Formation and Hazards of Corrosion Product β-FeOOH on Iron Cultural Relics

The crystal structure of β-FeOOH, one of corrosion products of iron cultural relics, as well as its formation process and hazards to iron cultural relics are introduced. β-FeOOH crystal has a tunnel structure, the tunnel usually contains Cl^- ions, and the crystal surface also adsorbs Cl^- ions. β-FeOOH is a key corrosion product of iron cultural relics affected by Cl^- ions, and commonly is formed through hydrolysis and oxidation of FeCl₂ or Fe₂(OH)₃ Cl after excavation. The formation process of β-FeOOH mainly causes rapid deterioration of iron cultural relics, and it will participate in the further corrosion process after formation. The Cl^- ions adsorbed on the surface of crystal will directly induce new corrosion, and the Cl^- ions in the tunnel structure are potential risks in long-term preservation of iron cultural relics. β-FeOOH is a harmful corrosion product to iron cultural relics and should be treated in a targeted manner during the conservation of iron cultural relics.