Surface Treatments
Certifications
- ISO 9001:2015
- NORSOK M-650
- NACE MR0175
- ISO 15156-3
- PED 2014/68/EC
- EN 10204 type 3.2
- AD 2000 W2/W7/W10
Duplex Stainless Steel: UNS S31803 / S32205 (Duplex 2205) Reference
Duplex stainless steel is the family of two-phase (austenite + ferrite) stainless steels with balanced microstructure, typically 35–55% ferrite per NORSOK M-630. The most-specified standard duplex grade is Duplex 2205 (UNS S31803 / S32205). Super-duplex grades like Ferralium 255 (UNS S32550) extend the corrosion-resistance envelope above Duplex 2205 limits via higher Cr / Mo / N and Cu addition.
Duplex 2205 (UNS S31803 / S32205): The Standard Duplex Grade
Composition: Cr 22%, Ni 5%, Mo 3%, N 0.15%. PREN ~35. EN designation 1.4462 / X2CrNiMoN22-5-3. Original UNS S31803 specification (1980s) permitted wider Cr / Mo / N ranges; modern UNS S32205 (1996+) narrowed these to guarantee PREN ≥ 35 per heat. Most current mill heats are dual-certified S31803 / S32205 by hitting the narrower S32205 ranges.
Duplex 2205 Chemical Composition
| Element | UNS S31803 | UNS S32205 |
|---|---|---|
| Carbon (C), max. | 0.030 | 0.030 |
| Chromium (Cr) | 21.0–23.0 | 22.0–23.0 |
| Nickel (Ni) | 4.5–6.5 | 4.5–6.5 |
| Molybdenum (Mo) | 2.5–3.5 | 3.0–3.5 |
| Nitrogen (N) | 0.08–0.20 | 0.14–0.20 |
| Manganese (Mn), max. | 2.00 | 2.00 |
| Sulphur (S), max. | 0.020 | 0.020 |
| Phosphorus (P), max. | 0.030 | 0.030 |
Full chemistry detail on Duplex 2205 chemical composition page.
Duplex 2205 Mechanical Properties
| Property | Minimum (Duplex 2205) |
|---|---|
| Yield strength (Rp0.2) | 450 MPa (65 ksi) |
| Tensile strength (Rm) | 620 MPa (90 ksi) |
| Elongation (A5) | 25% |
| Hardness, max | 32 HRC (NACE MR0175) |
| Density | 7.80 g/cm³ |
| Charpy at –46 °C, min (NORSOK) | 45 J |
Duplex 2205 vs Super Duplex Grades
Above Duplex 2205 service limits (warm seawater, high chlorides, aggressive sour gas, reducing acids), super-duplex grades like Ferralium 255, Super Duplex 2507, or Zeron 100 are required. See Ferralium 255 vs Duplex 2205 upgrade guide and Duplex 2205 vs Super Duplex 2507 comparison for selection criteria.
ASTM Specifications for Duplex 2205
Bar: ASTM A479 (UNS S31803, S32205). Plate / sheet: ASTM A240. Pipe: ASTM A790. Tube: ASTM A789. Fittings: ASTM A815. Forgings: ASTM A182 (grade F51 for S31803, F60 for S32205). EN equivalents: EN 10088-3 (1.4462), EN 10222-5 (forgings), EN 10272 (pressure-rated bar). NORSOK M-630 material data sheet MDS D45.
Need Duplex stainless steel (2205)? Email info@torqbolt.com or WhatsApp +91-22-66157017 with form, dimensions, quantity, ASTM/EN spec, MTC level (3.1 / 3.2). NACE MR0175 sour-service stamp on every heat. NORSOK M-650 QTR on request. Per-heat EN 10204 type 3.2 MTC included with every consignment.
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