Estudo do comportamento anódico do aço inoxidável ABNT 304 com filme de interferência, em NaCl 3,5% e FeCl3.6H2O 6% p/v.

• Ano de defesa: 1999
• Autor(a) principal: Carlos Roberto de Araujo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Engenharia Metalúrgica e de Minas; Engenharia metalúrgica; Aço Corrosão; Materiais; Corrosão eletrolitica; Corrosão; Aço inoxidável
• Link de acesso: http://hdl.handle.net/1843/BUOS-8DPJUA

ASTM 304 Stainless Steel sheets coated with passive films showing interference colors were subject to electrochemical corrosion tests in order to determine the corrosion resistance behavior regarding anodic protection. The films color varied depending on its thickness. Results were obtained through cyclic polarization and potential versus time curves in aqueous solutions containing 3,5% NaCl and also through total immersion experiments in 6% FeCl3.6H2O solutions at room temperature . Results of film protected samples were compared with film-free samples to verify protection behavior. Potential x time curves were carried on for a minimum time of 3 hours after whichcyclic corrosion tests were performed for each sample. Scanning velocities of 1mVs-1 in non-aerated NaCl solutions were used during these last tests. Immersion experiments consisted of 72 hours exposure of covered and film-free samples to the ferric chloride solution. The relevant experimental results are the following: The film-free steel samples were susceptible to uniform and also a pitting type ofcorrosion in the tested solutions · The corrosion , pitting and protection potentials, as well as current density and corrosion rates were altered with the increment in film thickness Through reverse hysteresis was observed that Increasing the film-thickness oxide film regeneration, in pits sites, was improved · Immersion tests revealed also an increment in pitting corrosion resistance with film thickness increments reducing diameter as well as depth of pits.