Author(s): GUOLIANG ZHAN | JIANCHENG LUO | SHAOFEI ZHAO | WEISHAN LI
Journal: Journal of Electrochemical Science and Engineering
ISSN 1847-9286
Volume: 3;
Issue: 1;
Start page: 11;
Date: 2013;
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Keywords: Pitting susceptibility | Carbon steel | Phase structure | Polarization curve | Electrochemical impedance spectroscopy | Mott-Schottky
ABSTRACT
The phase structure and the pitting susceptibility of two carbon steels, Q235 and HRB335, used for reinforced concrete, are investigated by phase observation, polarization curve measure-ments, electrochemical impedance spectroscopy, and Mott-Schottky analysis. It is found that Q235 is ferrite and HRB335 is pearlite. Q235 is more susceptible to chloride ions leading to pit-ting than HRB335. The polarization curves show that the breakdown potential of the passive film in saturated Ca(OH)2 solution containing 0.4 M NaCl is 0 V for Q235 and 0.34 V for HRB335. The Mott-Schottky analyses show that passive films formed on Q235 and HRB335 in saturated Ca(OH)2 solution containing chloride ions behave like an n-type semiconductor. The passive film formed on Q235 has a higher donor density, which explains why Q235 is more susceptible to pitting than HRB335.
Journal: Journal of Electrochemical Science and Engineering
ISSN 1847-9286
Volume: 3;
Issue: 1;
Start page: 11;
Date: 2013;
VIEW PDF
DOWNLOAD PDF Original pageKeywords: Pitting susceptibility | Carbon steel | Phase structure | Polarization curve | Electrochemical impedance spectroscopy | Mott-Schottky
ABSTRACT
The phase structure and the pitting susceptibility of two carbon steels, Q235 and HRB335, used for reinforced concrete, are investigated by phase observation, polarization curve measure-ments, electrochemical impedance spectroscopy, and Mott-Schottky analysis. It is found that Q235 is ferrite and HRB335 is pearlite. Q235 is more susceptible to chloride ions leading to pit-ting than HRB335. The polarization curves show that the breakdown potential of the passive film in saturated Ca(OH)2 solution containing 0.4 M NaCl is 0 V for Q235 and 0.34 V for HRB335. The Mott-Schottky analyses show that passive films formed on Q235 and HRB335 in saturated Ca(OH)2 solution containing chloride ions behave like an n-type semiconductor. The passive film formed on Q235 has a higher donor density, which explains why Q235 is more susceptible to pitting than HRB335.
