aging of rpv steel – an atom probe tomography study/lindgren_chalmers... · aging of rpv steel...
TRANSCRIPT
![Page 1: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/1.jpg)
Aging of RPV Steel – An Atom Probe Tomography Study
Kristina Lindgren, PhD student Mattias Thuvander (supervisor)
Division of Materials Microstructure Department of Applied Physics
Chalmers University of Technology
Part of MÅBIL
![Page 2: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/2.jpg)
The project
• What happens on a microstructural scale in the reactor pressure vessel welds after long times in the reactor?
• The RPV is a life limiting component
Long term aging on the atomic scale
![Page 3: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/3.jpg)
Geography
VTT Mechanical testing
Halden Test reactor Irradiation of steel
Chalmers
Ringhals, R4
![Page 4: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/4.jpg)
Reactor Pressure Vessel
Low alloy steel, cladded with stainless steel
https://en.wikipedia.org/wiki/Nuclear_power_plant#/media/File:PressurizedWaterReactor.gif
Welds are the weakest part
Radiation and heat
PWR
At% Low Cu, high Ni!
![Page 5: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/5.jpg)
Neutron Radiation Damage
• Direct matrix damage; vacancies and interstitials
• Segregation to grain boundaries, P
• Precipitation Cu and Mn Ni Si - Cu-rich precipitates,
may contain Mn, Si, Ni - Mn, Si, Ni – “late
blooming effects”?
[Brumovsky 2010]
![Page 6: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/6.jpg)
Ringhals: low Cu high Ni
• Contribution from Ni, Mn, Si rich precipitates after long times
• Not well understood
?
[Brumovsky 2010]
How do the clusters evolve during long term operation??
![Page 7: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/7.jpg)
Atom probe tomography
X, Y
X, Y
Field Evaporation
Position Sensitive Detector
3D Reconstruction
+DC
ToF-MS
![Page 8: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/8.jpg)
Atom probe tomography
• Atomic resolution • Our instrument detectability of 37% • Volumes of ~ 50 x 50 x 200 nm3
• Needle shaped specimen – prepared using FIB/SEM or electropolishing
![Page 9: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/9.jpg)
Focused Ion Beam / Scanning Electron Microscope Image (e or Ga), deposit Pt, mill away material using Ga ions Small volumes of material!
FIB/SEM sample preparation
![Page 10: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/10.jpg)
Specimen
![Page 11: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/11.jpg)
Clusters
~60 years
Orange – Cu atoms
Isoconcentration surfaces Ni+Mn+Si=8.2%
![Page 12: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/12.jpg)
Distribution of elements in clusters
Cu+Ni+Mn+Si
A thin slice of the analysis ~60 years
![Page 13: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/13.jpg)
Proxigram
20 years 30 years 60 years
Increased amount of Si in clusters
Calculated from the isoconcentration surfaces
![Page 14: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/14.jpg)
0
2
4
6
8
10
12
14
0 2 4 6 8
Num
ber d
ensi
ty 1
0^23
clu
ster
s/m
^2
Fluence 10^19 n/cm^2
Number density of clusters
Number density for each run
Average number density
High Cu, Ni AND
No clusters, Ga implantation, boundary
Increasing trend?
#clusters/volume
![Page 15: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/15.jpg)
Size distribution
Cluster algorithm, Ni+Mn, Nmin=18, dmax=0.5 nm
Bimodal distribution? Not only coarsening
~20 years
~30 years
~60 years
![Page 16: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/16.jpg)
P distribution
Purple – P atoms
Isoconcentration surfaces Ni+Mn+Si=8.2% ~60 years
![Page 17: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/17.jpg)
Ongoing work
• More data for statistics • Compare with surveillance material – effect of heat • Evaluating the data!
![Page 18: Aging of RPV Steel – An Atom Probe Tomography Study/Lindgren_Chalmers... · Aging of RPV Steel – An Atom Probe Tomography Study . Kristina Lindgren, PhD student Mattias Thuvander](https://reader030.vdocuments.us/reader030/viewer/2022040905/5e790e57bf7a3d50e539b602/html5/thumbnails/18.jpg)