Stress-induced deformation of metals during fast-neutron irradiation
From European conference on irradiation embrittlement and creep in fuel cladding and core components; London, UK (9 Nov Theoretical models for the deformation of metals subjected simultaneously to external loads and fast-neutron irradiation are discussed. The following models have been analyzed in detail: dislocation climb; climb controlled glide; and nucleation, growth, and unfaulting of dislocation loops. It is shown that the strains produced only by the climb of dislocations are equal to the isotropic swelling strains plus the thermal creep strains due to climb of dislocations. No irradiation-induced creep results from the climb of dislocations or growth of loops. The climb controlled glide of dislocations is a viable irradiation creep mechanism for low fluences at all temperatures or for all fluences at high temperatures. At low temperatures the hardening occurs by the elastic interaction of loops and dislocations. It is shown that the climb controlled glide of dislocations through the loop structure can explain the transient irradiation creep behavior. Steady-state creep, however, at low temperatures is explained by the stressaffected nucleation of dislocation loops. Comparison of the theoretical prediction with the experimental results suggests that stress not only influences the orientation of the loop nuclei but also enhances the interstitial loop nucleation and reduces the vacancy- loop nucleation. In addition, various mechanisms are discussed briefly for the effects of stress on the irradiationinduced swelling of metals. Since irradiation creep and swelling both occur by partial segregation of vacancies and interstitials it was concluded that the two phenomena are closely related. (auth)
- Research Organization:
- Westinghouse Electric Corp., Madison, Pa. (USA). Advanced Reactors Div.
- DOE Contract Number:
- AT(11-1)-3045
- NSA Number:
- NSA-29-024801
- OSTI ID:
- 4334464
- Report Number(s):
- CONF-721115--7
- Country of Publication:
- United States
- Language:
- English
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