The effects of hydrogen pre-charging on pitting corrosion resistance and semiconducting nature of passive film formed on two different nitrogen-containing type 316L stainless steel (0.076 and 0.086 wt% N) have been studied. Auger electron spectroscopy (AES) analysis of the alloys after passivation indicated weak nitrogen peak, but the presence of nitrogen and NH3/NH4+ was confirmed by the X-ray photoelectron spectroscopy (XPS) analysis. The results of pitting corrosion in 0.5 M NaCl (pH approximate to 5.7) solution revealed that hydrogen increased the passive current density and significantly reduced the pitting resistance. In 0.3 M H3BO3 + 0.075 M Na2B4O7 center dot 10H(2)O (pH approximate to 8.45) solution, increase in passive current density without affecting the breakdown or transpassive potential was observed for both the alloys. Electrochemical impedance spectroscopy (EIS) measurement after hydrogen pre-charging showed decrease in semi-circle radius of Nyquist plot, and the polarization resistance, R-P associated with the resistance of the passive film. The decrease was significant with increasing hydrogen-charging current density (-50 to -100 mA/cm(2)). The results of the capacitance measurement and Mott-Schottky plots revealed that passive films exhibit n-type and p-type semiconductivity films for both the uncharged and hydrogen charged specimens of the investigated alloys. Doping densities obtained from Mott-Schottky plots increased with hydrogen pre-charging. The overall results indicated that hydrogen pre-charging deteriorated the passive film stability and lowered pitting corrosion resistance. The effects of hydrogen pre-charging on pitting corrosion, passive film and semiconducting properties are discussed in light of the above results. (c) 2009 Elsevier Ltd. All rights reserved.