time between 50 and 80 nitriding time in the range of 3 to 6 hours discharge time of around 1 0 to 2 0 ms post discharge time between 0 2 and 1 0 ms potential difference in the range of 350 to 400 v and current density between 3 0 and 5 0 ma cm u2212 2 the double potentiostatic electrochemical method was the technique used for the determination of hydrogen permeability in metallic materials however a step was required before the permeation the potentiodynamic polarization test with the aim of defining the cathodic potential or current for hydrogen generation to be used in the permeation test the potentiodynamic polarization test consisted on the application of a potential ramp varying at a rate of for example 600 mv h u2212 between the work electrode that was the sample to be analyzed and the platinum counter electrode displacing it with respect to the open circuit potential the approximately constant open circuit potential measured between the work electrode and the saturated calomel reference electrode to the direction of positive potential values anodic or to the direction of negative potential values cathodic depending on the analysis to be made while the resulting current was monitored during the test a convenient electrolyte was used for example a 0 1 n naoh solution that was bubbled with gas nitrogen the electrochemical reactions that may take place during the application of the potential in the range u2212 2v to 2v are respectively the reduction reaction through which the sample is reduced by gaining electrons cathodic polarization and the oxidation reaction through which the sample is oxidized by loosing electrons anodic polarization the hydrogen permeation parameters were determined from electrochemical hydrogen permeation tests with cathodic charging.