Duplex Stainless Steel S31803 / S32205
Duplex stainless steel S31803/S32205 is a nitrogen-enhanced alloy with a mixed austenitic-ferritic microstructure. This duplex structure provides significantly higher strength than conventional austenitic stainless steels while maintaining good toughness and corrosion resistance.
The alloy exhibits excellent resistance to stress corrosion cracking, pitting, and crevice corrosion in chloride-containing environments. It is widely used in oil & gas, chemical processing, pressure vessels, and marine applications.
Specifications
- UNS: S31803/S32205
- ASTM: A182 F51/F60, A276
- EN / DIN: 1.4462
- Structure: Duplex (Austenitic + Ferritic)
- Condition Supplied: Solution Annealed
Data Tables
Chemical Composition:
| C | Mn | P | S | Si | Cr | Ni | Ti | Mo | N | Cu | Fe | Co | Nb (+Ta) | V | W | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 21 | 4.5 | 2.5 | 0.08 | |||||||||||||
| Max | 0.03 | 2 | 0.03 | 0.2 | 1 | 23 | 6.5 | 3.5 | 0.2 | Bal |
Mechanical Properties:
| Material Grade | ASTM Standard | Desgnation(EN /UNS) | Yield Strength (MPa) | Yield Strength (KSI) | Tensile Strength (MPa) | Tensile Strength (KSI) | Elongation (%) | Reduction of Area (%) | Hardness(HRC/HBWMax) | Condition | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Duplex (F51/F60) | ASTM A276 / A182 / A479 | EN 1.4462(S31803 / S32205) | 450 | 65.2671 | 655 | 94.99989 | 25 | 45 | 290 BHN | Solution Annealed |
Physical Properties:
| Material Grade | Density (g/cm³) | Melting Range (°C) | Modulus of Elasticity (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion (×10⁻⁶ /°C) | Electrical Resistivity (µΩ·m) | Magnetic Behavior |
|---|---|---|---|---|---|---|---|
| Duplex S31803 / S32205 | 7.8 | 1350–1400 | 200 | 19 | 13 | 0.85 | Partially magnetic |
Key Features
- Duplex microstructure provides high strength
- Excellent resistance to stress corrosion cracking
- Good resistance to pitting and crevice corrosion
- Better fatigue resistance than austenitic stainless steels
- Cost-effective alternative to high-nickel alloys
Applications
- Oil and gas processing equipment
- Pressure vessels and storage tanks
- Heat exchangers
- Marine and offshore structures
- Chemical processing plants