| Comparison of the Protective Performance of PANI/CNT Nanocomposite Coatings Deposited on API 5L Steel by Pulse and Direct Current Electrodeposition in a Chloride Environment |
| کد مقاله : 1359-ICOC |
| نویسندگان |
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زینب مکرمی1، رضا زارعی پور *1، علیرضا امانی قدیم1، رضا محمدی2 1دانشگاه شهید مدنی آذربایجان 2دانشگاه تبریز |
| چکیده مقاله |
| Electrochemical corrosion of API 5L pipeline steels in chloride-containing environments represents a major challenge in the oil and gas industry [1–3]. Conductive polyaniline (PANI) coatings have attracted considerable attention for improving corrosion resistance; however, the inherent porosity and relatively high electrolyte permeability of pristine PANI limit its long-term protective performance [4–6]. Incorporation of carbon nanotubes and the application of electrodeposition as a highly controllable coating technique lead to improved coating structure and enhanced corrosion inhibition efficiency [6–8]. In this study, PANI/CNT nanocomposite coatings were deposited onto API 5L X52 steel using both direct current (DC) and pulse electrodeposition methods. Structural characterization by FT-IR and XRD confirmed the formation of a stable hybrid structure and effective interactions between polyaniline chains and carbon nanotubes [7,9-11]. SEM observations revealed that CNTs acted as conductive bridges within the polymer matrix, filling microvoids and producing a denser and more uniform surface morphology [12,13]. The electrochemical performance of the coatings was evaluated in a 3.5 wt.% NaCl solution using Tafel polarization, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The results demonstrated a significant reduction in corrosion current density and a positive shift in corrosion potential for coated samples compared with bare steel [14,15]. The PANI/CNT nanocomposite coating exhibited a corrosion inhibition efficiency of approximately 79%, which is consistent with previously reported data in the literature [14]. EIS analysis further indicated a substantial increase in charge transfer resistance and larger Nyquist semicircle diameters, reflecting reduced electrolyte penetration and enhanced barrier properties of the coating [16]. A comparison of the deposition methods showed that although both DC and pulse electrodeposition provided acceptable corrosion protection, pulse electrodeposition achieved higher inhibition efficiency within a shorter deposition time. This superiority is attributed to improved control over nucleation and growth processes under pulsed current conditions, resulting in a more compact and homogeneous coating structure [14]. Overall, the results demonstrate that pulse-electrodeposited PANI/CNT nanocomposite coatings represent an efficient, stable, and reliable strategy for protecting API 5L steel in chloride-containing environments, with strong potential for industrial applications |
| کلیدواژه ها |
| PANI/CNT nanocomposite, Pulse electrodeposition, Corrosion inhibition, API 5L steel |
| وضعیت: پذیرفته شده |