Postirradiation recovery of a reactor pressure vessel steel investigated by positron annihilation and microhardness measurements

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Nuclear Technology; (United States)

OSTI ID:5889260

Pareja, R ^[1]; Diego, N De; Cruz, R.M. de la; Del Rio, J ^[2]

---

1. Univ. Carlos III de Madrid, Madrid (Spain)
2. Univ. Complutense, Madrid (Spain)

Positron lifetime and microhardness measurements have been performed on untreated, thermal-aged, neutron-irradiated, and postirradiation-annealed samples of reactor pressure vessel steels with the purpose of investigating the mechanisms of irradiation-induced hardening and recovery of the mechanical properties in these materials. The positron lifetime experiments have not revealed any evidence of the formation of a significant concentration of voids or vacancy clusters in samples irradiated at [approximately]290 C with fluences [le]2.71 [times] 10[sup 23] n/m[sup 2] (E[gt]1 MeV), but they suggest a dislocation annealing induced by the irradiation. Isochronal annealing experiments with neutron-irradiated samples show a simultaneous recovery in their positron lifetime and microhardness at [approximately]340 C. From the microhardness measurements, the yield strength of the irradiated material has been estimated. The results appear to be consistent with a model of hardening due to irradiation-induced dissolution of precipitates with formation of small metastable precipitates after postirradiation aging and recovery induced by the disappearance of these metastable precipitates.

• OSTI ID: 5889260
• Journal Information: Nuclear Technology; (United States), Journal Name: Nuclear Technology; (United States) Vol. 104:1; ISSN 0029-5450; ISSN NUTYBB
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360106 -- Metals & Alloys-- Radiation Effects
665100 -- Nuclear Techniques in Condensed Matter Physics -- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
ANNEALING
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
CONTAINERS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELEMENTARY PARTICLES
FERMIONS
HARDNESS
HEAT TREATMENTS
IRON ALLOYS
IRON BASE ALLOYS
LEPTONS
MATTER
MECHANICAL PROPERTIES
MICROHARDNESS
PHYSICAL RADIATION EFFECTS
POSITRONS
RADIATION EFFECTS
REACTOR VESSELS
STEELS