Synergistic Corrosion Inhibition of Medium Carbon Steel Using Grapeseed and Palm Kernel Essential Oil Extracts in NaCl Environment

Department of Mechanical Engineering, Covenant University, Ogun State, Nigeria

Abstract

Corrosion in industrial applications significantly affects carbon steel, a widely used but corrosion-prone material. This study examines the inhibition performance of grapeseed (GS) and palm kernel (PK) essential oil extracts, along with their combination (GSPK), on medium carbon steel (MCS) in a NaCl environment. Corrosion rate and inhibition efficiency were analyzed at extract concentrations of 0.5% to 3.5% over 264 hours. Without inhibitors, the MCS corrosion rate increased from 0.034 mm/y to 0.055 mm/y due to Clion-induced electrochemical reactions. With inhibitors, the corrosion rate decreased notably, with peak inhibition efficiencies at 3.5% concentration: 90.6% (GS), 92.5% (PK), and 88.7% (GSPK). GS exhibited the most stable inhibition, PK showed gradual improvement, and GSPK displayed fluctuations. Statistical analyses, including ANOVA and regression modeling, confirmed significant correlations between extract concentration, exposure time, and inhibition efficiency. These findings highlight the potential of “biologically derived corrosion inhibitors as sustainable corrosion control solutions, enhancing industrial sustainability and environmental safet