Electrochemical, gravimetric and x-ray characterization of low carbon steel corrosion rate and products after atmospheric exposure in the caribbean area

Rust scales of commercially available low carbon steels from Venezuela (AISI 1010), Mexico and Cuba (AISI 1019) were characterised after exposure at two typical atmospheres in the Caribbean region: Merida (rural-urban; RU) and Progreso (marine-coastal; MC). Low carbon steel surfaces rusting in those atmospheres formed mainly the oxyhydroxides lepidocrocite (gamma -FeOOH), goethite (alpha -FeOOH) and akaganeite (beta -FeOOH). Different amounts of lepidocrocite, goethite and akaganeite and the oxide phases hematite (alpha -Fe2O3), magnetite (Fe3O4) and maghemite (gamma -Fe2O4) were found, depending on the deposition rates value of air-borne salinity, time-of-wetness (TOW) and temperature present in every particular test site. The rust scale composition and air pollution are used to explain the corrosion rates and corrosion behaviour of the exposed low carbon steels in the tests sites.