7. corrosion abo
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Performance of superheater materials
in simulated oxy-fuel combustion
conditions at 650C
Modified from
EUROCORR 20114-8 Sept, Stockholm
D. Bankiewicz1, S. Tuurna2, P. Yrjas1, P. Pohjanne2
1bo Akademi University, Turku, Finland2VTT Research Centre, Tampere/Espoo, Finland
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Test plan
Conditions Test length (h) CO2 O2 H2O N2 (vol%)
Oxy-fuel 1 168 60 4 0 36
Oxy-fuel 2 168 60 4 10 26
Oxy-fuel 3 168, 500, 1000 60 4 30 6
66.19
66.7
43.64
51.98
18.3
18.6
23.56
26.1
11.7
11.6
24.08
19.46
5.3 2.83
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
TP347HFG
TP347HFG_1
Sanicro 25
HR3C
Fe Cr Ni W Cu
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Laboratory method for HT corrosion tests
1. Preparation of salts
2. Preparation of steel samples for the experiment
3. Tube furnace tests
4. Preparation of samples for SEM/EDXA
5. Analysis of SEM results
1. Preparation of salts
2. Preparation of steel samples for the experiment
3. Tube furnace tests
4. Preparation of samples for SEM/EDXA
5. Analysis of SEM results
1. Preparation of salts
2. Preparation of steel samples for the experiment
3. Tube furnace tests
4. Preparation of samples for SEM/EDXA
5. Analysis of SEM results
1. Preparation of salts
2. Preparation of steel samples for the experiment
3. Tube furnace tests
4. Preparation of samples for SEM/EDXA
5. Analysis of SEM results
1. Preparation of salts
2. Preparation of steel samples for the experiment
3. Tube furnace tests
4. Preparation of samples for SEM/EDXA
5. Analysis of SEM results
0
50
100
150
200
250
0 500 1000 1500 2000 2500 3000 3500 4000Oxidelaye
rthickness[m]
Cross section [m]
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HR3C
Sanicro25
3
47HFG
0
20
40
60
80
100
168 h 500 h1000 h
Oxidelayer
thickness,m
Oxide layer thickness 347HFG after exposures in
60%CO2-30%H2O with CaCO3-CaSO4
- carburization of the material
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Carburization of 347HFG after exposure to
85CaCO3+ 15CaSO4, 650 C
60% CO2, 30% H2O
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No carburization of 347HFG after exposure to
CaSO4, 650 C
60% CO2, 30% H2O
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4. Tests in 60% CO2, 30% H2Owith pure CaSO4at 650 C
no measurable oxide layer was found on the samples no carburization
3. Tests in 60% CO2, 30% H2Owith 85 CaCO3+ 15 CaSO4at 650 C
measurable oxide layer just on 347HFG material clear carburization of 347HFG after 168, 500 and 1000 h exposures
Conclusions and wrap up of tests in high CO2
2. Tests in 60% CO2, 30% H2Owith no salt at 650 C
no measurable oxide layer was found on the samples no carburization oxide layer growth on 347HFG after longer exposures (500, 1000h)
1. Tests in 60% CO2, no H2O with no salt at 650 C
no measurable oxide layer was found on the samples
no carburization
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Is the lower resistance of 347HFG in high CO2atmosphere caused by water
vapor? Differences in 347HFG vs. 347HFG_1 performance?
347HFGvs. 347HFG_1
Molybdenum was reported to have a negative effect in water vapour. Mo can formhighly volatile hydroxyl what can increase the tendency of scale cracking and havean impeding effect on scale healing [1].
Here 347HFG 0.23Movs. 347HFG_1 0.04Mo
HR3C and Sanicro 25 no Mo and Cr content is > 20%
Generally lower resistance of 347HFG too low Cr content
[1] Schtze et al. Materials Research, Vol. 7. 1, 111-123, 2004
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