Super Duplex SS Steel Sheet
Super duplex 2507 and Zeron 100 sheet and plate from 2 mm to 60 mm to ASTM A240 / ASME SA240 — PREN above 40, 550 MPa yield, cut and bevelled to plan with G48 and A923 test reports.
What is Super Duplex Steel Sheet & Plate?
Super duplex sheet and plate is high-alloy dual-phase flat product with a PREN above 40, specified where warm seawater, brine or sour fluids would pit standard duplex. Steelco stocks UNS S32750 (2507), S32760 (Zeron 100) and S32550 from 2 mm to 60 mm to ASTM A240 / ASME SA240 in 2B and No.1 finishes, with 550 MPa minimum yield, 795 MPa minimum tensile and ASTM G48 Method A testing at 50 °C on every heat.
All grades we stock in super duplex steel sheet & plate.
Click any grade for its full chemical composition, mechanical properties, equivalents and typical applications. Every grade ships with EN 10204 3.1 / 3.2 certification from our Mumbai stockyard.
Why Choose Super Duplex Steel Sheet & Plate
Seawater-grade corrosion resistance
PREN 41–43 keeps the alloy passive in warm chloride environments that pit both 316L and 2205.
550 MPa minimum yield
Design strength allows thinner shells and lighter offshore modules, reducing structural and lifting costs.
NORSOK M-601 fabrication
Supplied with the documentation package North Sea projects require, including ferrite count and G48 results.
Sour-service capable
NACE MR0175 / ISO 15156 compliant in the solution-annealed condition with hardness capped at 32 HRC.
Cut and bevelled to plan
Waterjet and plasma profiling from DXF with machined weld preparations to your qualified procedure.
Verified phase balance
ASTM A923 Method B and C testing confirms freedom from sigma and chi intermetallic phases after rolling.
Technical Specifications
| Attribute | Details |
|---|---|
| Standards | ASTM A240 / A480 · ASME SA240 · EN 10088-2 (1.4410 / 1.4501) · NORSOK M-601 / M-630 |
| Grades Stocked | SDSS 2507 (S32750) · Zeron 100 (S32760) · Ferralium 255 (S32550) |
| Thickness Range | 2 mm to 60 mm |
| Width | 1000, 1250, 1500, 2000, 2500, 3000 mm |
| Length | 2000 to 12000 mm; cut to plan on request |
| Finish | 2B cold rolled · No.1 hot rolled annealed & pickled |
| Yield Strength | 550 MPa minimum (80 ksi) |
| Tensile Strength | 795–1000 MPa (115–145 ksi) |
| PREN | ≥ 40 (typical 41–43) |
| Ferrite Content | 35–55 % verified per ASTM E562 |
| Testing | ASTM G48 Method A at 50 °C · ASTM A923 · Charpy at –46 °C · UT per A578 · PMI |
| Certification | EN 10204 3.1 standard · 3.2 with TÜV, SGS, BV, Lloyd's or DNV witness |
Grade availability by thickness band
| Grade | UNS | 2–4 mm | 4–8 mm | 8–20 mm | 20–40 mm | 40–60 mm |
|---|---|---|---|---|---|---|
| SDSS 2507 | S32750 | |||||
| Zeron 100 | S32760 | — | ||||
| Ferralium 255 | S32550 | — | — | — | ||
| 2B cold rolled | S32750 | — | — | — |
Note: Thicknesses above 60 mm and clad plate are supplied against mill programmes on a 6–12 week lead time.
Use our free metal weight calculator — bars, sheets, plates, pipes and sections.
Grade chemistry and mechanical properties supplied in super duplex steel sheet & plate.
Chemical composition and mechanical properties are grade properties, not form properties — the same grade keeps the same chemistry whether it is supplied as sheet, plate or coil. The tables below list the specified limits for each grade we stock in super duplex steel sheet & plate, tested and certified to ASTM A240 / ASME SA240. Values are weight percent (maximum unless a range is shown); mechanical values are minima in the annealed condition.
Chemical composition (weight %)
| Grade | C | Cr | Ni | Mo | N | Cu | Mn | P | W |
|---|---|---|---|---|---|---|---|---|---|
| Super Duplex 2507UNS S32750 | 0.030 | 24.0–26.0 | 6.0–8.0 | 3.0–5.0 | 0.24–0.32 | 0.50 | 1.20 | 0.035 | — |
| Zeron 100UNS S32760 | 0.030 | 24.0–26.0 | 6.00–8.00 | 3.00–4.00 | 0.20–0.30 | 0.50–1.00 | 1.00 | — | 0.50–1.00 |
Balance iron. Single figures are maximum limits. Mill test certificates to EN 10204 3.1 are issued with every dispatch.
Mechanical properties (annealed, minimum)
| Grade | Tensile Strength (min) | Yield Strength (0.2%) | Elongation in 50 mm | Hardness (Rockwell C) | PREN |
|---|---|---|---|---|---|
| Super Duplex 2507 | 795 MPa (116 ksi) | 550 MPa (80 ksi) | 15% min | 32 max (NACE MR0175) | — |
| Zeron 100 | 750 MPa (109 ksi) | 550 MPa (80 ksi) | 25% min | — | 40 minimum |
Typical annealed values; actual results are stated on the heat-specific mill test certificate.
Application Sectors
Offshore Oil & Gas
Separator vessels, produced-water plant and topside piping supports.
Desalination
MSF and RO evaporator chambers, brine heaters and high-chloride vessels.
Marine & Shipbuilding
Chemical tanker cargo tanks and seawater ballast systems.
Chemical Processing
Acid and chloride process vessels beyond the limits of 904L.
Pulp & Paper
Bleach-plant washers and towers in chlorine dioxide service.
Power Generation
FGD absorbers, seawater condenser components and cooling systems.
Subsea
Structural plate for manifolds, protection structures and clamp bodies.
Heat Exchangers
Tube-sheets and channel covers machined from 20–60 mm plate.
Cut, finished and certified to your drawing.
Material leaves our Mumbai facility finished to your specification — not as raw stock.
Why buy from Steelco.
Steelco Metal & Alloys is a Mumbai-based stockist, importer and exporter of stainless steel and nickel alloys, shipping certified material worldwide.
Quality & testing on every dispatch
- EN 10204 3.1 mill test certificate on every dispatch
- 3.2 certification with TÜV / SGS / BV / Lloyd's / IRS / IBR witness on request
- Positive Material Identification (PMI) with portable XRF / OES
- Dye-penetrant (DPT), ultrasonic (UT) and hydro testing on request
- NACE MR0175 / ISO 15156 compliance for sour service
- PED 2014/68/EU compliance for pressure equipment
- Heat-number stencilling and marking for full traceability
Deep ready stock
Super duplex plate held in Mumbai in 2507 and Zeron 100 from 2 mm to 60 mm — cut, bevelled and dispatched with G48, A923 and NACE documentation, typically within 3–5 working days.
Mill-direct sourcing
Approved supply from Jindal, JSL, Outokumpu, Aperam, Acerinox, Sandvik and leading Japanese and Korean mills — every item traceable to a named producer.
Full certification
EN 10204 3.1 mill test certificate as standard, 3.2 with TÜV, SGS, BV, Lloyd's, IRS or IBR witness, plus PMI, DPT and UT reports on request.
On-time worldwide delivery
Regular export shipments to the GCC, Africa, Southeast Asia, Europe, Latin America and the USA via Nhava Sheva (JNPT), Mundra and Mumbai ports.
How your material is packed and shipped.
Every consignment leaves our Mumbai facility protected for transit and documented for customs, whether it moves by road within India or by sea to an overseas port.
Domestic & export packing
- Sheets interleaved with paper, PVC coated on 2B finishes
- Plates on hardwood skids with steel banding and corner protection
- VCI paper for long sea transit
- Heat number stencilled on every plate and offcut
Global shipments
- HS Code: 7219 (width ≥ 600 mm) · 7220 (width < 600 mm)
- FOB / CFR / CIF terms via Nhava Sheva (JNPT), Mundra and Mumbai ports
- Documentation: commercial invoice, packing list, MTC, bill of lading, COO, insurance
- Regular exports to the GCC, Africa, Southeast Asia, Europe, Latin America and the USA
Ready to price your requirement?
Share grade, size and quantity — our Mumbai desk responds with pricing, stock position and lead time, usually the same working day.
Frequently asked questions.
Answers to the questions our Mumbai desk is asked most often.
When is super duplex plate required instead of duplex 2205?
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When the chloride level and temperature exceed what a PREN of 35 can survive — typically warm seawater above 40 °C, RO brine, bleach-plant liquor and sour production fluids. Super duplex carries a PREN above 40 and a critical pitting temperature around 50 °C.
What is the maximum service temperature of super duplex plate?
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Around 250–300 °C. Longer exposure above that causes sigma-phase precipitation and a sharp loss of toughness, so nickel alloys such as Inconel 625 are used for higher temperatures.
How is super duplex plate welded?
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With matching ER2594 / E2594 consumables, heat input controlled between roughly 0.5 and 1.5 kJ/mm, interpass temperature below 150 °C, and a nitrogen-bearing backing gas. Ferrite and A923 checks confirm the finished weld.
Do you supply plate with G48 corrosion test reports?
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Yes. ASTM G48 Method A at 50 °C for 24 hours is standard on super duplex heats, together with ASTM A923 and ferrite counts to ASTM E562, all issued with EN 10204 3.1 or 3.2 certification.
Can you cut and bevel plate to our drawing?
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Yes. We waterjet and plasma cut from DXF, machine weld preparations to your qualified procedure, and stencil the heat number onto every cut piece.