Corrosion and corrosion inhibition by thiourea of bulk nanocrystallized industrial pure iron in dilute HCl solution

The corrosion behaviors of bulk nanocrystallized and coarse grain industrial pure iron (BNIPI & CGIPI) were investigated in 1 mol L-1 HCI at room temperature by means of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curve. Mean-while, the inhibitive effect of thiourea (TU) on the corrosion behaviors were tested. Results indicate that BNIPI is less prone to Occur corrosion than its coarse grain counterpart in blank 1 mol L-1 HCI at room temperature. When CGIPI was immersed for a very short time.. namely, 5 min, an inductive loop appears at different concentrations at the Nyquist plots, but it doesn't appear at those of BNIPI at the same period. A critical concentration of thiourea with the largest R-ct in the complex impedance plane appears for both samples. (c) 2005 Elsevier Ltd. All rights reserved.