keywords: Gravimetric, Potentio-dynamic polarization, inhibition efficiency, SEM
The corrosion inhibition performance of Balanitea egyptiaca Del. on Duplex stainless steel (DSS) in 1.0M HCl solution was studied by means of gravimetric measurement and Potentio-dynamic polarization techniques. The inhibition efficiency of the inhibitor increased with increasing concentration. From the gravimetric measurements, the inhibitor shows corrosion inhibition efficiency of 96.1% in 50 mg/L concentration at 333K. Polarization studies showed that corrosion current density decreased in the presence of the inhibitor in comparison to the absence of the inhibitor. It also revealed that, the inhibitor acted as a mixed-type inhibitor with inhibition efficiency of 90.6% in 50 mg/L at 303K. The thermodynamic adsorption and activation parameter were evaluated for corrosion inhibition process. The adsorptions of inhibitor on the steel surface obey Temkin adsorption Isotherm. The surface analysis of uninhibited and inhibited steel sample was performed by scanning electron microscope SEM.