The Comments of Super304H Stainless Steel Boiler Tube
Austenitic steel Super 304H used for ultra-Supercritical boiler has been developed for ultra-Supercritical boiler tube application, it¡¯s inoxidibility at 650¡æ is better than common 18/28 stainless steel such as SA213 TP304H,SA213 TP347H and at the samec condition. it¡¯ s depth of oxide etch is half of SA213 TP304H,67 % of SA213 TP347H. The test approved that it¡¯s mechanical property of welding accord with Safety Technique Monitor of Steam Boiler and ASME requirement. In this paper, the properties and features of Super304H are comments detainledly. After comprehensive analyzing, it is regarded that Super304H is a kind of very suitable material to use for superheaters and reheaters of ultra-supercritical boilers.
Supplying Conditions and metallurgical structure:
We supply Super 304H in Full Solution Annealing (Solution Annealing Temperature no less than 1100¡æ) , The metallurgical structure is single Austenite structure.
Chemical Composition:
Super 304H Included Appropriate Nb and Cu to improve the steel strength,ductility and anti-corrosion capability.
|
Form |
C% |
Si% |
Mn% |
S% |
P% |
Cr% |
Ni% |
Cu% |
Nb% |
|
ASME Code 2328 |
0. 07- 0. 13 |
¡Ü 0.30 |
¡Ü 1. 00 |
¡Ü 0. 030 |
¡Ü 0. 045 |
17. 0-19. 0 |
7. 5-10. 5 |
2. 5-3. 5 |
0. 2-0.6 |
|
Steel Value |
0. 09 |
0. 23 |
0. 81 |
0. 001 |
0. 021 |
18. 75 |
9. 60 |
3. 05 |
0. 52 |
Physical Property:
The physical property of Super TP304H show as following form¢ò in normal temperature, also compared with SA213 TP304H and SA213 TP347H, The value of Super TP304H is much better than 18-8 stainless steel and ducility is almost the same as SA213 TP347H
|
Form¢ò |
Universal Physical Property |
Hardness |
Akv (0¡æ)/J |
|
Rm(MPa) |
Rp0. 2(MPa) |
A (%) |
HRB |
|
ASME Code 2328 |
¡Ý 550 |
¡Ý 205 |
¡Ý 35 |
¡Ü 90 (192HB) |
/ |
|
Super 304H
60.3 ODX13 WTH |
608/605 |
318/315 |
45/48 |
82/83 |
235/239 |
|
SA213 TP304H |
¡Ý 515 |
¡Ý 205 |
¡Ý 35 |
/ |
/ |
|
SA213 TP347H |
¡Ý 515 |
¡Ý 205 |
¡Ý 35 |
¡Ü 90 (192HB) |
/ |
Endurance Strength in High Temperature
Under 650¡æ with 105 Hours Test Environment, Super 304H show excellent endurance strength capability, the test value is 122 MPa, much better than 79 MPa for SA213 TP347H.
Long-term Aging Performance
Against 650¡æ with 5000 Hours Test Environment,It prove that Super 304H has no changes in physical properties, such as strength, ducility and hardness, the attact impact property has slight changes following the times, but the value is still in high level.
Vapor Oxidation Resistance
Due to the fine grain size of Super TP304H and include 0.52%Nb, It's Anti-corrosion capability is usually better than SA213 TP304H, but less than SA213 TP347H. Against the anti-corrosion test under 650¡æ, we find that the anti-corrosion capability under high temperature in Super TP304H is better than SA213 TP304H and SA213 TP347H, it's depth of oxide etch is half of SA213 TP304H,67 % of SA213 TP347H.
We recommend you Super TP304H for your boiler tubes for high termperaturer service, for more technique information, please contact us.
By Eris in Press Center of Lord Steel Industry Company Limited
News@lordsteel.com |
