MATERIAL AND APPLIED RESEARCH
IN ŘEŽ NEUTRON PHYSICS LABORATORY
Petr Lukáš et al.
Nuclear Physics Institute, 250 68 Řež
Czech Republic
Reactor LVR 15, NRI Řež p.l.c.
reactor power
10 MW
thermal flux in the core 1.5 1018 ns-1m-2
beam tube
1 1013 ns-1m-2
fuel enrichment
36%
235U
tank type
light water moderated and cooled
Neutron diffraction laboratory, NPI Řež
Bórová záchytová terapie
TKSN-400
HK9
SANS
HK8-a
KSN-2
HK2
víceúčelový
difraktometr
HK8-b
práškový
difraktometr
SPN-100
neutronovod
HK3
HK4
HK6
0
1
2m
Non destructive examination of residual stresses by neutron diffraction
Investigation of stress fields around
weld joints
in collaboration with dr L. Mráz, Welding Research Institute, Bratislava, SK
Stress fields around weld joints
Chemical composition of the WELDOX700 steel (weight %)
C
Si
Mn
P
S
Cr
Ni
Mo
0.144
0.314
1.004
0.006
0.0013
0.372
0.057
0.019
V
Ti
Cu
Al
Nb
B
N
Ca
0. 47
0.015
0.016
0.0043
0.020
0.0015
0.005
0.024
Chemical composition of the weld metal (weight %)
C
Si
Mn
P
S
Cr
Ni
Mo
0.102
-
0.76
-
-
0.27
3.94
0.24
Stress fields around weld joints
150
300
3
10
z
y
x
stress / MPa
75
1000
750
x component
y component
z component
500
250
weld metal corrections
0
-250
-500
2mm
-40
2 mm
-20
0
20
x / mm
Weld deposited pass
y
Plate 15Ch2MFA, 7 mm thickness
welding material Inconel 52
x
-3
2.5
e / 10
z
2.0
ex
1.5
ez
1.0
ey
0.5
0.0
-0.5
-1.0
-1.5
-20
-15
-10
-5
0
5
10
15
20
mm
25
Non destructive examination of residual stresses by neutron diffraction
Residual stresses
in FGM Al2O3/Y-ZrO2 ceramics
in collaboration with Prof. Van der Biest, KU Leuven, Belgium
Residual stresses in FGM Al2O3 / Y- ZrO2 ceramics
Task:
high performance hip replacements
all-ceramic bearings
metal femoral stem
FGM Al2O3/Y-ZrO2 ceramics
alumina:
zirconia:
low wear rate, high hardness
high strength, high toughness
medical applications
 hip prosthesis / all ceramics bearings
 high biocompatibility
 high performance
 compressive stress at working surface
Al2O3 vol. fraction / %
80
0
depth / mm
production
 electrophoretic deposition
 sintering at 1350oC/1hour
 hot isostatic pressing at
1390oC/20 min/140MPa
1
2
3
4
5
90
100
Macroscopic residual stress in the produced ball-head
Lamellar ball-head tested at the neutron diffractometer SPN100
Macroscopic residual stress in the produced ball-head
stress / MPa
300
200
100
0
working
surface
-100
0
2
4
6
8
x / mm
macroscopic residual stress scanned through the produced lamellar ball-head
Non destructive examination of residual stresses by neutron diffraction
Residual stresses
in highly radioactive materials
in collaboration with Dr. A. Hojná, NRI Řež, CZ
Residual stresses in highly radioactive materials
Tasks...
 characterization of reactor construction materials
 radiation damage - material degradation during
service
 monitoring of residual stress level with operation
time and neutron fluence
 component integrity assessment, support of
operation prolongation
ut
ne
be
am
Dedicated shielding container
ne
am
be
ut
ro
n
n
ro
 easy specimen installation
in the hot cells
linear stage
specimen
shielding
shutter,
collimator
linear stage
 remote control of beam
shutters and collimators
 specimen positioning
stepping
motor
Residual stresses in radioactive reactor components
dedicated facility - shielding box, beam shutters, specimen manipulators
MATERIAL AND APPLIED RESEARCH @ NPI ŘEŽ
In situ tests
mechanical properties
Experimental arrangement
~1V, 1500A
neutron diffraction profile
intensity
position
width/shape
phase volume fraction
strain/stress
microstrain
In situ tests @ TKSN400, NPI Řež
Deformation rig
Multiphase materials
• tensile/compressive tests
• hot air heating system 25C-300oC • shape memory alloys
deformation
monochromator
oC
• maximum loading
20 kN • el. current heating up to 1000
• transforming steels
machine
sample
position-sensitive
detector
shielding
beam shutter
thermal neutron
channel
horizontally focusing
monochromator
In situ tests – mechanical properties
TRIP steels
in collaboration with Prof. J. Zrník, West Bohemia University, Pilsen
TRIP steels /transformation induced plasticity/
Task:
construction materials with well balanced strength
and ductility/toughness
Solution:
multiphase materials
duplex steels
bake hardening steels
interstitial free steels
Transformation Induced Plasticity (TRIP) steels
Twinning Induced Plasticity (TWIP) steels
TRIP steels /transformation induced plasticity/
ferrite (~ 60%)
bainite
(~ 20%)
retained
austenite
(~ 20%)
Comparison of the stress/strain behaviours of different types
of structural steels
1. phase: polygonal ferrite
2. phase: bainite
Ferrite-bainite (α) matrix (BCC)
3. phase: retained austenite
Retained Austenite (γ) (FCC)
4. phase: martensite
Strain-Induced Martensite (α’) (BCT)
Application of TRIP multiphase steels in automotive industry
TRIP steels /transformation induced plasticity/

increased plasticity due to phase transformation austenite
martensite taking place in deformed steels simultaneously
with dislocation plasticity
austenite (γ)
(γ)
martensite (α’)
(α’)

significant austenite volume fraction necessary

special concept of alloying combined with appropriate
thermomechanical treatment
TRIP steels
thermomechanical treatment
intercritical annealing
Chemical
composition
(wt.%)
Mn 1.45
bainitic holding
Si 1.9
C 0.19
Cr 0.07
P 0.02
water quenching
S 0.02
Ni 0.02
Al 0.02
Nb 0.003
In situ tests – mechanical properties
Shape memory alloys
in collaboration with Dr. P. Šittner, IoP, Prague
Shape memory alloys
stress
shape memory effect
As
Af
°C
e/
tur
ra
pe
tem
in
a
r
t
s
Inter-phase boundary propagation
Shape memory alloys
Applications:
dust detector
shape memory effect
sensors
actuators
shock absorber
fittings…
MARS Pathfinder
superelasicity
medical tools /e.g. cathetrization, laparoscopy/
high biocompatibility - stents
Shape memory alloys
Tensile stress
Ne
ut
ro

nb
ea
m
D
PS
Axial
polycrystal, T=295K, e =2%
2d hklsin()= n
Evolution of:
stresses?
Temperature
Austenite
strains?
phase
fractions?
Martensite
Axial
in [hkl] oriented
grains
100mm
2.0
2.1
d-spacing [A]
Evaluation of stress-strain response of NiTi
from in-situ neutron diffraction data
Pseudoelasticity of NiTi in
compresion
(111) austenite , axial, compression, T=336K
8
e111 x10 -3
6
1
S 111=73718 MPa
4
Lattice strain,
e111 x10 -3
8
Lattice strain,
Macroscopic stress-strain response of
NiTi can be reconstructed from the
in-situ diffraction data using 3
calibration constants S1, E1 E2
2
0
0
smart composites
100
200
300
400
500
Cal. equations:
1
G=e111*S
Nondestructive in-situ evaluation of
stress-strain responses from embedded
NiTi particles in SMA composites
G
+e
tr
0.01
0.02
0.03
Strain, eG
calculated
1
2
0
117
0
0.0016
1
0.99
G
eG
0
.005
=e111*73 718
1
G
2
measured
No. e111
I111/I0,111
= e111*E
2
111
+ (1-I111/I0,111)*E
= e111*1.597 + (1-I111/I0,111)*0.05
111
/I0,111
1.0
500
Stress, G [MPa]
Ultimate goal:
el
4
600
111
kevlar
- epoxy
Intengral intensity I
SMA
wires
eG=e
111
6
0
0.00
600
Stress, G [MPa]
Cal. constants:
1
1
2
S 111, E 111 and E 111
1
E 111=1.597
2
E 111= 0.05
0.9
0.8
0.7
0.6
400
300
calculated G- e G curve
200
from e111 and I111 using
constants S
100
1
,E
111
1
,E
111
2
111
experimental G- e G curve
0.5
0.000
0.005
0.010
0.015
tr
0.020
el
0.025
Transf. strain e G=eG-e =eG-E1*e111
0
0.00
0.01
0.02
Strain, eG
0.03