Black Pine (Pinus nigra) Essential Oil as a Green Corrosion Inhibitor for Carbon Steel

In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for first time as a natural, ecological, and sustainable corrosion inhibitor acid cleaning carbon steel. The extracted by hydrodistillation using Clevenger-type apparatus, analyzed gas chromatography–flame–ionization detection (GC–FID) chromatography–mass spectrometry (GC–MS). most abundant components in were ?-pinene, germacrene D, (E)-cariophyllene, ?-pinene. inhibition efficiency determined electrochemical methods (electrochemical impedance spectroscopy potentiodynamic polarization measurements). results showed that inhibitory increases with time, reaching highest values after 4 h immersion all concentrations. It also shown is mixed-type inhibitor. contact angle measurements confirmed oil, new environmentally safe inhibitor, able to protect steel from 1 M HCl solution.