Electrochemical And Surface Analysis of Salvia Officinalis Extract as a Green Corrosion Inhibitor for N80 Carbon Steel in Acidic Media

Abstract

Corrosion of N80 carbon steel in acidic oilfield environments, particularly in 1 M HCl, causes significant material degradation, reducing pipeline integrity and posing operational risks. Although traditional synthetic inhibitors are effective, they often contain toxic chemicals, underscoring the need for eco-friendly alternatives. In this study, the use of Salvia officinalis aqueous extract as a green corrosion inhibitor is explored, offering a sustainable and non-toxic alternative to synthetic inhibitors in corrosive environments.

Tafel polarization, scanning electron microscopy (SEM), and gas chromatography–mass spectrometry (GC–MS) were employed to evaluate the corrosion inhibition performance of Salvia officinalis extract at varying concentrations (50–200 ppm) and temperatures (298 K, 308 K, 318 K). The inhibitor demonstrated up to 94.98% efficiency at 200 ppm and 298 K, with significant reductions in corrosion current density (Icorr) and corrosion rate (CR). SEM analysis revealed smoother steel surfaces, confirming effective corrosion protection. GC–MS identified key active compounds—including phenols, alkaloids, and terpenes—responsible for the extract’s inhibitory effect.

Overall, Salvia officinalis aqueous extract acts as a mixed-type inhibitor, substantially reducing corrosion rates and providing a green, sustainable solution for corrosion prevention in industrial applications, particularly within the petroleum industry. Further research is recommended to enhance its performance at higher temperatures.