Evaluation of Steel Corrosion Products in Tropical Climates

Phase variations occurring in corrosion products obtained in steels exposed to different zones of tropical climate in Cuba and Venezuela were determined to establish their relationship to corrosion phenomena. Steel corrosion products were obtained at four test stations in both countries with marine, industrial, and rural characteristics. Phase composition was determined using x-ray diffraction (XRD), infrared (IR) spectroscopy, and Mössbauer spectroscopy. In the rural climate of both countries, the predominant phase was lepidocrocite (γ-FeOOH), which was in agreement with reported corrosion rates. In the marine environments, corrosion products varied in composition. In Adicora, Venezuela, akaganeite (ß-FeOOH) was found, but in Cuba, this phase was nonexistent. Results were discussed in light of the contamination present and meteorological parameters recorded in the test zones.