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 2205 Stainless Steel (UNS S31803 / S32205)
Duplex 2205 is the most-specified standard duplex stainless steel grade globally, used in chemical processing, oil & gas, marine moderate-chloride service, pulp & paper, and food & beverage industries. Designated UNS S31803 / S32205 in the North American Unified Numbering System and EN 1.4462 / X2CrNiMoN22-5-3 under European Standards. Nominal composition: 22 Cr – 5 Ni – 3 Mo – 0.15 N; PREN ~35 (below the super duplex PREN ≥ 40 threshold). Above standard-duplex limits, super-duplex grades like Ferralium 255 are specified.
Duplex 2205 Overview
Duplex 2205 has a balanced two-phase austenite-ferrite microstructure (35–55% ferrite per NORSOK M-630), supplied solution-annealed at ~1050 °C with water quench. The grade combines the high strength of ferritic stainless steel (yield ≥ 450 MPa, tensile ≥ 620 MPa) with the corrosion resistance of austenitic stainless steel. It is approximately twice as strong as 304/316L austenitic stainless steel at room temperature, allowing thinner-section component design.
Mechanical Properties
| Property | Minimum (Duplex 2205) | Test standard |
|---|---|---|
| 0.2% Yield strength (Rp0.2) | 450 MPa (65 ksi) | ASTM E8 |
| Ultimate tensile strength (Rm) | 620 MPa (90 ksi) | ASTM E8 |
| Elongation (A5) | 25% | ASTM E8 |
| Hardness, max | 293 HBW (~32 HRC NACE limit) | ASTM E18 |
| Charpy V-notch at −46 °C, min | 45 J (NORSOK M-630) | ASTM E23 |
| Density | 7.80 g/cm³ | none |
Chemical Composition
Full element-by-element composition table on Duplex 2205 chemical composition page. Summary: Cr 22–23%, Ni 4.5–6.5%, Mo 3.0–3.5%, N 0.14–0.20%, no Cu (vs Ferralium 255 with 1.5–2.5% Cu). PREN = %Cr + 3.3·%Mo + 16·%N ≈ 35 typical per heat.
Typical Applications
- Chemical processing, organic acids, phosphate fertilizer, dyes, pharmaceutical intermediates
- Pulp & paper digesters and bleach plant equipment
- Oil & gas low-CO2 environments (above CO2 partial-pressure thresholds, super duplex required)
- Moderate-chloride seawater (typical ≤ 30 °C; warmer seawater requires super duplex)
- Food & beverage processing equipment
- Storage tanks for moderate-chloride brines
When to Upgrade to Super Duplex
Duplex 2205 service limits become binding when: chloride concentration exceeds typical seawater (3.5% NaCl); service temperature exceeds 30 °C in chloride environments; sour-gas (H2S) partial pressure exceeds NACE MR0175 thresholds for standard duplex; or when reducing acids (HCl, dilute H2SO4) are present. In these conditions, upgrade to a super duplex grade with PREN ≥ 40 such as Ferralium 255 (UNS S32550). See Ferralium 255 vs Duplex 2205 upgrade decision guide.
Spec Compliance
- ASTM A479 (bar), A240 (plate/sheet), A789 (tube), A790 (pipe), A815 (fittings), A182 (forgings)
- EN 10088-3 (1.4462), EN 10222-5 (forgings)
- NORSOK M-630 material data sheet (MDS D45)
- NACE MR0175 / ISO 15156-3 sour-service compliance per heat
Need Duplex 2205 (UNS S31803 / S32205) bar, plate, pipe, fittings, flanges, fasteners? 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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