Advanced duplex stainless steel with dual-phase microstructure providing exceptional strength and superior corrosion resistance for demanding applications.
50% austenite + 50% ferrite for optimal properties
2x stronger than 316L austenitic grades
PREN 33+ for excellent pitting resistance
Outstanding resistance in chloride environments
Best of both phases combined
| Property | Austenite Phase | Ferrite Phase | Combined Benefit |
|---|---|---|---|
| Strength | Good ductility and toughness | High strength and hardness | Excellent strength-toughness balance |
| Corrosion Resistance | General corrosion resistance | Pitting and crevice resistance | Superior overall corrosion performance |
| Stress Corrosion Cracking | Good resistance | Excellent resistance | Outstanding SCC resistance |
| Fabrication | Good formability | High strength | Good workability with high strength |
UNS S31803 - F51 Duplex
| Element | Min | Max |
|---|---|---|
| Carbon(C) | - | 0.03 |
| Silicon(Si) | - | 1.00 |
| Manganese(Mn) | - | 2.00 |
| Phosphorus(P) | - | 0.030 |
| Sulfur(S) | - | 0.020 |
| Chromium(Cr) | 21.00 | 23.00 |
| Nickel(Ni) | 4.50 | 6.50 |
| Molybdenum(Mo) | 2.50 | 3.50 |
| Nitrogen(N) | 0.08 | 0.20 |
| Iron(Fe) | Balance | Balance |
Pitting Resistance Equivalent Number
| Grade | PREN | Resistance |
|---|---|---|
| S31803 F51 | 33+ | Good |
| 316L | 25 | Fair |
| S32205 F60 | 35 | Better |
| S32760 F55 | 42+ | Excellent |
Solution Annealed & Water Quenched
| Condition | UTS | Yield | Elongation | CVN Impact | Hardness |
|---|---|---|---|---|---|
| Solution Annealed | 90 KSI Min | 65 KSI Min | 25% | 40 J @ -40°C | ≤32 HRC |
| Test Type | F51 Performance | Comparison |
|---|---|---|
| Pitting Resistance (PREN) | 33+ | 2x better than 316L |
| Crevice Corrosion | Excellent | Superior to austenitic grades |
| Stress Corrosion Cracking | Outstanding | Highly resistant in chlorides |
| General Corrosion | Very Good | Similar to high-grade austenitics |
| Erosion Corrosion | Excellent | Better than single-phase alloys |
| Galvanic Compatibility | Good | Compatible with 316L systems |
| Environment | Resistance | Notes |
|---|---|---|
| Seawater | Excellent | Outstanding performance in marine environments |
| Chloride Solutions | Excellent | High PREN provides superior pitting resistance |
| Organic Acids | Very Good | Better than 316L in many acids |
| Caustic Solutions | Good | Suitable for moderate caustic environments |
| H2S Environments | Excellent | Superior stress corrosion cracking resistance |
| High Temperature | Good | Service up to 300°C (572°F) |
Enhanced duplex with higher nitrogen content
Super duplex with tungsten addition
Standard austenitic stainless steel
Leverage the superior strength and corrosion resistance of duplex technology for your most demanding marine, chemical, and offshore applications.