ASTM A182 F55 Super Duplex Stainless Steel Flange
ASTM A182 F55 Specification:
- Grade: A182 F51 Duplex Stainless Steel Flange
- Standard: ASTM A182
- Type: Duplex Stainless Steel Flange
- Form: Flanges (Slip-on Flange, Weld Neck Flange, Blind Flange, Socket Weld Flange, Threaded Flange, Lap Joint Flange, Plate Flange)
- Size: Available in various dimensions (½”, ¾”, 1”, 1 ¼”, 1 ½”, 2”, 2 ½”, 3”, 4”, 5”, 6”, 8”, 10”, 12”, 14”, 16”, 18”, 20”, 24”, 26”, 28”, 30”, 32”, 34”, 36”, 38”, 40”, 42”, 44”, 46”, 48”)
- Pressure Class: 150, 300, 600, 900, 1500, 2500
- End Types: Flanged, Threaded, Welded
ASTM A182 F55 Equivalent Materials:
- UNS: S31803
- AISI/SAE: Not specifically listed (closest match: Duplex 2205)
- JIS (Japan): SUS 329J3L
- DIN (Germany): X2CrNiMoN22-5-3
- EN (Europe): 1.4462 (X2CrNiMoN22-5-3)
- BS (British Standard): 318S13
- AFNOR (France): Z2CND22-05Az
- UNI (Italy): X2CrNiMoN22-5-3
- SS (Sweden): 2377
- GB (China): 00Cr22Ni5Mo3N
ASTM A182 F55 Chemical Composition:
| Element | Composition (%) |
|---|---|
| Chromium (Cr) | 21.0 - 23.0 |
| Nickel (Ni) | 4.5 - 6.5 |
| Molybdenum (Mo) | 2.5 - 3.5 |
| Manganese (Mn) | 2.0 max |
| Silicon (Si) | 1.0 max |
| Carbon (C) | 0.03 max |
| Phosphorus (P) | 0.03 max |
| Sulfur (S) | 0.02 max |
| Nitrogen (N) | 0.08 - 0.2 |
| Iron (Fe) | Balance |
ASTM A182 F55 Mechanical Properties:
| Property | Value |
|---|---|
| Yield Strength | 450 MPa (min) |
| Tensile Strength | 620 MPa (min) |
| Elongation at Break | 25% (min) |
| Hardness | 285 HB (max) |
ASTM A182 F55 Physical Properties:
| Property | Value |
|---|---|
| Density | 7.8 g/cm³ |
| Melting Point | 1399-1425°C |
| Thermal Conductivity | 14.8 W/m·K |
| Coefficient of Thermal Expansion (20°C to 100°C) | 15.3 µm/m°C |
Possible Alternative Grades:
| Alternative Grade | Characteristics |
|---|---|
| ASTM A182 F60 | Higher strength, good corrosion resistance |
| ASTM A182 F55 | Higher corrosion resistance in marine environments |
| ASTM A312 TP316L | Excellent resistance to pitting and crevice corrosion |
| ASTM A276 316L | General-purpose grade for corrosion-resistant applications |
Chemical Formula:
FeCrNiMoCuN (with varying percentages of the elements as listed above)
Grade Specification Comparison:
| Grade | Chromium (%) | Nickel (%) | Molybdenum (%) | Nitrogen (%) | Strength (MPa) |
|---|---|---|---|---|---|
| ASTM A182 F55 | 21.0 - 23.0 | 4.5 - 6.5 | 2.5 - 3.5 | 0.08 - 0.2 | 620 |
| ASTM A182 F55 | 20.0 - 22.0 | 6.0 - 8.0 | 2.5 - 3.0 | 0.10 - 0.2 | 700 |
| ASTM A182 F60 | 23.0 - 25.0 | 4.5 - 6.5 | 2.5 - 3.5 | 0.08 - 0.15 | 750 |
Corrosion Resistance:
ASTM A182 F55 Super Duplex Stainless Steel has excellent resistance to pitting, crevice corrosion, and stress corrosion cracking, particularly in chloride-containing environments. Its balanced microstructure provides superior resistance to corrosion compared to austenitic steels, especially in harsh chemical and marine environments.
Heat Resistance:
F51 exhibits good resistance to oxidation and scaling at elevated temperatures. However, it is not recommended for continuous service above 300°C (572°F) due to the risk of embrittlement. Short-term exposure to temperatures up to 600°C (1112°F) can be tolerated without significant degradation.
Heat Treatment:
The heat treatment process for ASTM A182 F55 Super Duplex Stainless Steel includes:
- Solution Annealing: Heated to 1020-1100°C (1870-2012°F) and rapidly cooled in water or air.
- Precipitation Hardening: Not applicable for this alloy.
- Stress Relieving: Performed at 300-400°C (572-752°F) if necessary.
Welding:
Welding of ASTM A182 F55 is recommended to be performed with a filler metal similar to the base material to maintain corrosion resistance. Proper heat control during welding is crucial to avoid sensitization (formation of chromium carbides), which could compromise the corrosion resistance. Common welding processes include TIG, MIG, and Stick welding.
Fabrication:
Fabrication of ASTM A182 F55 Super Duplex Stainless Steel can be done using conventional techniques such as cutting, grinding, machining, and forming. However, due to its high strength, the material may require more energy for machining compared to austenitic grades. Special care should be taken to avoid overheating during forming and welding.
Applications:
ASTM A182 F55 Super Duplex Stainless Steel Flanges are commonly used in:
- Oil and Gas Industry: Pipelines, pressure vessels, and offshore structures.
- Chemical Processing: Reactors, heat exchangers, and columns.
- Marine: Shipbuilding, seawater systems, and marine structures.
- Power Generation: Cooling towers, steam generators, and piping systems.