Inhibition of Mild Steel Corrosion in HCl Solution Using Pipali (Piper longum) Fruit Extract

Corrosion inhibition effect of Piper longum fruit extract on mild steel in 1 M HCl medium has been investigated by weight loss and electrochemical techniques. The effect of temperature, immersion time and acid concentration on mild steel was also studied. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the metal surface. Values of inhibition efficiency calculated from weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy are in good agreement. Polarization curves showed that Piper longum fruit extract behaves as a mixed-type inhibitor in hydrochloric acid. The activation energy as well as other thermodynamic parameters for the inhibition process was calculated. The protective film formed on the metal surface was analyzed by FTIR spectroscopy, dispersive X-ray spectroscopy (EDX) and surface electron microscopy (SEM). The results obtained show that the Piper longum fruit extract could serve as an effective inhibitor of corrosion of mild steel in HCl. The results obtained showed that the fruit extract of Piper longum could serve as an effective inhibitor of the corrosion of mild steel in hydrochloric acid media.