Influence of anions on the formation of artificial steel rust particles prepared from acidic aqueous Fe(III) solution

Abstract For simulation of atmospheric corrosion of steels, artificial steel rust particles were prepared in acidic aqueous solutions containing FeCl 3 , Fe(NO 3 ) 3 and Fe 2 (SO 4 ) 3 . A single phase α-FeOOH was formed in only Fe(NO 3 ) 3 system. The β-FeOOH was formed by added Cl − in FeCl 3 –Fe(NO 3 ) 3 system. Adding SO 4 2− in Fe(NO 3 ) 3 , FeCl 3 and a mixture of FeCl 3 –Fe(NO 3 ) 3 solutions turned the products following as α- or β-FeOOH → Schwertmannite (Fe 8 O 8 (OH) 6 (SO 4 )· n H 2 O). Further, increasing the added SO 4 2− suppressed the formation of steel rust particles. Accordingly, the influence of anions on the formation of steel rust particles was to be suggested in order of SO 4 2− ≫ Cl − > NO 3 − .