Abstract:

In spite of all effects of researchers, up to now there is no understanding of the main radiation phenomena advances, in particular, of the swelling at simultaneously effect of damage dose with generated helium and hydrogen. Imperceptions of this problem is due to absence in the world science society of experimental equipment for investigations under super high damages (~ above 200 dpa). In this paper we carried such irradiation and performed results of the swelling behavior in typical ferritic-martensitic steel EP-450 under different irradiation condition: at high irradiation doses up to 300 dpa, and under dual irradiation with gases (helium or hydrogen). Simulation of radiation damage under environment which is typical for future reactors, as for fusion and accelerator driven system (ADS) the irradiation experiments were conducted using Electrostatic Accelerator with External Injector (ESUVI) at NSC KIPT. Swelling of EP-450 ferritic-martensitic steel were studied under irradiation by Cr ions up to the doses 300 dpa at temperature range 430-550oC. Parameters of swelling, incubation state range; dose zone, where the swelling range reaches the steady state were determined. Irradiation under dual beam modes was conducted using 1.8 MeV Cr+3, 40keV He+, and 20keV H+. It is shown that the behavior of radiation swelling depends on the concentration of helium or hydrogen. Helium and hydrogen have different effects on the kinetics and magnitude of swelling. In the incubation period helium increases void nucleation and raises their concentration. On the steady state period helium reduces swelling steels by reducing the voids size; hydrogen is also effective as helium in acceleration of the swelling beginning, but has less effect on voids nucleation that leads to swelling increase on steady-state period due to uniform rise of voids number density.

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