Influence of medium ph on the hydrogen permeability of passivating films and the corrosion crack growth rate in 40KhN steel

This paper investigates the interrelationship between medium pH and the hydrogen permeability of the passive layer on the electrolyte-metal interface and also of their influence on the corrosion crack growth rate in high strength low-ductility 40KhN steel. Aqueous NaC1 solutions of different concentrations were used as the corrosive medium in the experiments. It is established that the medium pH not only plays a definite role in the process of formation of hydrogen but also changes the hydrogen permeability of the passive films at the medium-metal interface.