of formed Fe 3 O 4 particles was in the order of β-FeOOH > γ-FeOOH ≫ α-FeOOH, which was strongly related to the density and solubility of FeOOH.