 |
S32205 Duplex Stainless Steel Tube/Plate (UNS S32205)
S32205 duplex stainless steel (UNS S32205) is a second-generation duplex alloy engineered to deliver superior strength and chloride resistance. With a balanced austenitic-ferritic microstructure, this s32205 material exceeds conventional stainless steels in:
Yield strength (2× higher than 316L).
Stress corrosion cracking (SCC) resistance.
Pitting/crevice corrosion resistance (PREN ≥ 35).
UNS S32205 and ASTM A182 F60 is a duplex grade with a ferritic-austenitic microstructure consists of around 40-50% ferrite in the annealed condition.
Sheets/Plates and strips: ASTM A240 and ASME SA240;
Bars/Rounds: ASTM A276 and ASME SA276;
Seamless and welded pipes/tubes: ASTM A789 and ASME SA789; ASTM A790 and ASME SA790; ASTM A312 and ASME SA312.
Duplex S32205 has the high strength of the ferritic grades whilst retaining the corrosion resistance of the austenitic grades.
UNS S32205 has superior resistance to chloride pitting and crevice corrosion as compared to 317L stainless steel, Alloy 2205(UNS S32205) has outstanding corrosion resistance to seawater and most concentrations of sulphuric acid.
In addition, 2205 duplex stainless is also resistant to sulphide stress corrosion cracking (sour-gas environments). These high quality corrosion resistance, resistance to stress corrosion cracking and therefore performance are widely attributed to its high levels of chromium present as well as nitrogen and molybdenum.
Grade | C≤ | Mn≤ | P≤ | S≤ | Si≤ | Ni | Cr | Mo | N |
S32205 | 0.04 | 2 | 0.03 | 0.02 | 1.00 | 4.5–6.5 | 22.0–23.0 | 3.0–3.5 | 0.14–0.20 |
Grade | Tensile, min, ksi[MPa] | Yield, min, ksi[MPa] | Elongation, %(min) | Hardness, HB（max） |
S32205 | 95 [655] | 65 [450] | 25 | 293 |
Code | 2205 | |
Density (kg/m3) | 7800 | |
Elastic Modulus (GPa) | 190 | |
Thermal Expansion (μm/m/°C) | 0-100°C | 13.7 |
0-315°C | 14.2 | |
0-538°C | - | |
Thermal Conductivity (W/m.K) | at 100°C | 19 |
at 500°C | - | |
Specific Heat ( J/kg.K) | 0-100°C | 418 |
Electrical Resistivity (nΩ.m) | 850 | |
This is a comparison table of grades for S32205 Duplex Steel, comparing functionally similar materials.
STANDARD | WERKSTOFF NR. | UNS | EN |
Duplex S32205 | 1.4462 | S32205 | X2CrNiMoN22-5-3 |
Product Name | Standard | Show |
Pipe SMLS& Welded | ASTM A790 |  |
Tube SMLS& Welded | ASTM A789 |  |
Sheet/Plate | ASTM A240 |  |
Bar /Rod | ASTM A276/A479 |  |
Forging /Flange | ASTM A182 F60 |  |
BW Fittings | ASTM A815 |  |
Here's a precise technical comparison of S31803 vs S32205 duplex stainless steels, based on international standards (ASTM/ISO) and industrial data:
Parameter | UNS S31803 (1st Gen Duplex) | UNS S32205 (2nd Gen Duplex) |
PREN① | 31-32 | ≥35 |
Nitrogen (N) Content | 0.08-0.20% | 0.14-0.20% (Tighter control) |
Critical Pitting Temp. | ≤25°C (ASTM G48) | ≥35°C (ASTM G48) |
Yield Strength | ≥450 MPa | ≥450 MPa |
Chloride Resistance | Moderate | Superior |
H₂S Service Limit | ≤0.1 psi H₂S (pH≥4.5) | ≤3 psi H₂S (pH≥3.5) |
Modern Applications | Legacy systems | Current industry standard |
Why S32205 Replaced S31803？
Higher Corrosion Resistance
Higher nitrogen content in S32205 increases PREN by 12%, extending service life in: Seawater and HCl/Cl⁻ environments.
Improved Weldability
S32205's controlled N range (0.14-0.20%) prevents:
Excessive ferrite in HAZ (Heat-Affected Zones)
Secondary phase precipitation
Maintains 30-55% ferrite in welds (vs 20-70% in S31803).
Standardization Shift
Major standards ASTM A790/A240 now specify S32205 as baseline: s31803 remains acceptable only if properties meet S32205 minima.
New projects specify S32205 for critical service.
S31803 and S32205 duplex steel are mainly used in:
Chemical industry, paper industry, oil refining industry;
Seawater desalination equipment, seawater system;
Chemical tanker cargo hold and piping system;
Fire and explosion-proof walls of offshore platforms;
Bridges, structural design components;
Pressure vessels, heat exchangers;
Turbine blades and drive shafts;
Papermaking machinery, pulp equipment, etc.
