| |
High Corrosion Resistant Steels in
Waste - to - Energy Boilers
|
Comparison of Sumitomo high corrosion
resistant steels
|
Test
conditions
|
Specimen
Size
|
15mmwx15mmLx3mmw |
Gas
Atmosphere
|
1500ppmHCl-100ppmSO2-7.5%O2-7.5%CO2-20%H2O-bal.N2 |
Corrosion
Temperature |
450°C, 500°C,
550°C |
Corrosion
Time |
20h |
Test
Method |
ash of 30 mg/cm2 coated |
| 9wt%Cl ash
(mixture of ash A and B <1:3>) |
Ash |
A. 30mol%PbCl2-30mol%FeCl2-20mol%NaCl-20mol%KCl |
| B. 37.5mol%Na2SO4-37.5mol%K2SO2-25mol%Fe2O3 |
|
|
Comparison between HR11N and Alloy825 |
Chemical composition |
|
(mass%) |
|
C
|
Si
|
Mn
|
P
|
S
|
Ni
|
Cr
|
Mo
|
Cu |
A1 |
Ti |
N |
HR11N
|
 0.03 |
0.60 |
2.00 |
0.030 |
0.010 |
38.00
-42.00
|
27.00
-30.00
|
0.50
-1.50
|
－ |
－ |
－ |
0.100
-0.200
|
Alloy825
(UNS NO8825)
|
0.05 |
0.5 |
1.00 |
0.030 |
0.03 |
38.00
-46.00 |
19.50
-23.50
|
2.5
-3.5
|
1.5
-3.0
|
0.02 |
0.6
-1.2
|
－ |
|
|
 In
order to enhance the corrosion resistance
at high temperature, HR11N has high Cr
compared with Alloy 825.
Mo,
N addition is effective for increasing
localized corrosion resistance.
|
Comparison between Super 625 and Alloy625 |
| |
Chemical composition |
(wt%) |
|
C
|
Si
|
Mn
|
P
|
S
|
Ni
|
Cr
|
Mo
|
Ti
|
Nb
|
Fe
|
A1
|
Super
625
|
0.03 |
0.50 |
0.50 |
0.015 |
0.003 |
 0.50 |
20.0
-23.0 |
8.0
-10.0
|
－ |
0.51
-1.00
|
15.0
-20.0
|
0.40 |
Alloy625
(UNS NO6625)
|
0.10 |
0.50 |
0.50 |
0.015 |
0.015 |
58.0 |
20.0
-23.0 |
8.0
-10.0 |
0.40 |
3.15
-4.15
|
5.0 |
0.40 |
|
|
In
order to improve thermal stability and
hot workability, Super625 has optimum Nb
content.
Fe
content of Super625 is higher than that of
Alloy625. However, Fe content between 3~20
wt % does not influence high temperature
corrosion resistance in the presence of chloride.
|
