Super duplex 2507 · UNS S32750 · W. Nr. 1.4410 · 022Cr25Ni7Mo4N · ASTM A182 F53
Super Duplex Stainless Steel 2507 (S32750): composition, properties, fittings and flanges
Super duplex stainless steel 2507 (UNS S32750, W. Nr. 1.4410, ASTM A182 F53) contains 24-26 % chromium, 6-8 % nickel, 3-4 % molybdenum and 0.24-0.32 % nitrogen. Its pitting resistance equivalent number is typically above 40, and minimum properties are 800 MPa (116 ksi) tensile strength, 550 MPa (80 ksi) yield strength and 15 %…
- UNS
- S32750
- W. Nr.
- 1.4410
- Density
- 7.80 g/cm³ (0.281 lb/in³)
- Key strength
- 800 MPa / 116 ksi
Identification and standards
| Short form | Super duplex 2507 · UNS S32750 · W. Nr. 1.4410 · 022Cr25Ni7Mo4N · ASTM A182 F53 |
|---|---|
| Classification | 25 % chromium super duplex stainless steel |
| UNS | S32750 |
| Werkstoff number | 1.4410 |
| Material family | Stainless Steel |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Chromium (Cr) | 24.0 - 26.0 | Passive film, pitting resistance |
| Nickel (Ni) | 6.0 - 8.0 | Austenite phase balance |
| Molybdenum (Mo) | 3.0 - 4.0 | Pitting and crevice resistance |
| Nitrogen (N) | 0.24 - 0.32 | Strength and pitting resistance, austenite stabiliser |
| Copper (Cu) | 0.50 max | - |
| Manganese (Mn) | 1.20 max | - |
| Silicon (Si) | 0.80 max | - |
| Phosphorus (P) | 0.035 max | - |
| Sulphur (S) | 0.020 max | - |
| Carbon (C) | 0.030 max | - |
| Iron (Fe) | Balance | Matrix |
Note Single figures are maximum limits unless shown as a range. Always confirm against the heat-specific EN 10204 3.1 certificate supplied with your order.
Mechanical properties
| Tensile strength, min (ASTM A240) | 800 MPa / 116 ksi |
|---|---|
| 0.2 % yield strength, min | 550 MPa / 80 ksi |
| Elongation in 2 in, min | 15 % |
| Maximum hardness | 310 HB / 32 HRC |
| Typical pitting resistance equivalent number | Above 40 |
| Recommended service temperature range | -50 °C to 300 °C |
Warning Values depend on product form, section thickness and heat treatment. Larger sections generally achieve lower strength than thin product; always design against the applicable code allowable stress rather than these figures.
Physical properties
| Density | 7.80 g/cm³ (0.281 lb/in³) |
|---|---|
| Melting range | Approximately 1350 °C (2460 °F) |
| Modulus of elasticity | 200 GPa (29 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 14.0 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 12.0 µm/m·°C |
| Electrical resistivity at 20 °C | 0.80 µΩ·m |
| Magnetic behaviour | Magnetically responsive because of the ferritic phase |
Specifications by product form
| Pipe, seamless / welded | ASTM A790 / A928 / ASME SA-790 |
|---|---|
| Tube | ASTM A789 |
| Plate / sheet / strip | ASTM A240 / ASME SA-240 (UNS S32750) |
| Bar / rod / shapes | ASTM A276 / A479 / ASME SA-479 |
| Forgings & flanges | ASTM A182 Grade F53 / ASME SA-182 |
| Butt weld fittings | ASTM A815 / ASME SA-815 (WP25Cr7Ni4Mo3N) |
| Welding consumables | ER2594 filler to AWS A5.9 for matching pitting resistance |
| UNS / EN / China | UNS S32750 · W. Nr. 1.4410 · GB 022Cr25Ni7Mo4N |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Seamless and welded pipe to standard schedules
- Butt weld elbows, tees, reducers and caps to ASME B16.9
- Forged flanges to ASME B16.5 Class 150-2500
- Cast and machined pump components
Typical applications
- Subsea umbilicals, flowlines, manifolds and Christmas tree piping
- Seawater injection, produced water and high pressure reverse osmosis systems
- Offshore firewater ring mains and deluge systems
- Desalination high pressure membrane piping and energy recovery devices
- Chemical process vessels, heat exchangers and pickling lines
- Sour gas handling to NACE MR0175 / ISO 15156 limits
- Hydraulic and instrumentation tubing on offshore platforms
Welding, forming and machining
- Welding
- Weld with ER2594 over-alloyed filler to preserve pitting resistance in the weld metal. Heat input between roughly 0.5 and 1.5 kJ/mm and interpass temperature below 100 °C; root shielding with argon or high purity nitrogen is mandatory.
- Heat treatment
- Solution anneal at 1025-1125 °C followed by water quench. Because the alloy is prone to sigma precipitation, exposure between roughly 550 °C and 1000 °C should be minimised and the material must never be slow cooled.
- Forming
- Very high strength demands significantly higher forming forces than 316L or even 2205, with greater springback allowance.
- Machining
- More demanding than 2205. Use rigid setups, premium carbide grades, lower cutting speeds and flood coolant for acceptable tool life.
Buy Super Duplex Stainless Steel 2507 from Hangbo
Material is supplied with full heat-number traceability, solution annealing or ageing performed under calibrated furnace control, and an EN 10204 3.1 certificate covering chemical analysis, mechanical properties, heat treatment records and the agreed NDT scope. Positive material identification and third party inspection and test reports from SGS are available for critical service.