Compositional variation of hydrogen permeability in ferritic alloys and steels

From a compilation of permeation data of hydrogen in fenitic/martensitic alloys and steels dependences are derived of activation energies and prefactors in Arrhenius-type relations on concentration of constituents. By most constituents the prefactor is reduced and the activation energy is increased compared to pure iron. The permeabilities of ferritic/martensitic stainless steels can be approximated within the scatter of data by a relation which linearly superimposes the individual contributions, while cold working and probably also aging seem to be of minor importance. This relation is used to estimate hydrogen permeabilities of low activation steels for fusion application.