Environmental factors affecting the corrosion behaviour of reinforcing steel. V. Role of chloride and sulphate ions in the corrosion of reinforcing steel in saturated Ca(OH)2 solutions

Haleem, S. M. Abd El; Wanees, S. Abd El; Bahgat, Ahmed

doi:10.1016/j.corsci.2013.04.049

Cited by 64 publications

(20 citation statements)

References 57 publications

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“…Similar studies were reported [5][6][7][8][9][10][11][12][13][14][15][16][17] for mid steel corrosion in chloride contaminated alkaline medium by electrochemical studies and the inhibitors repassivated the steel surface and reduce the pitting corrosion. The present work is also focused on the evaluation of corrosion resistance performance novel inhibitor for mild steel corrosion in chloride contaminated alkaline solution.…”

Section: Introductionsupporting

confidence: 64%

Novel Corrosion Inhibitor for Mild Steel in Simulated Concrete Pore Solution with Chloride Contamination

2015

Chem Sci Trans

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Abstract:The corrosion resistance performance of mild steel in simulated concrete pore solution (pH >12) containing a) 0.5 M sodium Nitrite b) 0.2 M sodium citrate c) 0.4 M sodium benzoate inhibitors in 0.5 M NaCl solution contamination were evaluated by electrochemical studies. The observed inhibition efficiencies were compared with gravimetric method after 30 days of immersion, for inhibited and uninhibited system. The maximum inhibition efficiency of 0.5 M sodium nitrite +0.2 M sodium citrate +0.4 M sodium benzoate mixed inhibitor system was found to be 75%. The inhibition efficiencies for the mixed inhibitor system were compared with control and single inhibitor system. From these study it was found that the role of nitrite ion present in the mixed inhibitor system repassivated the mild steel that drastically reduce the corrosion rate even in presence of high chloride concentration.

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Section: Introductionsupporting

confidence: 64%

Novel Corrosion Inhibitor for Mild Steel in Simulated Concrete Pore Solution with Chloride Contamination

2015

Chem Sci Trans

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“…In the early reports, [28][29][30]32,43 it was demonstrated that the evolution of oxide layer can be detected based on this linear slope, which can reflect the growth kinetics of oxide layer.…”

Section: Resultsmentioning

confidence: 99%

“…[19][20][21][22][23][24] This relationship between OCP and immersion time has been utilized to study the growth kinetics of oxide film formed on the bare metal surface [25][26][27][28][29][30][31] as well as at the coating/metal interface.…”

Section: 6mentioning

confidence: 99%

“…Burstein et al found that the corrosion potential of freshly generated aluminum increased linearly with the logarithm of immersion time during repassivation, which was interpreted to be correlated to the oxide film growth. [19][20][21][22][23][24] This relationship between OCP and immersion time has been utilized to study the growth kinetics of oxide film formed on the bare metal surface [25][26][27][28][29][30][31] as well as at the coating/metal interface. 32 Therefore, in this work the OCP method in combination with XPS and electrochemical impedance spectroscopy (EIS) techniques was applied to comprehensively explore the growth behavior of the EBinduced protective layer and to find out the difference to the growth process occurring without EB.…”

mentioning

confidence: 99%

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Growth Behavior of Initial Product Layer Formed on Mg Alloy Surface Induced by Polyaniline

Luo

Wang

Guo

et al. 2015

J. Electrochem. Soc.

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The quality of the interfacial protective layer induced by polyaniline (PANI) has been claimed to play a crucial role for the enhanced corrosion protection of Mg alloy, but its growth behavior is not well understood. Here some composition, structure and growth kinetics of the protective layer formed at the PANI-emeraldine base (EB) coating/AZ91D Mg alloy interface were investigated to explore the growth mechanism. Upon immersion in 0.5 M NaCl solution, the growing interface layer under EB coating exhibited a fast passivation rate and an increased corrosion resistance, which was largely influenced by ion concentration. XPS depth profiles showed that the EB-induced layer was a mixture of MgO and Mg(OH) 2 , in which no significant bi-layer structure existed and MgO was dominant throughout the bulk film. These observations suggest that the interaction between EB and Mg can promote the faster growth of a stable MgO-rich layer mixed with Mg(OH) 2 probably by solid reaction. Meanwhile less hydration of MgO and dissolution-precipitation reaction occur, thus leading to less Mg(OH) 2 in the outer layer. Magnesium alloys have drawn great attention in automotive and aerospace industry due to their excellent properties such as low density and high specific strength. However, limited corrosion resistance of such alloys has retarded their widespread applications. To improve the corrosion resistance of Mg alloys, numerous coating techniques have been explored, among which organic coating containing corrosion inhibiting pigments is an economical and effective method in industry. One important pigment for Mg alloys is polyaniline (PANI) including emeraldine salt form (ES) and emeraldine base form (EB). 1-6Its highly efficient corrosion-protection performance for Mg alloys has been shown to be competitive to a chromate-pigmented coating. Additionally, self-healing capability was also found on a hybrid solgel/PANI coated Mg alloy upon immersing in Harrison's solution, where no pitting or filiform corrosion occurred around the scratched area while a protective layer was formed.8 Sathiyanarayanan et al. 1 and Wang et al. 8 observed that, after an initial decrease upon immersion in corrosive electrolytes, the complex impedance of PANI coated Mg alloy recovered, which was attributed to the formation of a protective layer. The different chemical composition on the EB-induced protective layer surface was already confirmed by X-ray photoelectron spectroscopy (XPS) in comparison with that formed underneath a varnish coating. 2,6The mechanism of PANI promoting a protective layer formation has been mostly supported by extensive studies in various metal systems.9-14 Nevertheless, few works have been done to understand the protective layer growth behavior. The most intractable issue of how the interaction between PANI and metal induces the protective layer growth still remains unsolved.9 This is attributed primarily to the great difficulty in in-situ investigation on the growth kinetics of interfacial layer formed beneath a coating. Electroche...

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“…Alhozaimy [9] reported that, with the addition of Ca(OH) 2 in a solution of 0.1 M NaOH and 0.175 M KOH, the constitution of passive film changed, and the charge transfer resistance also increased noticeably. Additionally, SO 4 2− may also affect the condition of the steel bar, as indicated by Abd El Hallem and Premlall [10,11], who claimed that SO 4 2− can cause more severe corrosion than Cl − . However, this conclusion was not no experimental evidence supports this point.…”

Section: Introductionmentioning

confidence: 99%

Pore Solution Chemistry of Calcium Sulfoaluminate Cement and Its Effects on Steel Passivation

et al. 2019

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Calcium sulfoaluminate cement (CSA) is a type of low-CO2 binder which has been widely applied in the production of concrete. To investigate the protection capability offered by CSA to keep steel from corrosion, the pore solution chemistry of CSA on steel passivation was investigated in this study. The pore solution of CSA pastes, extracted by an ex situ leaching method, was studied and compared with ordinary Portland cement (OPC). The results show that the alkalinity of the CSA pore solution is not only much lower than that of OPC, but also that a new type of ion, Al(OH)4−, and high concentration of SO42− were detected in the liquid phase of CSA. Based on pore solution chemistry analysis, a simulated pore solution (SPS) system was designed to assess the comprehensive impact of alkalinity and ion composition, featured as properties of CSA, on steel passivation. The results of the corrosion potential evolution highlight the importance of alkalinity in passivation. SO42− can cause depassivation when there is not enough hydroxyl, but Al(OH)4− is able to maintain the alkalinity of the system, enhancing the stability of the passive film.

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Environmental factors affecting the corrosion behaviour of reinforcing steel. V. Role of chloride and sulphate ions in the corrosion of reinforcing steel in saturated Ca(OH)2 solutions

Cited by 64 publications

References 57 publications

Novel Corrosion Inhibitor for Mild Steel in Simulated Concrete Pore Solution with Chloride Contamination

Novel Corrosion Inhibitor for Mild Steel in Simulated Concrete Pore Solution with Chloride Contamination

Growth Behavior of Initial Product Layer Formed on Mg Alloy Surface Induced by Polyaniline

Pore Solution Chemistry of Calcium Sulfoaluminate Cement and Its Effects on Steel Passivation

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