Migration of hydrogen in steel and alloys, stimulated by ionizing radiation

A study is made of the behavior of hydrogen in stainless steel and alloys of titanium and vanadium during exposure of the metals to ionizing radiation (accelerated nitrogen ions, γ-quanta). It is shown that the radiation stimulates intensive migration of hydrogen. The cross section of the accelerated ions is 10−16 cm2. This shows that hydrogen is released from traps as a result of excitation of the electronic subsystem and vibrational degrees of freedom of the hydrogen bonds, with the excitation energy subsequently being transferred to the nuclear subsystem. A phenomenological model is proposed to describe the ionization-accelerated migration of hydrogen in metals. Gamma- and electron-stimulated dissociation of hydrogen-containing bonds inside a solid occur by the Mensell — Homer and Auger mechanisms, as well as by nonadiabatic transition and vibrational-translational exchange. The calculated probability of the migration of hydrogen by these mechanisms is found to agree well with the experimental data.