Behavior of hydrogen in stainless steel under irradiation

Abstract

A nondestructive method of the simultaneous analysis of hydrogen and helium in combination with the technique of studying hydrogen migration provides fundamentally new information about the hydrogen behavior in metal-hydrogen systems: about hydrogen migration in metals directly under irradiation and about the mutual effect of implanted hydrogen and helium in constructional materials of nuclear and thermonuclear reactors. The irradiation of metals and alloys with ionizing radiation (ion beams, electrons, and x-ray quanta) causes intense hydrogen migration due to the excitation of electron states from metal-hydrogen bonds whose lifetime is sufficient for hydrogen to leave its regular positions and for nonequilibrium migration. Hydrogen migration over and escape from metals and alloys under the action of electrons and x-ray quanta with an energy below the threshold of defect formation are accompanied by the rearrangement of the defect structure of the material: the annealing of defects of the hydrogen origin due to the annihilation of defects (interstitial atoms and hydrogen-free vacancies). Hydrogen dissolved in metals and alloys reduces the trapping coefficient of the implanted helium, which is due to the formation of fine complexes HV and HV2 and, as a result, to a decrease in the probability of formation of large vacancy complexes which are effective traps for helium.