Effect of surface nanocrystallization on the electrochemical hydrogen evolution behavior of IF steel

Cathodic polarization curve and electrochemical impedance spectroscopy in 30% NaOH solution were utilized to investigate the hydrogen evolution (HE) behavior of interstitial free (IF) steel surface nanocrystallized (SNC) via ultrasonic particulate peening. The surface morphology and grain size of the steel were analyzed by scanning electronic microscope and X-ray diffraction. It was found that the IF steel treated by SNC and SNC + 1% rolling got reductions of 200 mV and 300 mV in HE over-potentials, respectively. Their real surface areas are enlarged by about 20 times and the hydrogen evolution reaction activation free energies are about 50% of the original IF steels's activation free energy.