solute clustering in rpv steels under irradiation · · 2013-11-11solute clustering in rpv steels...
TRANSCRIPT
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November 5-8, 2013 Vienna, IAEA
Solute clustering in RPV steels under irradiation
P. Pareige, B. Radiguet, C. Pareige and A. Etienne
Groupe de Physique des Matériaux - UMR CNRS 6634 Université et INSA de Rouen
Saint Etienne du Rouvray, France
Degradation of primary components of pressurised water cooled nuclear reactors:
Current issues and future challenges
RPV steels under irradiation
Neutron irradiation
T ~ 290°C ~ 0.7×1015 m-2.s-1
embritlement
hardening
Origin : Point defects and their clusters, solutes/impurities and their clusters/precipitates, segregations (interfaces, boundaries, …), …
Vessel steel in commercial reactor
Atom Probe Tomography observations
P Si Mn Ni Cu 52×52×135 nm3
Segregation along dislocation
Solute cluster
51×51×96 nm3
P Si Mn Ni Cu Fe
Objects Cluster (Matrix)
Cluster (Dislocation)
Dislocation
P 0,11 ± 0,06 0,76 ± 0,14 0,53 ± 0,12
Si 8,84 ± 0,54 6,92 ± 0,41 6,10 ± 0,40
Mn 5,60 ± 0,44 8,10 ± 0,45 5,85 ± 0,40
Ni 10,76 ± 0,59 9,69 ± 0,48 7,20 ± 0,40
Cu 0,34 ± 0,11 0,40 ± 0,10 0,27 ± 0,08
Radius 1,4 1,5 -
Density (1022m-3)
9.2 ± 1.3 -
H. Huang, B. Radiguet, P. Pareige P. Todeschini C. Chainasse, F. Clémendot
Join Laboratory EDF / CNRS EM2VM
Different vessel steels of commercial reactors
Understanding basic mechanisms
Link microstucture and properties
Vacancy cluster (MFVIC)
y = 0,4x + 1,3
y = 1,3x - 1,3
y = 4,0x - 5,5
y = 3,9x - 4,9
0
6
12
18
24
30
1 2 3 4 5 6 7 8 9
Neutron fluence (1023
n m-2
)
Nu
mb
er
De
ns
ity
(1
022 m
-3)
Steel A (0,03 Cu) Steel B (0,044 Cu)
Steel C (0,07 Cu) Steel D (0,07 Cu)
Linear (Steel A) Linear (Steel B)
Linear (Steel C) Linear (Steel D)
0,5
1
1,5
2
2,5
0 1 2 3 4 5 6 7 8 9
Neutron fluence (1023
n m-2
)
Ra
diu
s (
nm
)
Steel A Steel B
Steell C Steel D
Steel P1 Steel F1
Steel F2 Steel F3
Cu
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November 5-8, 2013 Vienna, IAEA
Vessel steels in commercial and test reactors 5
Steel C P Si Mn Ni Cu Cr Mo V
16MND5
EDF2
(MB) 0.64 0.011 0.43 1.33 0.65 0.056 0.21 0.31 -
EDF3
(WM) 0.25 0.016 0.69 1.43 0.61 0.029 0.021 0.33 0.004
A533B FZD1a
(JPB) 0.92 0.036 0.47 1.31 0.70 0.024 0.18 0.33 0.005
15Kh2MFA AEK1
(BM) 0.74 0.032 0.57 0.54 0.066 0.078 2.82 0.39 0.30
15Kh2NMFAA NRI1
(WM) 0.32 0.011 0.73 0.75 1.59 0.035 1.99 0.40 -
Bulk composition (at.%)
Steel T (°C) Flux
(1012 cm-2·s-1) Fluence
(1019 cm-2)
EDF 3 286 0.15 - 0.2
1.26 / 3.86 / 5.13
EDF 2 1.71 / 5.22 / 6.95
FZD 1a 255 2.2 5.7
AEK 1 272-276°C ~ 2 18.3 / 90.6
NRI 1 288 ~ 30 2.1 / 4.5 / 9.5
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November 5-8, 2013 Vienna, IAEA
EDF samples 6
- Solutes (Mn, Ni, Si , Cu, P) clusters located in the matrix or along dislocation lines (all EDF steels, all fluences)
- Continuous segregation of the same elements along dislocation lines (all EDF steels, all fluences)
Irradiated conditions (EDF-2 and EDF-3 / t1 - t2 - t3)
EDF-2 / t3
One segregation on a loop ?
~1021m-3
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November 5-8, 2013 Vienna, IAEA
FZD-1 samples 7
Irradiated condition (t1)
- P segregation along dislocation lines
P
P Si M
n Ni F
e
41 × 41 × 180 nm3
- Solute clusters
Ni: 6.9±0.3 Mn: 6.8±0.3 Si: 3.0±0.2 P: 0.35±0.1 Cu: 0.07±0.03
N = 24.3±2.0×1022m-3 R = 1.0±0.2 nm
at.%
Intergranular/lath segregation on
boundary with twist component (?)
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November 5-8, 2013 Vienna, IAEA
AEK-1 samples 8
Irradiated conditions (t1 , t3) - Intergranular/lath segregation (t1)
Low angle (?) High angle (?)
θ ~ 2°
Strong influence of GB nature
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November 5-8, 2013 Vienna, IAEA
AEK-1 samples 9
Irradiated conditions (t1 , t3)
- Solute clusters (both fluences)
4,2×17×5,1 nm3
Si P Mn Ni Cu Cr C V Mo Fe
(b) (c) At carbides/ferrite interfaces
In the ferritic matrix
Along dislocation lines
- Continuous segregations (both fluences)
Along dislocation lines
Around dislocation loops
3,7×5,2×3,3 nm3
Along dislocation loops
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November 5-8, 2013 Vienna, IAEA
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Grain / lath boundaries
- Enrichment in C, Si, P, Cr, Mn, Ni, Mo often observed - Evidence of the influence of boundary nature on segregation - No clear evidence of irradiation effects
Solute clusters
- No clear trend with fluence - Flux effect
- Increase with fluence - T effect
Experiment on model alloy: solute behavior?
Fe-1%Mn
• Both alloys prepared by levitation casting
• Homogenization treatment:
1h @ 1000°C
24h @ 840°C
Air quenched
Tem
pera
ture
(°
C)
at.% Mn
Un-irradiated samples
• Random solid solution at nm-scale
• Homogeneous at µm-scale (EPMA analysis)
(0.93±0.03) at.% Mn Fe-Mn 0.5 dpa Dose
0
0,0001
0,0002
0,0003
0,0004
0,0005
0,0006
0,0007
0 500 1000 1500 2000 2500
Depth (nm)
dp
a/s
Homogeneous damage
Fe5+ 10 MeV
T = 400°C
3.11015 m-2.s-1
Needle thickness
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Mn 30.8 ± 2.7
Fe 69.2 ± 2.7
Cluster composition
(at.%)
Tem
pera
ture
(°
C)
at.% Mn
( Fe, Mn)
Bulk composition Mn cluster composition
Clusters have the composition predicted by phase diagram @ 400°C in a super saturated FeMn alloy
FeMn alloy irradiated at 0.5 dpa
Radius (nm) Density (m-3)
1.5 ± 0.2 (4.8 ± 1.4).1022 Fe
Mn
8×8×8 nm3
Formation of Mn rich clusters
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FeMn alloy irradiated at 0.5 dpa
50×50×80 nm3
30×30×150 nm3
Heterogeneous nucleation
Mécanisme interstitiel
I V
Planar defect = point defect sink
V / I flux Mn flux
Local enrichment in Mn
On point defect sink:
CMn > Mn solubility limit
Radiation induced precipitation
of Mn rich phase
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Fe-Cr alloys with different Cr content:
Fe - 2.5 at.% Cr
Fe - 4.9 at.%Cr
Fe - 8.9 at.%Cr
Fe - 12.3 at%Cr
Fe Bal.
Cr 4.61 ± 0.02
Si 0.059 ± 0.002
Ni 0.034 ± 0.002
P 0.013± 0.001
Fe Bal.
Cr 9.16 ± 0.04
Si 0.065 ± 0.003
Ni 0.057 ± 0.003
P 0.013 ± 0.001
Fe Bal.
Cr 11.2 ± 0.04
Si 0.18 ± 0.01
Ni 0.07 ± 0.01
P 0.025 ± 0.002
As measured with Atom-Probe Tomography (APT) – in at.%
Fe Bal.
Cr 2.21 ± 0.01
Si 0.020 ± 0.001
Ni 0.040 ± 0.001
P 0.0090 ± 0.0005
Intra-granular segregation and precipitation in neutron irradiated
Fe-Cr- Si,Ni impurities alloys
Dose : 0.6 dpa
Neutron flux: 9∙1013 n/(cm2 s)
Temperature: 300ºC
BR2 reactor (SCK·CEN) –
MIRE-Cr irradiation program
Calphad
Bonny et al.
a
a + a'
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Fe-5%Cr
33×
33×
13
0n
m3
Fe-9%Cr
Cr enriched clusters
NiSiPCr enriched cluster
Fe-12%Cr
Fe-2.5%Cr
54×
54×
13
7n
m3
Two independent families of clusters are revealed 15
Fe - 9%Cr
30×30×100nm3
Fe - 12%Cr
52×52×230nm3
Cr
Si
Fe - 9%Cr
Twist grain boundary Low angle tilt grain boundary
High angle grain boundaries
Segregation of Si
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▲ résilience KCV à 320°C ; × résilience KCU à 20°C ; ♦ dureté Vickers HV30.
Tservice (285°C – 323°C)
1 mm
40 m
C Cr Ni Si Mo Mn Fe
< 0,2 18 to 21 9 to 12 < 3 1,1 to 1,3 < 1,5 balance
What about solute behavior in Duplex Stainless Steel?
Chemical
composition % at.
Aciers Duplex
Austenite
Ferrite : 10 à 30 %
Décomposition de la ferrite : α → α + α’
α : iron rich ferritic phase
α’ : chromium rich ferritic phase
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Kinetic
Duplex stainless steels (DSS)
2
Ferrite decomposition during ageing
V = 15 5 47 nm3
Fe rich α zones
Cr rich α’ zones (threshold XCr> 26%)
G phase enriched
in Ni, Si, Mn and Mo
(threshold XNi+XSi+XMn
>20%)
Spinodal decomposition + Precipitation
Mechanical properties
Phase transformations
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Duplex stainless steels (DSS)
Spinodal decomposition Precipitation
Synergy between spinodal decomposition and precipitation
Slope = 0.16
Slope = 0.07
Slope = 0.15
Slope = 0.06
3
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November 5-8, 2013 Vienna, IAEA
20 Summary Solutes and Impurities in BCC Iron : segregation and clustering or precipitation With Thermodynamic and/or point defects kinetics Structural evolution in RPV steels is at very beginning in comparison to other materials in other conditions… what will be the evolution of clusters?
1 dpa = 10 highest RPV exposure
Need of experiments/modelling
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Equipment of Excellence
GENESIS
Groupe d'Etude et de Nano-analyses des EffetS
d'IrradiationS
Head of the project
P. Pareige (GPM - Rouen)
C. Pareige, A. Etienne, B. Radiguet
P. Yvon (CEA DEN/DMN - Saclay)
S. Bouffard (CIMAP - Caen)
Partners
Group for Studies and Nanoanalyses of Irradiation Effects
21
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GENESIS: International
Research Plateform
Glasses Ceramics
Non active
Metals Glasses Ceramics
Activity up 200 MBq
Metals
Highly active Hot cells
Caen Rouen Saclay
Fondamental / Applied researches, International Platforme,
Education
22
23
TEM « Station »
Dual Beam – SEM/FIB Atom Probes
EBSD 3D-FIB GIS/ micromanip.
Laser and electric mode High pulse rate High mass resolution
STEM BF / ADF / HAADF EDS / EELS / EFTEM
Double tilt/rotation specimen holder + others
specific holders
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Space
1 nm 1m
Time
1 s
1 ps
40 nm
Atoms
Electrons
Electronic structure
Ab initio (DFT-LDA)
Dislocations Dynamics (DD)
Object or Event Monte Carlo (O or EkMC)
Microstructure
Molecular Dynamic (MD)
Atomic Monte Carlo (AkMC)
10 mm
Dislocations and
irradiation defects
Structure
1mm
1 y
1m
1 c
1 mm
10 m
Crystal Plasticity (CP)
Homogenization
Finite Elements (EF)
Cluster Dynamics
TEM
TAP
SANS
Simulation by
charged particles
Experimental reactors MTR SFR
Mechanical tests
GENESIS
March 3-7, 2013
San Antonio, Texas 24
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GENESIS: International Research Platform
Rouen (open March 2015)
Fundamental / Applied researches, International Platform,
Education
GENESIS – GPM – Rouen Plateform for Nanoanalyses of radioactive materials
And Development of scientific collaboration
Contact : P. Pareige ([email protected])
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