Influence of injected helium concentration and irradiation temperature on gaseous porosity evolution in BCC and FCC steels

Full text of publication follows: The peculiarities of gaseous porosity formation have been investigated in the austenitic steels Cr18Ni10Ti and ChS-68, and ferritic-martensitic steel EP-900 irradiated by 40-keV He+-ions up to fluences of 1018 and 1019 m-2 at temperatures of 570 and 690 K. It is found that the there is no formation of bubbles at 570 K for both the fluences, but at 690 K there is formation of well resolvable in TEM bubbles in ferritic-martensitic steel. It is shown that in steel Cr18Ni10Ti exposed to normalizing anneal, the bubble evolution is delayed at a low helium concentration, and an excess of defects in steel ChS-68 promotes the formation of bubbles at a fluence as low as 1018 m-2 and an irradiation temperature of 690 K. (authors)