Atmospheric corrosion comparison of antirust aluminum exposed to industrial and coastal atmospheres

摘要

>The atmospheric corrosion behavior of antirust aluminum alloys 3A21 and 5A05 in industrial and coastal atmospheres was investigated and compared. Weight loss results, together with corrosion morphology characterization, suggest that the coastal atmosphere is much more corrosive to antirust aluminum than the industrial atmosphere. 5A05 alloy has better localized corrosion resistance than 3A21 alloy, and the corrosion rate shows a decreasing tendency with exposure time. After 3 years of exposure, the antirust aluminum samples only suffer pitting corrosion attack and retain their mechanical properties well. In the two atmospheres, the corrosion products are mainly oxides, aluminum hydroxychloride, aluminum sulfate hydrate, and basic aluminum sulfate. Besides, the atmospheric corrosion mechanism and the corrosion comparison between the two atmospheres were also discussed.