Super Duplex Steel
Super duplex 2507 (UNS S32750), Zeron 100 (S32760) and F55 in sheet, plate, bar, pipe, tube, flange, fitting and forged-ring form — ASTM A240 / A790 / A182 F53 with 3.1 / 3.2 MTC.
What is super duplex steel?
Super duplex stainless steel is a duplex grade with a pitting resistance equivalent number (PREN) above 40, achieved with roughly 25% chromium, 4% molybdenum, 7% nickel and 0.24–0.32% nitrogen. Grades 2507 (UNS S32750) and Zeron 100 (S32760, ASTM F55) deliver 550 MPa minimum yield strength and resist chloride pitting, crevice attack and stress-corrosion cracking in seawater and sour service.
Steelco Metal & Alloys stocks super duplex in Mumbai in plate, sheet, round bar, seamless and welded pipe, tube, ASTM A182 F53 / F55 flanges, buttweld fittings and rolled rings, supplied solution annealed with ferrite balance, impact and corrosion (ASTM G48) test reports on request. Every dispatch leaves our Mumbai warehouse with an EN 10204 3.1 mill test certificate (3.2 with TUV, SGS, BV, Lloyd's, IRS or IBR witness on request), PMI verification and full heat-number traceability.
Super duplex grades we stock.
Open a grade for chemistry, PREN, mechanical properties, equivalents and stocked sizes.
Super Duplex Steel we hold in ready stock.
Plate & sheet
2 – 100 mm to ASTM A240 UNS S32750 / S32760, hot- and cold-rolled.
Round bar
Ø 8 – 450 mm to ASTM A276 / A479 F53, forged, peeled and ground.
Seamless & welded pipe
1/2" – 24" NB to ASTM A790 / A928, Sch 10S to Sch 160.
Tube
Ø 6 – 219 mm heat-exchanger and umbilical tube to ASTM A789.
Flanges
ASTM A182 F53 / F55 flanges 1/2" – 36", Class 150 – 2500.
Fittings, rings & fasteners
B16.9 fittings, rolled rings to Ø 3000 mm, studs and nuts to NACE.
Use our free metal weight calculator — bars, sheets, plates, pipes and sections.
Our super duplex range
Ready stock across every mainstream form — dispatched with mill test certificates and full traceability from our Mumbai warehouse.
Sheet & Plate
2 – 100 mm, ASTM A240 S32750 / S32760.
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Round Bar
Ø 8 – 450 mm, ASTM A276 / A479 F53.
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Pipe & Fittings
Seamless and welded 1/2" – 24" NB.
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Tube
Heat-exchanger and umbilical tube.
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Flanges
ASTM A182 F53 / F55, Class 150 – 2500.
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Rolled rings to Ø 3000 mm.
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Fasteners
F55 studs, bolts and nuts to NACE MR0175.
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Welding Consumables
ER2594 wire and E2594 electrodes.
ExploreSuper Duplex Steel specifications.
Standards, sizes, thickness and condition we routinely supply across every product form.
| Product | Size Range | Thickness / Wall | Finish / Condition | Standards |
|---|---|---|---|---|
Plate | 1000 – 3000 mm wide | 3 – 100 mm | Hot-rolled, annealed & pickled | ASTM A240 / ASME SA240 |
Sheet | 1000 – 2000 mm wide | 2 – 6 mm | 2B, cold-rolled | ASTM A240 / EN 10088-2 |
Round Bar | Ø 8 – 450 mm | — | Black, peeled, ground, forged | ASTM A276 / A479 / A182 F53 |
Seamless Pipe | 1/2" – 12" NB | Sch 10S – Sch 160 | Annealed & pickled | ASTM A790 |
Welded Pipe | 1/2" – 24" NB | Sch 5S – Sch 40S | Annealed & pickled | ASTM A928 / A790 |
Flanges | 1/2" – 36" | Class 150 – 2500 | Forged, RF / RTJ | ASTM A182 F53 / F55 |
Note: G48 Method A corrosion testing and Charpy impact at -46 °C available on request.
Where super duplex steel is used.
Subsea & Offshore
Manifolds, jumpers, umbilicals and christmas-tree components in F55.
Desalination
High-pressure RO piping, energy recovery and brine systems in 2507.
Oil & Gas
Sour-service flowlines, valve bodies and separator internals to NACE MR0175.
Chemical Tankers
Cargo tanks, deepwell pumps and cargo piping.
Power & FGD
Seawater cooling systems and flue gas desulphurisation absorbers.
Mining & Minerals
Slurry pipework, autoclave internals and acid leaching circuits.
Frequently asked questions.
Answers to the questions our Mumbai desk is asked most often.
What is the PREN of super duplex 2507?
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Super duplex 2507 (UNS S32750) has a PREN of 42–43, calculated as %Cr + 3.3 × %Mo + 16 × %N from nominally 25% Cr, 4% Mo and 0.28% N. Zeron 100 (S32760) reaches PREN 40 minimum with added copper and tungsten. Both resist pitting in seawater to a critical pitting temperature above 50 °C.
What is the difference between F53 and F55?
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F53 is the ASTM A182 forging designation for UNS S32750 (2507) and F55 for UNS S32760 (Zeron 100). F55 adds around 0.7% copper and 0.7% tungsten, which improves resistance in reducing acids and is often specified for subsea and seawater-injection duty.
Can super duplex be used above 300 °C?
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No. Super duplex should be limited to about 250–300 °C in continuous service. Above that, 475 °C embrittlement and sigma-phase precipitation degrade toughness. For higher temperatures use an austenitic grade such as 321, 347H or a nickel alloy.
Do you supply super duplex with G48 corrosion test reports?
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Yes. ASTM G48 Method A ferric chloride pitting tests, ferrite content measurement per ASTM E562, and Charpy V-notch impact testing at -46 °C are arranged with third-party witness where the project specification calls for them.
Every dispatch is traceable, tested and certified.
Material is supplied with EN 10204 3.1 (3.2 on request) mill test certificates, PMI and spectro verification, and is open to third-party inspection by TUV, SGS, BV, Lloyd’s and IRS from our Mumbai warehouse.
EN 10204 3.1 / 3.2
Mill test certificate with every consignment.
PMI & Spectro
Positive material identification before dispatch.
Third-party Inspection
TUV · SGS · BV · Lloyd's · IRS welcome.
Export Documentation
Full set prepared for 40+ countries.
Other grades you may also need
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