Eco-friendly corrosion inhibition and scale control in seawater using Foeniculum vulgare and Pimpinella anisum extracts with chemical compounds

This study investigated the corrosion inhibition and scale control properties of both natural extracts and chemical inhibitors for C25 galvanized steel sheets with an 85-μm thick zinc coating steel exposed to seawater. The inhibitors, including Foeniculum vulgare (AF-Sha), Pimpinella anisum (AF-Sim), M640, and Veo, underwent rigorous evaluation through techniques such as Tafel extrapolation, potentiodynamic polarization analysis, concentration factor scale, seawater analysis, X-ray diffraction (XRD), infrared spectroscopy (IR), and conductivity-temperature analysis. Notably, AF-Sha and AF-Sim exhibited outstanding corrosion prevention capabilities, achieving inhibitory efficiencies of 87% and 85%, respectively. Comparative analyses with chemical inhibitors, M640 and Veo, demonstrated promising performance, positioning natural inhibitors as environmentally friendly alternatives. Corrosion rates, inhibition efficiency, and concentration factor scale results provided insights into the inhibitory effectiveness of each compound, with Veo showing superior performance. The study also explored the antiscalant behavior of inhibitors, revealing their ability to prevent corrosion and scale formation. XRD analysis indicated the impact of inhibitors on the crystal structure of scales, while IR spectra provided insights into vibration properties. Conductivity and temperature analyses illustrated the inhibitors' role in reducing ion exchange and gypsum concentration in seawater. These findings suggest that the inhibitors offered robust protection for ferrous metal surfaces and hold significant potential for practical applications. Additionally, our weight loss investigation extends this understanding, demonstrating the practical applicability of corrosion inhibitors like AF-Sha and AF-Sim in real-world scenarios. The presented results contribute significantly to the understanding of galvanized steel corrosion behavior in seawater, offering valuable insights for corrosion engineering applications.