Influence of anions on the formation and structure of artificial zinc rusts

Abstract To simulate the atmospheric corrosion of steels galvanized with Zn under different conditions, artificial zinc rusts of basic zinc salt (BZS) were prepared by hydrolyzing ZnO particles in aqueous solutions including ZnCl 2 , ZnSO 4 and Zn(NO 3 ) 2 . In ZnCl 2 –ZnSO 4 , ZnSO 4 –Zn(NO 3 ) 2 and ZnCl 2 –Zn(NO 3 ) 2 –ZnSO 4 systems, zinc hydroxysulfate (Zn 4 (OH) 6 (SO 4 )· n H 2 O) was formed while zinc hydroxychloride (Zn 5 (OH) 8 Cl 2 ·H 2 O) was generated in ZnCl 2 –Zn(NO 3 ) 2 system. Zinc hydroxynitrate (Zn 5 (OH) 8 (NO 3 ) 2 ·2H 2 O) was yielded in only Zn(NO 3 ) 2 system. All the formed artificial zinc rusts were hexagonal plate particles. These results suggest that SO x is the most effective corrosive gas on the formation of BZS rusts on galvanized steel.