Duplex and super duplex steel products are what engineers specify when 316 pits in seawater or 304 cracks in hot chloride service. Aashish Metals is a supplier and exporter of duplex and super duplex pipes, tubes, plates, sheets, round bars, flanges, fittings and fasteners, shipped from Mumbai with mill test certificates. Its structure is roughly half austenite and half ferrite. This combination gives it about twice the strength of standard stainless, and it resists chloride stress corrosion cracking, a known failure mode for 304 and 316. For the most challenging applications, such as offshore platforms, desalination plants and high-pressure chemical lines, there’s super duplex.
We supply both, including duplex pipes and tubes, super duplex pipes and tubes, plates and sheets, round bars, flanges, pipe fittings and fasteners. Everything comes with heat numbers and mill test certificates, and we’ll cut it to size if you need that.
Not sure whether 2205 will do or you need 2507? Give us details of what the line will carry, including temperature and pressure, and we’ll give you a straight response. Or request a quote and we will respond to you within [24 hours].
Duplex & Super Duplex Steel Products List
Pipes and Tubes
Seamless and welded pipe for seawater, process and pipeline duty. See duplex pipes and tubes (S31803/S32205) and super duplex pipes and tubes (S32750/S32760), or browse duplex and super duplex pipes and tubes.
Plates, Sheets and Coils
Flat products for pressure vessels, tanks and structural work: duplex plates, sheets and coils and super duplex plates, sheets and coils.
Round Bars
For shafts, pump and valve parts, and machined components: duplex round bars and super duplex round bars, cut to length.
Flanges (ASME B16.5, B16.47)
Weld neck, slip-on, blind, socket weld, threaded and lap joint flanges in ASME B16.5 classes, in in duplex F51 and F60 and super duplex F53 and F55. duplex and super duplex flanges.
Butt weld Pipe Fittings
Elbows, tees, reducers and caps in duplex and super duplex pipe fittings, plus grade-specific pages for duplex pipe fittings (F51, F60) and super duplex pipe fittings (F53, F55).
Socket weld and threaded fittings
Small-bore connections in duplex and super duplex socket weld fittings and threaded fittings. We also stock socket weld fittings in duplex F51 and F60 and super duplex F53 and F55.
Bolts, Studs and Nuts
Bolts, studs and nuts that hold up as well as the pipe they join: duplex fasteners and super duplex fasteners, including ASTM A182 F51, F53 and F55.
Tube fittings and instrumentation valves
Compression duplex and super duplex tube fittings for instrument lines, with duplex needle valves, manifold valves and ball valves. Super duplex versions: needle valves, manifold valves and ball valves.
Technical Data
Why Duplex and Super Duplex Steel Outperform 304 and 316
Duplex steels have a two-phase structure of austenite and ferrite in roughly equal parts. The austenite brings toughness and easy fabrication, and the ferrite brings strength and resistance to stress corrosion cracking. Super duplex simply pushes the chromium, molybdenum and nitrogen higher for tougher service.
| Feature | What it means for your project |
|---|---|
| About twice the yield strength of 304 and 316 | Thinner walls for the same pressure, so lighter pipework and lower material cost |
| High resistance to pitting and crevice corrosion | Reliable in seawater and chloride-rich process streams |
| Strong resistance to chloride stress corrosion cracking | Far fewer failures in hot, salty service than austenitic grades |
| Good toughness, including at low temperature | Retains impact toughness down to about −50 °C when impact testing is specified |
| Good weldability | Fabricates with standard methods when heat input and filler are controlled |
| Lower nickel content | More stable pricing than high-nickel alloys |
| Long service life | Lower lifetime cost, even where the upfront price is higher |
Duplex and Super Duplex Chemical Composition (% by weight)
| Element | Duplex S31803 | Duplex S32205 | Super duplex S32750 | Super duplex S32760 |
|---|---|---|---|---|
| Chromium (Cr) | 21.0 – 23.0 | 22.0 – 23.0 | 24.0 – 26.0 | 24.0 – 26.0 |
| Nickel (Ni) | 4.5 – 6.5 | 4.5 – 6.5 | 6.0 – 8.0 | 6.0 – 8.0 |
| Molybdenum (Mo) | 2.5 – 3.5 | 3.0 – 3.5 | 3.0 – 5.0 | 3.0 – 4.0 |
| Nitrogen (N) | 0.08 – 0.20 | 0.14 – 0.20 | 0.24 – 0.32 | 0.20 – 0.30 |
| Carbon (C) | 0.03 max | 0.03 max | 0.03 max | 0.05 max |
| Copper / Tungsten | – | – | Cu 0.5 max | Cu 0.5 – 1.0, W 0.5 – 1.0 |
| Manganese (Mn), max | 2.00 | 2.00 | 1.20 | 1.00 |
| Silicon (Si), max | 1.00 | 1.00 | 0.80 | 1.00 |
| Phosphorus (P), max | 0.030 | 0.030 | 0.035 | 0.030 |
| Sulphur (S), max | 0.020 | 0.020 | 0.020 | 0.010 |
| Iron (Fe) | Balance | Balance | Balance | Balance |
Limits per ASTM A790 and A182. Values shown are ranges or maximums unless marked typical.
Duplex and Super Duplex Mechanical Properties
| Property | S31803 | S32205 | S32750 | S32760 |
|---|---|---|---|---|
| Tensile strength (min) | 620 MPa | 655 MPa | 800 MPa | 750 MPa |
| Yield strength 0.2% (min) | 450 MPa | 450 MPa | 550 MPa | 550 MPa |
| Elongation (min) | 25% | 25% | 15% | 25% |
| PREN (typical) | 34 – 35 | 35 | 41 – 43 | 40 – 42 |
| Density | 7.8 g/cm³ | 7.8 g/cm³ | 7.8 g/cm³ | 7.8 g/cm³ |
| Hardness (max) | 290 HBW | 293 HBW | 310 HBW | [confirm vs A790] |
| Impact toughness | Per specification, tested on request | Per specification, tested on request | Per specification, tested on request | Per specification, tested on request |
Duplex and Super Duplex Equivalent Grades and Material Codes
| UNS number | Common names | Material code (ASTM A182) | EN / W.Nr. |
|---|---|---|---|
| S31803 | Duplex 2205 | F51 | 1.4462 |
| S32205 | Duplex 2205 | F60 | 1.4462 |
| S32750 | Super duplex 2507, SAF 2507 | F53 | 1.4410 |
| S32760 | Zeron 100 | F55 | 1.4501 |
Duplex and Super Duplex Standards and Specifications
| Product | Specification |
|---|---|
| Seamless and welded pipe | ASTM A790 |
| Tube | ASTM A789 |
| Plate, sheet and strip | ASTM A240 |
| Forged flanges and fittings | ASTM A182 |
| Bars | ASTM A276 / A479, EN 10088-3 |
| Butt weld fittings | ASTM A815 |
| Dimensions | ASME B36.19M, B16.5, B16.47, B16.9, B16.11 |
| Offshore specifications | NORSOK M-630 / M-650 where required |
| Optional testing | ASTM A923 (intermetallic phases), ASTM G48 Method A (pitting) |
| Fasteners | Machined from ASTM A276 / A479 bar or ASTM A182 forgings; dimensions per ASME B18.2.1 / B18.2.2 [confirm] |
| Condition and finish | Solution annealed. Hot rolled, cold drawn, pickled and passivated or polished, as ordered |
| Tolerances | Per ASTM, ASME and EN standards. Tighter tolerances and cut lengths on request |
Duplex and Super Duplex Size Range and Availability
| Product form | Size range | Schedule / thickness | Standard |
|---|---|---|---|
| Seamless pipe | [__ to __ inch NB] | [Sch 10S to XXS] | ASTM A790, ASME B36.19M |
| Welded pipe | [__ to __ inch NB] | [Sch __ to __] | ASTM A790 |
| Tube | [__ to __ mm OD] | [__ to __ mm wall] | ASTM A789 |
| Plate and sheet | [width × length] | [__ to __ mm] | ASTM A240 |
| Round bar | [__ to __ mm dia] | Cut to length | ASTM A276 / A479 |
| Flanges | [__ to __ inch] | Class 150 to 2500 [confirm] | ASME B16.5, B16.47 |
| Butt weld fittings | [__ to __ inch] | Sch [__] | ASTM A815, ASME B16.9 |
Sizes outside this range are quoted on request. Send the drawing or size list and we will confirm availability.
Applications of Super Duplex Steel Products
| Industry | Typical applications | Usual grade |
|---|---|---|
| Oil and gas, offshore | Flowlines, risers, manifolds, topside seawater and firewater piping | 2507, Zeron 100 |
| Chemical processing | Heat exchangers, pressure vessels, reactors, storage tanks | 2205, 2507 |
| Desalination | High-pressure RO piping, brine heaters, evaporators | 2507 |
| Marine and shipbuilding | Shafts, propeller parts, chemical tanker cargo tanks, ballast lines | 2205, 2507 |
| Pulp and paper | Digesters, bleaching equipment, liquor tanks | 2205 |
| Power generation | Flue gas desulphurisation (FGD) scrubbers, cooling water lines | 2205, 2507 |
| Mining and mineral processing | Slurry pipelines, leaching tanks, pumps | 2205 |
| Construction and bridges | Load-bearing structures, reinforcement in coastal zones | 2205 |
| Fertiliser and urea plants | Strippers, pipework, high-pressure lines | 2205, 2507 |
Duplex 2205 vs Super Duplex 2507 vs 316L Stainless Steel
This is the question most buyers ask first, so here is the short answer in a table.
| Criteria | 316L stainless | Duplex 2205 | Super duplex 2507 |
|---|---|---|---|
| Structure | Austenitic | Austenitic-ferritic | Austenitic-ferritic |
| Yield strength (min) | About 170 MPa | About 450 MPa | About 550 MPa |
| PREN (typical) | About 24 | About 35 | About 41 – 43 |
| Chloride pitting resistance | Limited | Good | Excellent |
| Chloride stress corrosion cracking | Susceptible | Very good | Excellent |
| Magnetic | No (annealed) | Yes | Yes |
| Suggested upper temperature | Higher | About 250 °C | About 300 °C |
| Cost | Lowest | Moderate | Higher |
| Best for | Mild, low-chloride service | Most seawater, process and structural use | Severe chloride, high-pressure and offshore service |
Which one should you pick? For general process and marine work, 2205 gives you the best balance of cost and performance. Step up to 2507 or Zeron 100 when chlorides, temperature or pressure are severe. If the environment is mild, 304 or 316L may be enough, and if it is severe enough for acids and hot brine, consider Hastelloy, Inconel, titanium or our wider nickel alloy range. For seawater lines, copper nickel is another option.
Certifications, Standards and Documentation
| Document or standard | What it covers |
|---|---|
| Mill test certificate, EN 10204 3.1 | Heat number, chemistry, mechanical results |
| EN 10204 3.2 (on request) | Certificate countersigned by an independent inspector |
| PMI report | Alloy composition check |
| ASTM A923 / G48 reports (on request) | Freedom from harmful phases and pitting performance |
| NACE MR0175 / ISO 15156 | Sour-service suitability, where specified |
| ASTM, ASME and EN standards | A790, A789, A240, A182, A276, A479, A815, B16.5, B16.9 |
| Third-party inspection | Arranged with your nominated agency |
How We Supply and Inspect Duplex and Super Duplex Steel
Duplex steels only deliver their strength and corrosion resistance if the ferrite-austenite balance is right, and poor heat treatment can quietly ruin it. So we check the material at each stage, from mill certificate to dispatch.
flowchart LR
A[Your enquiry] –> B[Grade and spec check]
B –> C[Sourcing from approved mills]
C –> D[Incoming inspection]
D –> E[Cutting and preparation]
E –> F[Final check and packing]
F –> G[Dispatch with MTC]
- Grade and spec check. We confirm the UNS number, standard, size and any project specification such as NORSOK before quoting.
- Approved sourcing. Material comes from reputable mills that supply solution-annealed, traceable product.
- Incoming inspection. Dimensions, surface, markings and positive material identification (PMI) checks on every lot.
- Cutting and preparation. Sawing, bevelling or machining to drawing, with clean tools to avoid contamination.
- Testing on request. ASTM A923 for harmful phases, ASTM G48 Method A pitting test, ferrite measurement, hydrostatic and ultrasonic testing, as your specification requires.
- Packing and dispatch. Marked with grade and heat number, packed for export, with complete documents.
FAQ’s About Super Duplex Steel Products
The price of super duplex steel varies based on grade, product form, size, quantity and current raw material costs. Contact us for the latest price based on your exact requirement.
UNS S32750 is a super duplex stainless steel grade, commonly known as 2507. It offers high strength along with excellent resistance to chloride corrosion and stress corrosion cracking.
Super duplex steel generally contains higher chromium, molybdenum and nitrogen than standard duplex grades. This provides higher strength and improved resistance to pitting, crevice corrosion and chloride environments.
Yes, super duplex stainless steel is magnetic because it contains a significant ferritic phase. Its magnetic response is generally stronger than that of fully austenitic stainless steel.
Common super duplex grades include UNS S32750 (2507) and UNS S32760. The applicable material code depends on the grade and product standard specified for the application.
The hardness of duplex stainless steel varies by grade, product form and heat treatment. For many duplex grades, hardness is commonly specified around 250 HB or higher, subject to the applicable material standard.
Need Duplex or Super Duplex Steel? Get Your Quote Today
Tell us the grade (2205, 2507, Zeron 100 or another), product form, size and quantity, and we will come back with pricing and availability, usually within [24 hours]. Not sure which grade is right? Describe your fluid, temperature and pressure and we will help you decide.
For More Information About Duplex and Super Duplex Stainless Steel Products please call +91-22-66362223 / 66394926 or send an email to export@aashishmetal.com
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