Publications Scientifiques

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    A novel methodology for monitoring low-temperature corrosion caused by hygroscopic salts using linear polarization resistance
    (Elsevier, 2024) Yahi, Sarah; Bensmaili, Aicha; Lehmusto, Juho; Hupa, Leena; Haddad, Ahmed; Benmohamed, Manel; Vainio, Emil
    A new methodology for monitoring low-temperature corrosion caused by hygroscopic salts was developed and tested with ZnCl2. First, deliquescence and efflorescence points of ZnCl2 were determined by electrochemical impedance spectroscopy and chronoamperometry measurements in the range of 10–35 vol % H2O. Then, low-temperature corrosion was monitored using a probe that combines linear polarization resistance and mass loss measurements. Suitable potential and scan rate for the linear polarization resistance measurements were experimentally determined. The feasibility of the probe was tested by monitoring the corrosiveness of ZnCl2 on P235GH steel under different temperatures (100–180 °C) and water vapor concentrations (15–35 vol %). With the developed corrosion probe, corrosion caused by hygroscopic salts during changes in testing conditions can be monitored and evaluated.
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    Study of the Influence of Metal Surface Quality on the Performance of an Epoxy Coating
    (Elsevier, 2023) Boudieb, Naima; Bounoughaz, Moussa; Hamidouche, Fahim; Ghebache, Zohra
    In the present work, an EC used for steel corrosion protection was characterized by Ec techniques. This study aimed to describe the effect of the steel roughness surface on the performance of EC, through EIS and other methods. The studied metal was a low-strength CS immersed in a 3.5% NaCl solution. The CS surface was obtained by polishing it (metal electrodes) with an abrasive paper of 120, 600 and 1200 mesh. Then, the electrodes were painted with an anti-corrosive EC, which contained Zn3 (PO4)2 as an anti-corrosion agent. The study of the influence of the CS surface Ra and its corrosion behaviour and of the evolution of the protective capacity systems on the EC performance was made by stationary (Ecorr and Tafel plot) and no-stationary Ec techniques (EIS and CA). In order to confirm the detachment and blistering on the coating, the coated CS samples were analyzed by a salt spray in a 7.69 % NaCl solution, with an IT of 15 days. The obtained results showed that the CS surface state directly influenced the coating performance and the Ec parameter values variation, as a function of IT in the NaCl solution. EIS was the most valid Ec method for the studied coatings.
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    Corrosion protection enhancement On aluminum alloy and magnesium alloy by Mo-Ceo2 conversion coating
    (University Mohammed Premier Oujda, 2021) Ziouche, A.; Hammouda, A.; Boucherou, N.; Mokhtari, M.; Hafez, B.; Elmsellem, H.; Abaidia, S.
    In this paper, Mo-CeO2 conversion coating developed to protect Aluminum 2024 alloy and Magnesium AZ31 alloy against corrosion. The cerium oxide incorporated in Molybdenum conversion coating, which considered as a promising alternative to replace chromate compounds. The corrosion efficacy was improving and characterized by polarization curves and EIS measurements. The structural and the microstructural Mo-Ce O2 conversion coating was characterized by AFM, SEM and XRD and the mechanical proprieties was determined by Nano indentation. The presence of molybdenum and oxide of cerium confirmed with good physical and mechanical proprieties. The presence of Ce O2 in the conversion coating had a beneficial effect on the corrosion resistance of the both materials
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    Experimental and theoretical evaluation of the adsorption process of some polyphenols and their corrosion inhibitory properties on mild steel in acidic media
    (Elsevier, 2021) Zerroug, Meriem; Ferkous, Hana; Djellali, Souad; Bouzid, Abderrazak; Mohammed A., Amin; Rezki, Leila; Belakhdar, Amina; Jeon, Byong-Hun; Boulechfar, Chérifa; Benguerba, Yacine
    Polyphenols are now widely acknowledged as safe and biodegradable corrosion inhibitors due to their cost-effectiveness. As a result, this research examines how well polyphenols extracted from Artemisia Herba alba (AHA) prevent mild steel corrosion in a 1 M HCl solution. Inhibitory performance is determined using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and weight loss tests. The shape and chemical content of the mild steel sample surface are evaluated by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) after contact with AHA secondary metabolites in the acidic solution. According to the results of polarization curves, AHA extract works as a mixed-type inhibitor. For all AHA concentrations tested, the Nyquist plots show a semi-circular capacitive loop. On metal surfaces, the Langmuir isotherm regulates inhibitor adsorption. The effectiveness of inhibition is proportional to the extract concentration, reaching 92.9% at 900 ppm. On metal surfaces, the Langmuir isotherm governs inhibitor adsorption. The effectiveness of inhibition is proportional to the extract concentration, reaching 92.9% at 900 ppm. These findings are supported by metal surface experiments, which show that the deposited inhibitor molecules successfully prevent HCl attacks at steel grain boundaries. Finally, quantum chemistry simulations show that dicaffeoylquinic acids, which were found to be the most prevalent AHA extract components, are effective corrosion inhibitors
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    An estimate of a frequency characterizing the electrochemical stability of a gold electrode modified by MHDA thiol in different ways
    (Croatian Chemical Society, 2021) Chaibi, Sarah; Zabat, Mokhtar; Hadjersi, Toufik; Abaidia, Seddik-El-Hak; Zine, Nadia; Yaakoubi, Nourdin; Errachid, Abelhamid
    A theoretical investigation aimed at estimating a characteristic frequency in the medium-low frequency domain in which the impedance response of a given interface measured by electrochemical impedance spectroscopy (EIS) is almost constant, constitutes the basic idea of this work. A theoretical model was subsequently applied to the data resulting from EIS measurements performed on gold electrodes modified by various ways of 16-mercaptohexadecanoic acid (MHDA) thiol functionalization. Analysis of these data revealed a direct relationship between the way the substrate was modified and this characteristic frequency
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    Contribution to the Study of Biotechnological Control Techniques Applied Against Biocorrosion Oil Installations
    (Revista de Chimie SRL, 2021) Khoukhi, Faiza; Nacer-Eddine, Djelali; Kebouche, Salima; Gana, Mohamed Lamine
    The biological activity of oil extracted from green algae has long been known, but evaluation of bimolecular activities contained in this oil on an industrial scale, especially in the oil industry, was the objective of our research project. The first stapes of this study is to extract the essential oil from green algae marine Ulva Lactuca in our region, obtained by extraction/purification method based on hydro distillation and methanol extraction, the work performed at the laboratories of Sonatrach (SH/DTD/AUI/CEM). The second stapes is to evaluate the potential of these algae extracts on microbiologically influenced corrosion. After chemical-physic characterization of two bio naturals products A and B, we test their effectiveness as a bactericide on bacterial corrosion of carbon steel in water contained sulfate reducing bacteria by electrochemical analysis techniques (Open-circuit potential/OCP and Electrochemical Impedance Spectroscopy/EIS).
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    Evaluation efficiency of barium sulfate scale inhibitors by electrochemical impedance spectroscopy
    (2016) Labraoui-Djallal, Karima; Bounoughaz, Moussa
    The electrochemical behaviour of carbon API 5L X70 grade steel electrode towards barium sulfate scaling and scaling inhibitors is investigated in this paper. A study of the carbon steel/injection water interface, with and without inhibitor, was carried out using electrochemical impedance spectroscopy (EIS). The scanning electron microscopy (SEM) and the X-ray diffraction study, in the absence of scale inhibitors, revealed the formation of a thick layer on the surface mainly composed of barium sulfate BaSO4. The barium sulfate scale is formed naturally and evolves with the immersion time. EIS spectra, in uninhibited medium, present three capacitive loop corresponding to transfer charge resistance, deposit resistance and porous resistance. The effectiveness of scale inhibitors used in oil fields pressure maintaining systems is evaluated. The EIS spectra in the presence of the inhibitors show the decrease of the resistances reveal that the scaling inhibitors effect is a tendency to form low amounts of barite solid precipitated on the electrode surface and their inhibiting efficiency increases with concentration rise