TY - JOUR
T1 - A voltammetric study on the corrosion of prestressed steel in saturated Ca(OH)2 solution containing chloride ions
AU - Henriques, T.
AU - Reguengos, A.
AU - Proença, L.
AU - Pereira, E. V.
AU - Rocha, M. M.
AU - Neto, M. M.M.
AU - Fonseca, I. T.E.
N1 - Funding Information:
Acknowledgements The authors acknowledge the financial support of FCT and FEDER through the programme POCI 2010 (Projects POCI/ECM/55692/2004 and PPCD/ECM/55692/2004). FCT is also acknowledged for the financial support to Centro de Ciências Mo-leculares e Materiais (CCMM) and Unidade de Química Ambiental [528].
PY - 2010/1
Y1 - 2010/1
N2 - An electrochemical study of prestressed steel in saturated Ca(OH) 2 aqueous solutions (pH 12) was carried out in the absence and in the presence of chloride ions, in such a concentration that simulates the composition of seawater. Cyclic voltammetry, linear sweep voltammetry, open circuit potential transients, atomic absorption spectroscopy and scanning electron microscopy coupled to electron diffraction spectroscopy were employed. The linear polarisation curves analysis led to the determination of polarisation resistance, R p, corrosion potential, E corr, corrosion current density, j corr, Tafel slopes, breakdown potential, E b and repassivation potential E repass. A linear dependence of the breakdown potential, E b, on the square root of scan rate was obtained, according to the Point Defect Model (PDM). A crossover characteristic of the nucleation processes was observed in the presence of chloride ions. SEM/EDS studies revealed, as expected, a strong influence of the presence of chloride ions observed in the transpassive and the active regions. In conclusion, chloride ions contribute to enhance the corrosion of steel, most probably due to their adsorption on both the active and the passive electrode surfaces.
AB - An electrochemical study of prestressed steel in saturated Ca(OH) 2 aqueous solutions (pH 12) was carried out in the absence and in the presence of chloride ions, in such a concentration that simulates the composition of seawater. Cyclic voltammetry, linear sweep voltammetry, open circuit potential transients, atomic absorption spectroscopy and scanning electron microscopy coupled to electron diffraction spectroscopy were employed. The linear polarisation curves analysis led to the determination of polarisation resistance, R p, corrosion potential, E corr, corrosion current density, j corr, Tafel slopes, breakdown potential, E b and repassivation potential E repass. A linear dependence of the breakdown potential, E b, on the square root of scan rate was obtained, according to the Point Defect Model (PDM). A crossover characteristic of the nucleation processes was observed in the presence of chloride ions. SEM/EDS studies revealed, as expected, a strong influence of the presence of chloride ions observed in the transpassive and the active regions. In conclusion, chloride ions contribute to enhance the corrosion of steel, most probably due to their adsorption on both the active and the passive electrode surfaces.
KW - Chloride ions
KW - Electrochemical studies
KW - Prestressed steel
KW - Saturated Ca(OH) solutions
UR - http://www.scopus.com/inward/record.url?scp=73349088707&partnerID=8YFLogxK
U2 - 10.1007/s10800-009-9985-0
DO - 10.1007/s10800-009-9985-0
M3 - Article
AN - SCOPUS:73349088707
SN - 0021-891X
VL - 40
SP - 99
EP - 107
JO - Journal of Applied Electrochemistry
JF - Journal of Applied Electrochemistry
IS - 1
ER -