Dynamics of hydrogen accumulation and radiation-stimulated release from steels

Hydrogen accumulation during electrolytic saturation of 12Kh18N10T and 12Kh12M1BFR steels, as well as during thermally and radiation-stimulated hydrogen release from the same materials, was studied. It was shown that there is a critical hydrogen concentration in the sample, which is reached in 50 h for this saturation method (1 M H₂SO₄ electrolyte, current density is 0.5 A/cm²). Initially, hydrogen is trapped at low-temperature (400-500°C) traps of several types in surface layers. At saturation times of 50 h and longer, hydrogen penetrates to high-temperature (800-900°C) traps in the sample bulk. Under electron irradiation of saturated samples, the hydrogen yield nonlinearly increases with electron current density and energy above 40 keV. It was concluded that electronic processes (Auger process and plasmon excitation) play a dominant role in hydrogen diffusion and desorption activation.