Book/Report

FZJ-2018-01184

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Neutron scattering on neutron irradiated steel

Schwahn, D.FZJ* ; Pachur, D.FZJ* ; Schelten, J.FZJ*

1978
Kernforschungsanlage Jülich, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/17165

Report No.: Juel-1543

Abstract: Three pressure vessel steel systems (two base material and one weld material) with a 50 % irradiation induced hardness enhancement were investigated by small angle neutron scattering. All three steel systems were irradiated in the light water moderated research reactor FRJ-1 at a temperature of 150$^\circ$ C. The strongest scattering effect was found for steel A; a pressure vessel containment steel ASTM A 533 B. This system was irradiated with a fluence of 7 10$^{19}$ n/cm$^{2}$ (E > 1 MeV). The annealing behaviour was then investigated after isochronal anneals of 300, 350, 400, and 450$^\circ$ C. Vicker's hardness measurements were made parallel to the neutron scattering experiments. The hardness enhancement of 50 % decreased after the first anneal to 30 % and after thesecond to 18 %. The neutron scattering patterns show a decrease in the number of very small voids having a Guinier radius less than 5 $\mathring{A}$. These voids have annealed, or coagulated into larger voids (R$_{g}$ = 20-25 $\mathring{A}$) with a density of n = 10$^{15}$ cm$^{-3}$. After the third anneal at 400$^\circ$ C, the scattering patterns became, within statistical errors, identical to the scattering pattern of the unirradiated specimen; but a hardness enhancement of 13 % wasmeasured. Prior the anneals, steel B and the weld material showed qualitatively the same scattering pattern as steel A. The annealing behaviour of the weld material, which was irradiated with a neutron fluence of 5 10$^{19}$ n/cm$^{2}$, E > 1 MeV, has not yet been experimentally investigated by neutron scattering. In steel B,which has a vanadium content of 0.2 wt. % and was irradiated with a neutron fluence of 1.5 10$^{19}$ n/cm$^{2}$ (E > 1 MeV), no voids larger than 20 $\mathring{A}$ in diameter were found after annealing (the hardness enhancement decreased from 50 % to 32 % ).

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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