corrosion resistance of al-fe-alloy-coated steel, refractory ......result- refractory metals c o2 =...
TRANSCRIPT
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Minoru Takahashi, Abu Khalid Rivai
Research Laboratory for Nuclear ReactorsTokyo Institute of Technology, Japan
Corrosion Resistance of Al-Fe-alloy-coated Steel,
Refractory Metals and Ceramics in Lead-Bismuth at 700ºC
Corrosion Resistance of Al-Fe-alloy-coated Steel,
Refractory Metals and Ceramics in Lead-Bismuth at 700ºC
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Motivation
Structural materials: 400-550 ºCHigh Cr F-M steels (with Si and Al addition)
Cladding materials: 650-700 ºCHigh Cr F-M steels with Si and Al additionsAl-Fe-Surface coated steelsRefractory metalsCeramics
High boiling points of lead alloys can provide high temperature reactor with thermal efficiency higher than 40%.
Candidate materials compatible with lead alloys
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Materials CompatibilityAustenitic steels SS316, SS316FR poor
Steels12Cr steels10-18Cr steels with Si and Al addition
SUH3, NTK04L, Recloy10, SUS430 excellent
Al-alloyed surface (GESA) ODS locally goodRefractory metalsCeramics
W, Mo excellent
HCM12A, etc. good
SiC, Si3N4 excellent
Flowing fluid: Pb-Bi eutectic (LBE)Temperature: 550°CVelocity: 1 or 2 m/sExposure time: 1,000 or 2,000 hrsOxygen concentration: 10-8-10-6 (wt%)
Results of previous corrosion tests
4
Purpose
To investigate the compatibility of materials in stirred LBE at 700 ºC
Steels: High Cr steels, Al-Fe-coated onesCeramics: SiC, Ti3SiC2,
SiC/SiC compositesRefractory metals: W, Mo, Nb
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Test apparatus
P
Digital
F
FV1
V2V3
V4
V5
V8
V10
V6
V7
ElectrometerPP
Digital Controller
FF
FFV1
V2V3
V4
V5
V8
V10
V6
V7
Steam Generator
Moistureatmosphere
Exhaust NozzleInjection Nozzle
Ar + H2
Ar
Specimens
6Specimens
Thermocouple
Alumina Crucible
Oxygen Sensor
LBE
Mo Wire
Injection Nozzle
72 mm
100 mm
Corrosion test section
Ceramic
340 mm
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Experimental conditions
Run No. 1 No. 2Materials STBA26,
SiC/SiCcomposites
NTK04L, SUS316FR Recloy10, SUS430, Al-Fe-
coated steel, W, Mo, Nb, SiC, Ti3SiC2
Oxygen concentration (wt%) ~6.8x10-7 ~5x10-6
Injection Gas Ar Ar+H2 (3%) and Ar
Type of Sensor Y2O3-ZrO2
Temperature of LBE (ºC) 700Immersion time (hr) 1,000
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Al-Fe coating (thickness: 21.45µm)
Target (Al) Target (SUS304)
Bulk Material
Moving Magnet Source
e- e-kinetic energy
Ar Ar
Unbalanced Magnetron Sputtering(UBMS)
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Unbalanced Magnetron Sputtering(UBMS)
Specimens
10
Oxygen concentration
200 300 400 500 600 700-350
-300
-250
-200
-150
-100
0.01
0.1
(1/3)Cr 2 O 3
(1/4)Fe 3 O 4
H 2 O
NiO
PbO
(1/3)Bi 2 O 3
1.0
1010-8
10-7
10-6
10-5
10-4
10-3
P H2 /P H2O
C (wt.%)
Oxygen potential in injected gas (1/2)RT ln P O2
ΔG
o,
Δ
GO
x,
(1/2
)RT
lnP
O2
(kJ/
g at
mO
)
Temperature (°C)
Oxygen potential in Pb-Bi Δ G Ox
Oxygen potentials of oxides Δ G o
5 x 10-6 wt%6.8 x 10-7 wt%
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CO2 = 5 x 10-6 wt.% (NTK04L, SUS316FR)CO2 = 6.8 x 10-7 wt.% (STBA26) 700ºC
High Cr Steels (NTK04L, STBA26, SUS316FR)
resin
40µm
Pb-Bi Penetration NTK04L matrix
Cr
Si
Fe
Pb
Bi
O
resin
40µm
Pb-Bi Penetration NTK04L matrix
Cr
Si
Fe
Pb
Bi
O
Cr
Si
Fe
Pb
Bi
O
6.12 µm
resin
6.12 µm
100µm
Pb-Bi Penetration STBA26 matrix
Cr
Si
Fe
Pb
Bi
O
Cr
Si
Fe
Pb
Bi
O
6.12 µm
resin
6.12 µm
100µm
Pb-Bi Penetration STBA26 matrix
Cr
Si
Fe
Pb
Bi
O
Cr
Si
Fe
Pb
Bi
O
resin
30µm
Pb-Bi Penetration SUS316FR matrix
Fe
Cr
Ni
Pb
Bi
O
resin
30µm
Pb-Bi Penetration SUS316FR matrix
Fe
Cr
Ni
Pb
Bi
O
NTK04L 17.8Cr-0.4Si-3.34Al
STBA26 9Cr-0.2Si
SUS316FR 18Cr-12Ni
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CO2 = 5 x 10-6 wt%, 700ºC
High Cr Steels (Recloy10 17.7Cr-1Si-0.9Al)
resin
Oxide layer
SUS430 matrix
5.29 µm
3.77 µm
6.94 µm
resin
Oxide layer
SUS430 matrix
5.29 µm
3.77 µm
6.94 µm
5.29 µm
3.77 µm
6.94 µm
resin oxide layer
steel
Cr
resin oxide layer
steel
Cr Si
resin oxide layer
steel
Si
resin oxide layer
steel
10µm10µm
resin oxide layer
steel
Al
resin oxide layer
steel
Al10µm10µm 10µm10µm
6.12 µm
resin
6.12 µm
100µm
Pb-Bi Penetration SUS430 matrix
Cr
Si
Fe
Pb
Bi
Al
6.12 µm
resin
6.12 µm
100µm
Pb-Bi Penetration SUS430 matrix
Cr
Si
Fe
Pb
Bi
Al
Cr
Si
Fe
Pb
Bi
Al
1000h
500h
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CO2 = 5 x 10-6 wt%, 700ºC
Bi
High Cr Steels (SUS430 18Cr-0.75Si)
resin
Oxide layer
SUS430 matrix
5.29 µm
6.12 µm
40.0 µm
resin
Oxide layer
SUS430 matrix
5.29 µm
6.12 µm
40.0 µm
5.29 µm
6.12 µm
40.0 µm
resin oxide layer
steel
Cr
resin oxide layer
steel
Cr
10µm
resin oxide layer
steel
Si
resin oxide layer
steel
Si
6.12 µm
resin
6.12 µm
30µm
Pb-Bi Penetration SUS430 matrix
Cr
Si
Fe
Pb
Bi
O
Cr
Si
Fe
Pb
Bi
O
10µm
1000h
500h
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Al-Fe-coated (STBA26)
resin
oxide layer STBA26
40 µm
～20 µm
sputtered layer
gold coating
～3.7 µm
resinoxide layer STBA26
40 µm
～20 µm
sputtered layer
gold coating
Fe
Ni
Pb
Bi
Cr
SiAl
O
resinoxide layer STBA26
40 µm
～20 µm
sputtered layer
gold coating
Fe
Ni
Pb
Bi
Cr
SiAl
O
CO2 = 6.8 x 10-7 wt.%, 700ºC
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Ceramics1000 hours, CO2 = 5 x 10-6 wt.% (SiC, Ti3SiC2)CO2 = 6.8 x 10-7 wt.% (SiC/SiC composite) , 700ºC
SiC
Ti3SiC2
SiC/SiCcomposite
resin SiC Matrix resin SiC Matrixgold coating
40 µm100 µm
resin SiC Matrix resin SiC Matrixgold coating
40 µm100 µm
resin Ti3SiC2 Matrix resingold coating
30 µm100 µm
Ti3SiC2 Matrixresin Ti3SiC2 Matrix resingold coating
30 µm100 µm
Ti3SiC2 Matrix
5.29 µm
resin
5.29 µm 20.8 µm
33.7 µm
resin
50µm
20.8µm
crackSiC/SiCComposite
33.7µm
100µm
SiC/SiCComposite
5.29 µm
resin
5.29 µm 20.8 µm
33.7 µm
resin
50µm
20.8µm
crackSiC/SiCComposite
33.7µm
100µm
SiC/SiCComposite
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Weight Change of Ceramics
-80-70-60-50-40-30-20-10
0102030
SiC Ti3SiC2
Specimens
Wei
ght l
oss (
g/m
2)
SiC/SiCComposite
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Result- Refractory Metals
CO2 = 5 x 10-6 wt.%, 700ºC
resin W Matrix resin W Matrix
gold coating
20 µm50 µm
resin W Matrix resin W Matrix
gold coating
20 µm50 µm
resin Mo Matrix resin Mo Matrix
gold coating
20 µm50 µm
resin Mo Matrix resin Mo Matrix
gold coating
20 µm50 µm
resin Nb Matrixadhered Pb-Bi
Pb-Bi penetration
Nb Matrixadhered Pb-Bi
Pb-Bi penetration
40 µm100 µm
resin Nb Matrixadhered Pb-Bi
Pb-Bi penetration
Nb Matrixadhered Pb-Bi
Pb-Bi penetration
40 µm100 µm
W
Mo
Nb
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Weight Change of Refractory Metals
-50-25
0255075
100125150175200225250
W Mo Nb
Specimens
Wei
ght l
oss (
g/m
2)
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Conclusions
1. Al-Fe-coated steel, W, Mo, SiC and Ti3SiC2exibited good corrosion-resistance in LBE at 700 ºC.
2. Nb exibited poor corrosion-resistance in LBE at 700 ºC.
3. SiC/SiC composite showed that LBE penetrated into the matrix due to high porosity of the material, and a thin crack layer appearedin LBE at 700 ºC.