Electrochemical, Gravimetric and X-Ray Characterization of Low Carbon Steel Corrosion Rate and Products After Atmospheric Exposure in the Caribbean Area

Abstract

Rust scales of commercially available low carbon steels from Venezuela (A1S1 1010), Mexico and Cuba (A1SI 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 (γ-FeOOH), goethite (α-FeOOH) and akaganeite (ß-FeOOH).Different amounts of lepidocrocite, goethite and akaganeite and the oxide phases hematite (a-Fe 2 0 3 ), magnetite (Fe 3 0 4 ) and maghemite (y-Fe 2 0 4 ) 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. 435Brought to you by | Purdue University Libraries Authenticated Download Date | 5/25/15 4:50 PM

Tropical/non‐tropical marine environments impact on the behaviour of carbon steel and galvanised steel

“…In coastal/industrial areas steel tends to be protected by a Zn coating. However, galvanised steel is strongly affected by chloride presence in the atmosphere and by acid rain, behaviour that has been studied by several researchers, and by wind speed, leading to corrosion–erosion…”