Effect of carbon dioxide and temperature on passive film parametersof superduplex stainless steel
AUTOR(ES)
Costa, Emandro Vieira da, Mesquita, Thiago José, Ferreira, Ariane, Nogueira, Ricardo Pereira, Bastos, Ivan Napoleão
FONTE
Mat. Res.
DATA DE PUBLICAÇÃO
11/06/2013
RESUMO
Superduplex stainless steel has been frequently employed in new sites of Brazilian Pre-Salt. In these environments, chloride concentration, temperature and carbon dioxide are normally present in higher levels than those at sea water at room temperature. In these conditions, it is expected that the passive films of stainless steel also show modifications. To better understand such modifications, samples of superduplex stainless steel UNS S32750 were submitted to electrochemical impedance measurements in brine media, at two temperatures and under presence/absence of carbon dioxide. The electrochemical impedance results were initially tested using the Kramers-Kronig transform and subsequently fitted by equivalent circuit employing constant phase elements - CPE. Moreover, to quantify the effect of each factor (temperature, chloride, carbon dioxide and microstructure) on the equivalent circuit, their parameters were tested applying statistical analysis. Significant effect of carbon dioxide and temperature was found on related parameters of passive film for heat-treated samples.
Documentos Relacionados
- Electrochemical Study of the AISI 409 Ferritic Stainless Steel: Passive Film Stability and Pitting Nucleation and Growth
- Sigma Phase in Superduplex Stainless Steel: Formation, Kinetics and Microstructural Path
- Microstructural Transformation in a Root Pass of Superduplex Stainless Steel Multipass Welding
- Effect of temperature on the level of corrosion caused by heavy petroleum on AISI 304 and AISI 444 stainless steel
- Microstructural changes in SAF 2507 superduplex stainless steel produced by thermal cycle