Deutsche Version: Duplex-Formstücke 1.4462
X2CrNiMoN22-5-3 · S31803 / S32205 · Duplex 2205 · EN 10253-4 Type B
Standard duplex stainless steel. PRE ≥35. 2× the yield strength of 316L. NACE MR0175 compliant for sour gas service. The dominant grade for offshore, subsea, and chloride-aggressive process piping where 316L falls short.
Duplex stainless steels have a two-phase austenite-ferrite microstructure (approximately 50/50 by volume). This delivers three simultaneous advantages over purely austenitic grades like 316L: higher yield strength (≥450 MPa vs ~220 MPa for 316L), higher pitting resistance (PRE ≥35 vs ~24 for 316L), and much better resistance to chloride stress corrosion cracking (SCC). The SCC immunity comes from the ferritic phase interrupting propagation pathways.
The higher strength means wall thickness can be reduced relative to 316L for the same pressure rating — partially offsetting the material cost premium. In offshore piping, the combined corrosion + strength performance of duplex 2205 makes it the default over either CS (corrosion) or 316L (insufficient strength and chloride resistance) for topside and subsea chloride environments.
| Element | Min | Max | Role |
|---|---|---|---|
| Carbon (C) | — | 0.030% | Low C — weldability |
| Chromium (Cr) | 21.0% | 23.0% | Passivation, PRE contribution |
| Nickel (Ni) | 4.5% | 6.5% | Austenite stabiliser |
| Molybdenum (Mo) | 2.5% | 3.5% | Pitting resistance (PRE) |
| Nitrogen (N) | 0.10% | 0.22% | Austenite stabiliser + PRE |
PRE = %Cr + 3.3×%Mo + 16×%N. Typical PRE ≥35 for 1.4462.
| Property | 316L (1.4404) | Duplex 2205 (1.4462) | Super Duplex (1.4410) |
|---|---|---|---|
| PRE | ~24 | ≥35 | ≥40 |
| Yield strength | ~220 MPa | ≥450 MPa | ≥530 MPa |
| Chloride SCC resistance | Poor | Good | Excellent |
| NACE MR0175 | Conditional | Yes (hardness cert) | Yes (hardness cert) |
| Max service temp | ~300°C | ~300°C | ~300°C |
| Sigma phase risk | Low | Above 300°C | Above 280°C |
| Filler | ER316L | ER2209 | ER2594 |
Above approximately 300°C, sigma phase (σ) can precipitate in duplex stainless steels, causing severe embrittlement. This restricts duplex 2205 to process temperatures below 300°C. For piping systems that cycle through higher temperatures (e.g. steam purge, CIP/SIP in pharmaceutical), confirm that the peak temperature never exceeds this limit. At ambient chloride service temperatures, duplex is unrestricted.
| EN number | 1.4462 |
| EN designation | X2CrNiMoN22-5-3 |
| UNS | S31803 / S32205 |
| PRE (min) | ≥35 |
| Yield strength | ≥450 MPa |
| NACE MR0175 | Compliant |
| Max service temp | ≤300°C |
| Filler (GTAW) | ER2209 |
| PWHT | Not required |
| Standard | EN 10253-4 Type B |
| Certificate | EN 10204 3.1 standard |
NACE MR0175 hardness certificate. EN 10204 3.1 standard. 3.2 (Lloyd's / BV / DNV) available for offshore. PMI on every duplex order.
Get QuoteDN15–DN600 and larger. Outside diameters follow the EN 10220 / EN ISO 1127 pipe series; wall thickness is matched to your connecting pipe.
| Size | OD (mm) |
|---|---|
| DN 15 | 21.3 |
| DN 20 | 26.9 |
| DN 25 | 33.7 |
| DN 32 | 42.4 |
| DN 40 | 48.3 |
| DN 50 | 60.3 |
| DN 65 | 76.1 |
| DN 80 | 88.9 |
| DN 100 | 114.3 |
| DN 125 | 139.7 |
| DN 150 | 168.3 |
| DN 200 | 219.1 |
| DN 250 | 273.0 |
| DN 300 | 323.9 |
| DN 350 | 355.6 |
| DN 400 | 406.4 |
| DN 450 | 457.0 |
| DN 500 | 508.0 |
| DN 600 | 610.0 |
Yes, 1.4462 fittings are supplied compliant with NACE MR0175 for sour gas service.
Its minimum yield strength (450 MPa) is about twice that of 316L, and its PRE is at least 35, so it is used offshore and in chloride-aggressive process piping where 316L falls short.
Service up to about 300°C; ER2209 filler for GTAW; PWHT is not required.
Supplying an Indian boiler or ASME B16.9 project? The equivalent grade is listed on our group site ibrfittings.com: Duplex 2205 fittings.
