Effect of Flow Rate on Corrosion Behavior and Hydrogen Evolution Potential of X65 Steel in 3.5% NaCl Solution

摘要

Effect of flow rate on the cathodic reaction as well as hydrogen evolution potential of X65 steel in3.5% NaCl solution were investigated using Electrochemical impedance spectroscopy (EIS) andpotentiodynamic polarization. It is observed that, compared with static conditions, the charge transferresistance values Rt decreases significantly under the condition of flowing, and the cathodic diffusionlimiting current density increases with the increasing of the flow rate. In addition, the polarizationcurve under static conditions appears a typical hydrogen evolution potential turning point while thepolarization curve under flowing condition does not. The determination of hydrogen evolutionpotential by means of measuring EIS under different cathodic potentials shows that the hydrogenevolution potential of X65 shifts positively to different degrees with the increasing of flow rate.