Study of an alternative phosphate sealer for replacement of hexavalent chromium

Autor(es)

Banczek, E. P. ^[1] ; Terada, M. ^[2] ; Rodrigues, P. R. P. ^[1] ; Costa, I. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Estadual Centro Oeste, Dept Quim Unictr, BR-85040080 Guarapuava, PR - Brazil

^[2] Univ Sao Paulo, Escola Politecn, Dept Met & Mat Engn, BR-05508030 Sao Paulo - Brazil

^[3] IPEN CNEN SP, Ctr Ciencia & Tecnol Mat, BR-05508030 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SURFACE & COATINGS TECHNOLOGY; v. 205, n. 7, p. 2503-2510, 2010.
• Citações Web of Science: 6

Resumo

This study evaluates the possibility of replacing the hexavalent chromium passivation treatment used as a sealer after phosphating of carbon steel (SAE 1010) by a treatment with niobium ammonium oxalate (Ox). Samples of carbon steel (SAE 1010) after being phosphated in a zinc phosphate bath (PZn + Ni) were immersed in solution of niobium ammonium oxalate (250 mg L-1 of Nb) either at pH 3.0 or pH 8.0. A passivation treatment with a solution with CrO3 (200 mg L-1 of Cr6+) was also used for reference. The corrosion resistance of the phosphated samples after passivation treatments was analyzed in a NaCl 0.5 mol L-1 solution using electrochemical impedance spectroscopy (EIS) and anodic polarization curves. Salt spray tests were also performed to evaluate their corrosion resistance. The results showed that the highest corrosion resistance was obtained by passivation in a solution with (250 mg L-1 of Nb) at pH 8.0. (C) 2010 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 07/51363-5 - Avaliacao de aditivos alternativos ao niquel para banhos de fosfato de zinco utilizados na fosfatizacao de aco carbono.
• Beneficiário: Isolda Costa
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/54836-4 - Correlação entre microestrutura e resistência à corrosão nas ligas ODS Eurofer para reatores de fusão nuclear
• Beneficiário: Maysa Terada
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado