Abstract
The corrosion of mild steel in chloride-rich atmospheres is a highly topical issue for industry and departments of transportation. The formation of the oxyhydroxide akaganeite (β-FeOOH) in this type of atmosphere is associated with a notable acceleration of the steel corrosion process. The scientific literature contains many references to outdoor marine atmospheric tests, but has not yet clarified some issues regarding akaganeite, such as, the environmental conditions for its formation. Research has been performed at thirty atmospheric corrosion stations located at south Florida within 0.1 to 21 miles from the east ocean shore. Conditions in Florida generally led to the formation of akaganeite due to the presence of chlorine in the atmosphere near the ocean. Steel plate samples were exposed for evaluation of crystallographic structures of the corrosion products using the X-ray diffraction (XRD). For this investigation the corrosion products on these samples were analyzed using XRD with a cobalt anode to observe the intensities and peaks related to akaganeite, goethite, lepidocrocite and hematite products. The ratio of akaganeite to the other crystalline iron oxides was calculated from the peak positions corresponding to the respective oxides and intensities. The results show correlations between plate weight loss, distance from the shoreline and akaganeite formation.
