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Evaluation of localised corrosion behaviour of super austenitic stainless steels using dynamic electrochemical impedance spectroscopy
Author(s) -
Nagarajan S.,
Tamilselvi S.,
Rajendran N.
Publication year - 2007
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.200503973
Subject(s) - dielectric spectroscopy , nyquist plot , corrosion , materials science , alloy , dissolution , electrical impedance , austenite , metallurgy , electrochemistry , analytical chemistry (journal) , microstructure , chemistry , electrode , electrical engineering , chromatography , engineering
Potentiodynamic polarisation and dynamic electrochemical impedance spectroscopic (DEIS) measurements were carried out in natural sea water on type 316L SS, Alloy 926 and Alloy 31. In order to study the localised corrosion resistance, the dynamic electrochemical impedance spectroscopy measurements were performed in a wide range of potentials covering corrosion potential (OCP or E corr ), passive region, break down region and dissolution region. In this report we have shown that the impedance measurement in potentiodynamic condition allows simultaneous investigation of the changes in the passive layer structure and the ion transport process that occurs through the passive layer. The Nyquist plots were fitted using nonlinear least square (NLLS) method for different potential regions. Finally, the experimental results of polaraisation data were found in good agreement with that of DEIS measurement.