Description
Key Advantages
Unmatched Corrosion Resistance
Resists pitting, crevice corrosion, and sulfide stress cracking in seawater, H₂S-rich oilfields, and acidic chlorides (pH 1–12).
Compliant with NACE MR0175 for sour service applications.
Mechanical Superiority
620 MPa minimum yield strength—ideal for high-pressure pipelines and subsea umbilicals.
Maintains ductility down to -50°C (EN 10216-5 certified).
Cost Efficiency
Thinner walls reduce material use by 30–40% vs. 316L, lowering lifetime costs.
Sustainable Design
100% recyclable with lower nickel content than austenitic grades, aligning with ISO 14044 LCA standards.
Global Standards & Grades
| Region |
Standard |
Grade |
Surface Finish |
| USA |
ASTM A789/A790 |
UNS S32205 |
Pickled, Bright Annealed |
| Europe |
EN 10216-5 |
1.4462 |
Sandblasted (Ra 3.2–6.3 µm) |
| Asia-Pacific |
JIS G3463 |
SUS 329J3L |
Electropolished (Ra ≤0.5 µm) |
Technical Specifications
Chemical Composition (wt%)
| Cr |
Ni |
Mo |
N |
C |
Mn |
Fe |
| 22–23% |
4.5–6.5% |
3.0–3.5% |
0.14–0.20% |
≤0.03% |
≤2.0% |
Balance |
Mechanical Properties
| Condition |
Yield Strength |
Tensile Strength |
Hardness (HV) |
Impact Toughness |
| Solution Annealed |
≥450 MPa |
620–880 MPa |
290–350 |
≥100 J (-50°C) |
Critical Applications
Oil & Gas
Subsea pipelines, pressure vessels, and heat exchangers in sour gas environments.
Chemical Processing
Reactor tubes, nitric acid condensers, and urea stripper columns.
Marine Engineering
Seawater intake systems, offshore platform structural supports.
Renewable Energy
Geothermal brine piping, hydrogen production electrolyzers.
Fabrication Guidelines
Welding
Use duplex-specific filler metals (e.g., ER2209) with argon shielding gas.
Maintain interpass temperature below 150°C to avoid sigma phase formation.
Heat Treatment
Solution anneal at 1020–1120°C followed by rapid water quenching.
Cutting & Machining
Optimize tool speeds to 60–80% of 316L rates; use carbide tools for precision.
Quality Assurance
Testing Protocols:
100% PMI (Positive Material Identification) via XRF.
Hydrostatic testing at 1.5× design pressure (ASME B31.3 compliant).
Certifications:
NORSOK M-650 (offshore), PED 2014/68/EU (pressure equipment), ASME Section VIII.
FAQs
Q1: How does Duplex 2205 compare to Super Duplex 2507?
A1: 2205 offers a balance of cost and performance (PREN 34 vs. 2507’s PREN 42), ideal for moderately aggressive environments. 2507 suits hyper-chlorinated applications.
Q2: Can it replace titanium in seawater systems?
A2: Yes—for temperatures ≤80°C and chlorides ≤50.000 ppm, 2205 provides cost-effective corrosion resistance.
Q3: Is post-weld heat treatment required?
A3: Generally unnecessary if proper welding procedures (e.g., controlled heat input) are followed.
Q4: Maximum operating temperature?
A4: 300°C (572°F) continuous; short-term peaks up to 450°C (842°F) in non-oxidizing conditions.
Q5: How to prevent galvanic corrosion when paired with carbon steel?
A5: Use dielectric insulation or apply protective coatings (e.g., epoxy) on carbon steel surfaces.
