TY - JOUR
T1 - Effect of carbon dioxide and temperature on passive film parameters of superduplex stainless steel
AU - Da Costa, Emandro Vieira
AU - Mesquita, Thiago José
AU - Ferreira, Ariane
AU - Nogueira, Ricardo Pereira
AU - Bastos, Ivan Napoleão
PY - 2013/7
Y1 - 2013/7
N2 - 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.
AB - 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.
KW - Carbon dioxide
KW - Electrochemical impedance
KW - Equivalent circuit
KW - Heat-treatments
KW - Superduplex stainless steel
UR - http://www.scopus.com/inward/record.url?scp=84885673434&partnerID=8YFLogxK
U2 - 10.1590/S1516-14392013005000088
DO - 10.1590/S1516-14392013005000088
M3 - Article
AN - SCOPUS:84885673434
SN - 1516-1439
VL - 16
SP - 929
EP - 936
JO - Materials Research
JF - Materials Research
IS - 4
ER -