Abstract

This paper presents results of radiation-induced nanoscale microstructural changes measured by Small-Angle Neutron Scattering (SANS) on ASTM-type reactor pressure vessel (RPV) steels. Five different base metals and one weld metal were investigated. The irradiation was performed in a VVER-type power reactor to three different dose levels, maximally 0.14 dpa, at an irradiation temperature of 255°C. The volume content of the micostructural features measured is correlated with the irradiation hardening and embrittlement.

In every case clear radiation-related hardening, embrittlement, and microstrucural effects are proven. Radiation produces nanoscale scattering defects of a radius between 0 < R < 3 nm with the maximum near R = 1 nm. Fluence and chemical composition do not or hardly change the shape of the size distribution but strongly influence the volume fraction. The radiation sensitivity is mainly influenced by the copper content. Copper also increases the A-ratio. There are good correlations between volume fraction of the nanoscale radiation defects and the radiation hardening or embrittlement.

Annealing at 475°C produces almost full recovery of the mechanical properties. However, the original microstructure of the unirradiated state is not completely reproduced.

Issue Section:
Research Papers
Keywords:
microstructure, SANS, radiation hardening, embrittlement

References

1.
Brumovsky
,
M.
,
Gillemot
,
F.
,
Kruykov
,
A.
,
Levit
,
V.
 and
Wallin
,
K.
, “
Phase III of the IAEA Co-ordinated Research Programme Optimizing of Reactor Pressure Vessel Surveillance Programmes and Their Analysis
,” Final Report,
IAEA
,
01
1996
.
2.
Beaven
,
P. A.
,
Frisius
,
F.
,
Kampman
,
R.
, and
Wagner
,
R.
, “
Analysis of Defect Mircostructures in Irradiated Ferritic Alloy
,”
Atomic Transport and Defects in Metals by Neutron Scattering
,
Junit
,
C.
 et al., Eds.,
Berlin
,
1986
, p. 228.
3.
Solt
,
G.
,
Frisius
,
F.
,
Walter
,
W. B.
, and
Bührer
,
W.
, “
SANS and DENS Study of Irradiation Damage in a Reactor Pressure Vessel Material with a Systematic Variation of Irradiation Dose and Heat Treatments
,” ASTM STP 1046,
Packan
,
N. H.
,
Stoller
,
R. E.
, and
Kumar
,
A. S.
, Eds.,
ASTM International
,
West Conshohocken, PA
,
1990
, pp.
154
-
164
.
4.
Buswell
,
J. T.
,
Little
,
E. A.
, and
Sinclair
,
R. N.
, “
An Analysis of Radiation Effects in Model A 533 B Pressure Vessel Steels Containing Copper, Phosphorus and Nickel Additions
,” ASTM STP 1325,
Nanstad
,
R. K.
,
Hamilton
,
M. L.
,
Garner
,
F. A.
, and
Kumar
,
A. S.
, Eds.,
ASTM International
,
West Conshohocken, PA
,
1999
, pp.
30
-
51
.
5.
Wirth
,
B. D.
,
Odette
,
G. R.
,
Pavinich
,
W. A.
,
Lucas
 
G. E.
, and
Spooner
,
S. E.
, “
Small Angle Neutron Scattering Study of Linde 80 RPV Welds
,” ASTM STP 1325,
Nanstad
,
R. K.
 et al., Eds.,
ASTM International
,
West Conshohocken, PA
,
1999
, pp.
102
-
121
.
6.
Carter
,
R. G.
,
Soneda
,
N.
,
Dohi
,
K.
,
Hyck
,
J. M.
,
English
,
G. A.
, and
Server
,
W. L.
, “
Microstructural Characterization of Irradiation-Induced Cu-Enriched Clusters in Reactor Pressure Vessel Steels
,”
J. Nucl. Mater.
 0022-3115 https://doi.org/10.1016/S0022-3115(01)00659-6, Vol.
298
,
2001
, pp.
211
-
224
.
Google Scholar
Crossref
Search ADS
 
7.
Mathon
,
M. H.
,
Barbu
,
A.
,
Dunstetter
,
F.
,
Maury
,
F.
,
Lorenzelli
,
N.
, and
de Novion
,
C. H.
, “
Experimental Study and Modelling of Copper Precipitation under Electron Irradiation in Dilute Fe Cu Binary Alloys
,”
J. Nucl. Mater.
 0022-3115 https://doi.org/10.1016/S0022-3115(97)00010-X, Vol.
245
,
1997
, pp.
224
-
237
.
Google Scholar
Crossref
Search ADS
 
8.
Grosse
,
M.
,
Denner
,
V.
,
Böhmert
,
J.
, and
Mathon
,
M.-H.
, “
Irradiation-Induced Structural Changes in Surveillance Materials of VVER 440-type Weld Metal
,”
J. Nucl. Mater.
 0022-3115, Vol.
277
,
2000
, pp.
280
-
287
.
Google Scholar
Crossref
Search ADS
 
9.
Böhmert
,
J.
,
Gokhman
,
A.
,
Große
,
M.
 and
Ulbricht
,
A.
, “
Nachweis, Interpretation und Bewertung bestrahlungsbedingter Gefügeänderungen in WWER-Reaktor-Druckbehälterstählen
,”
Wissenschaftlich-technischer Bericht
 FZR-381,
Forschungszentrum Rossendorf
, Juni 2003.
10.
Solt
,
G.
,
Frisius
,
F.
,
Waeber
,
W. B.
, and
Tipping
,
P.
, “
Irradiation Induced Precipitation in Model Alloys with Systematic Variation of cu, Ni, and P Content: A Small Angle Scattering Study
,” ASTM STP 1175,
Kumar
,
A. S.
 et al., Eds.,
ASTM International
,
West Conshohocken, PA
,
1993
, p. 444.
11.
Buswell
,
J. T.
,
Phythian
,
W. J.
,
McElroy
,
R. J.
,
Dumbill
,
S.
,
Ray
,
P. H. N.
,
Mace
,
J.
, et al, “
Irradiation-Induced Microstructural Changes, and Hardening Mechanisms, in Model PWR Reactor Pressure Vessel Steels
,”
J. Nucl. Mater.
 0022-3115 https://doi.org/10.1016/0022-3115(95)00026-7, Vol.
225
,
1995
, pp.
196
-
214
.
Google Scholar
Crossref
Search ADS
 
12.
Stephan
,
I.
, “
Bestimmung der Bestrahlungstemperatur im Bestrahlungsprogramm Rheinsberg II
,”
Wissenschaftlich-technische Berichte
, FZR 376,
2003
.
13.
Popp
,
K.
,
Schützler
,
H.-P.
, and
Viehrig
,
H.-W.
, “
Bestrahlungsexperimente zur Untersuchung der Neutronenversprödung von Reaktordruckbehälterstählen
,” Report ZfK-679,
Zentralinstitut für Kernforschung Rossendorf
,
09
1989
.
14.
Barz
,
H.-U.
,
Böhmer
,
B.
,
Konheiser
,
J.
, and
Stephan
,
I.
, “
Ermittlung der Neutronendosis von bestrahlten WWER-Reaktordruckbehältermaterialien
,
Wissenschaftlich-technische Berichte
, FZR-87, Juni 1995.
15.
Strunz
,
P.
,
Saroun
,
J.
,
Keiderling
,
U.
,
Wiedemann
,
A.
, and
Przeniosko
,
R.
, “
General Formula for Determination of Cross-Section from Measured SANS Intensities
,”
J. Appl. Cryst.
, Vol.
33
,
2000
, pp.
829
-
833
.
Google Scholar
Crossref
Search ADS
 
16.
Lindner
,
P.
 and
Zemb
,
T.
, “
Neutron, X-ray and Light: Scattering Methods Applied to Soft Condensed Matter
,”
North-Holland Elseviers
,
Amsterdam
,
2002
.
17.
Große
,
M.
 and
Böhmert
,
J.
, “
Irradiation Damage Structure in VVER-440 Steels after Irradiation at Different Tempertures and Post-Irradiation Annealing
,” ASTM STP 1366,
Hamilton
,
M. L.
, et al, Eds.,
ASTM International
,
West Conshohocken, PA
,
2000
, pp.
323
-
342
.
18.
Kostorz
,
G.
, “
Neutron Scattering
,”
Treatise on Materials Science and Technology
,
H.
 
Herman
, Ed., Vol.
15
,
Academic Press
,
New York
,
1979
.
19.
Glatter
,
O.
, “
Determination of Particle-Size Distribution Functions form Small-Angle-Scattering Data by Means of the Indirect Transformation Method
,”
J. Appl. Cryst.
, Vol.
13
,
1980
, pp.
7
-
11
.
Google Scholar
Crossref
Search ADS
 
20.
Große
,
M.
,
Gokhman
,
A.
, and
Böhmert
,
J.
, “
Dependence of the Ratio Between Magnetic and Nuclear Small Angle Neutron Scattering on the Size of the Heterogeneities
,”
Nucl. Instr. and Meth. in Phys. B
, Vol.
160
,
2000
, pp.
515
-
520
.
Google Scholar
Crossref
Search ADS
 
21.
Böhmert
,
J.
,
Viehrig
,
H.-W.
, and
Ulbricht
,
A.
, “
Correlation Between Irradiation-Induced Changes of Microstructural Parameters and Mechanical Properties for RPV Steels
,”
J. Nucl. Mater.
 0022-3115, Vol.
334
,
2004
, pp.
71
-
78
.
Google Scholar
Crossref
Search ADS
 
22.
Dahl
,
W.
, “
Stahl der Zukunft — Forderungen und Möglichkeiten
,”
Stahl und Eisen
 0340-4803 
101
,
1981
, 967.
23.
Reppich
,
B.
, “
Particle Strengthening,” Materials Science and Technology — A Comprehensive Treatment
,”
Plastic Deformation and Fracture of Materials
, Vol.
6
,
Cahn
,
R. W.
,
Haasen
,
P.
, and
Kramer
,
E. J.
, Eds.,
Weinheim
,
1993
, p. 316.
24.
Russell
,
K. C.
 and
Brown
,
L. M.
, “
A Dispersion Strengthening Model Based on Differing Elastic Moduli Applied to the Iron-Copper System
,”
Acta Met.
, Vol.
20
,
1972
, pp.
969
-
974
.
Google Scholar
Crossref
Search ADS
 
25.
Review of Phosphorus Segregation and Intergranular Embrittlement in Reactor Pressure Vessel Steels
, PWMRP-19,
EPRI
,
Palo Alto
, TR-114783,
2000
.
26.
Odette
,
G. R.
 and
Lucas
,
G. E.
, “
Recent Progress in Understanding Reactor Pressure Vessel Steel Embrittlement
,”
Radiation Effects &amp; Defects in Solids
, Vol.
144
,
1998
, pp.
189
-
231
.
Google Scholar
Crossref
Search ADS
 
27.
Miller
,
M. K.
,
Pareige
,
P.
, and
Burke
,
M. G.
, “
Understanding Pressure Vessel Steels: An Atom Probe Perspective
,”
Materialcharacterization
, Vol.
44
,
2000
, p. 235.
28.
Miller
,
M. K.
,
Russell
,
K. F.
,
Sokolov
,
M. A.
, and
Nanstad
,
R. K.
, “
Atom Probe Tomography Characterization of Radiation-Sensitive KS-01 Weld
,”
J. Nucl. Mater.
 0022-3115, Vol.
320
,
2003
, p. 177.
29.
Pareige
,
P.
 and
Miller
,
M. K.
, “
Characterization of Neutron-Induced Copper-Rich Clusters in Pressure Vessel Steel Weld: An APFIM Study
,”
Appl. Surf. Sc.
,
94/95
,
1996
, p. 370.
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