Análise dos estágios iniciais da corrosão do aço-carbono e aço patinável expostos em ambiente marinho-industrial e rural

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

ASTM A36 and ASTM A242 steel samples were exposed for 4 months in marineindustrial and rural sites. The meteorological conditions and the SO2, SO4 -2, Cl- and TSP concentrations were evaluated during all the research period. The corrosion products were characterized by x-ray difractometry and Mössbauer spectroscopy. The samples exposed in rural environment showed g-FeOOH and g-Fe2O3, while samples exposed in marine-industrial environment showed a-FeOOH and g-FeOOH. Corrosion rates and thickness losses were determined through mass loss essay. ASTM A36 mass loss was larger than ASTM A242 mass loss. Simple linear regressions were performed for mass loss in function of time and multiple linear regressions were performed in order to produce equations for corrosion rates in function of environmental parameters for ASTM A36 and ASTM A242 steels. It was verified that Cl- and SO4 -2 ions were the more influent factors in corrosion of samples exposed in marine- industrial environment. There must be a competitive adsortion process between Cl- and SO4 -2 ions for marineindustrial environment. For samples exposed in rural environment, it was verified that pollutants probably dont influence linearly their corrosion rates. Therefore, meteorological factors as humidity must be more important to corrosion of steel exposed in this environment.

ASSUNTO(S)

corrosão poluentes espectroscopia aço mössbauer ciência dos materiais engenharia mecanica

ACESSO AO ARTIGO

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