Abstract: The main functional groups of Phyllostachys sulphurea(Carr.)Riviere leaves extract(PSLE) were characterized by Fourier transform infrared (FT-IR) spectroscopy. The inhibition effect of PSLE on the cold-rolled steel (CRS) in 1.0 mol/L HCl solution at 20℃ was studied by methods of weight loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy(EIS)and atomic force microscopy(AFM). Meanwhile, the inhibitive mechanism was proposed from the adsorption viewpoint. The results show that PSLE is a good corrosion inhibitor, and maximum inhibition efficiency is up to 94.2% at concentration 100 mg/L. PSLE exhibits its inhibitive performance via adsorption of functional groups containing N and O atoms on steel surface, and the adsorption of PSLE on CRS surface obeys Langmuir adsorption isotherm. Polarization curves reveal that PSLE behaves as a mixed-type corrosion inhibitor. EIS spectra exhibit one capacitive loop and charge transfer resistance value increases with the increase of inhibitor mass concentration(c). AFM results reveal that PSLE can be adsorbed on steel surface to form a dense protective film.

Key words: Phyllostachys sulphurea(Carr.)Riviere, extract, corrosion inhibitor, hydrochloric acid