Hydrogen transport in 38CrNi3MoN steel covered by thin layer of amorphous carbon

Hydrogen permeation through 38CrNi3MoN steel covered by a thin layer of amorphous carbon has been studied. The hydrogen diffusion coefficient and permeability coefficient through the investigated steel at temperatures from 427 to 713 K have been determined. Obtained data were presented as Arrhenius plot, pre-exponential multipliers and process activation energies were calculated. It is shown that the refinement of investigated membrane microstructures, due to the thermal cycles during covering by amorphous carbon layer, result in increase of hydrogen permeation.