The cathodic discharge of hydrogen and the diffusion of hydrogen through a cylinder of soft steel are functions of the pH of the electrolytic solution. The maintenance of a previously hydrogenated steel at a temperature of up to 450 degrees C in an acidic or a basic environment shows that the kinetics of disorption of the hydrogen are a function not only of the electrolytic conditions, but also of the temperature and of the length of time for which this temperature is maintained.