The conditions for the formation of alternative polarity recombination centers of point defects are discussed and their structure is investigated. The centers are shown to be stable point defect-impurity complexes that reverse the polarity while trapping free point defects. Having low mobility and a large trapping radius, these complexes may be efficient point-defect recombination centers. The experimental data are presented on the effect of rare earth elements on the recovery of the electrical resistivity and swelling of low alloyed nickel to support the existence of the recombination centers.

In this paper the results of experimental irradiation studies on mechanical properties, grain boundary deformation, and substructural formation in nickel specimens irradiated in the temperature region of high-temperature radiation embrittlement (HTRE) appearance are presented. Flat nickel specimens with the work surface 0.3 by 3.0 by 10 mm were electron-irradiated to the energy 224 MeV at 100°C to the dose 1 × 1021 e/cm2 (0.2 dpa). The amount of helium in the irradiated specimens was approximately 2.5 × 10-3 at%. Those specimens that had been irradiated to the dose 2.5 × 1018 e/cm2 had the helium content of approximately 10-5 at%. Some specimens were α-particle irradiated until reaching helium concentration of 10-5 at %. The α-particle energy was 30 MeV, generating about 10-8 dpa of damage. The mechanical tension tests were carried out in vacuum 5.0 × 10.0-5 torr (655 Pa) at a rate of 3.0 × 10-3 s-1.

This paper shows that the basic condition for lowering or suppressing swelling is to enhance the annihilation processes and the point defect recombination during recombination. The steel alloy, Cr15Ni35Mo2NbTiAl, is decomposed to exemplify this.

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The paper presents a brief survey of the authors' results in the study of the evolution of dislocation, phase and void structures in austenitic stainless steels under heavy ion irradiation. Stainless steels of the types, Cr18Nil0Ti, Cr16Nil5Mo3Nb. and Cr16NillMo3, in different structural environments were studied. The analysis of structure and composition of unirradiated and irradiated specimens was made using a 100-keV transmission electron microscope (TEM-100) with a spectrometer, “Link Systems 860.”