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Duplex 2205 Stainless Steel | S31803 / S32205 / F51 Supplier & Stockist
E Steel Sdn. Bhd. is the leading supplier of Duplex 2205 stainless steel (S31803, S32205, F51, EN 1.4462) in Malaysia, supplying customers across Selangor, Kuala Lumpur, Johor, Penang, and Singapore, and exporting to Indonesia, Brunei, Thailand, and other ASEAN countries.
We stock both Duplex 2205 plates and round bars / rods / shafts, and we don't only supply full plate or full-length bar — we offer precision bandsaw cut-to-size service, so you only pay and carry away the dimensions you actually need.
No minimum order (MOQ) required.
What Is Duplex 2205 / S31803 Stainless Steel?
Duplex 2205 is the most widely used duplex (ferritic/austenitic) stainless steel grade worldwide.
Its dual-phase microstructure — roughly equal parts ferrite and austenite — gives it a combination that neither phase offers alone: excellent corrosion resistance together with high strength, with a yield strength roughly double that of standard austenitic grades like 304 and 316.
2205 cannot be hardened by thermal treatment, but strength and hardness can be increased substantially by cold working, with a corresponding reduction in ductility. It is used extensively across the marine, chemical, petrochemical, pulp and paper, oil and gas, transport, and general processing industries — often as a direct upgrade over standard austenitic grades in more demanding environments.
S31803 vs S32205 — What's the Difference?
The standard duplex S31803 composition has, over the years, been refined by steel producers, and the resulting restricted composition range was formally endorsed as UNS S32205 in 1996. S32205 offers better guaranteed corrosion resistance through its tighter compositional control, but much of the S31803 currently produced already complies with S32205 limits as well. In practice, the two designations are frequently used interchangeably in the market, and material is commonly dual-certified to both.
Grade Equivalents — All the Ways Customers Search for Duplex 2205
Customers often search using different national standards, trade names, or specification codes.
The table below covers common equivalents:
| Standard / Reference | Designation |
|---|---|
| American UNS | S31803 / S32205 |
| Trade Name | 2205 Duplex / SAF 2205 |
| Forged Bar Designation | F51 |
| German (DIN / W.Nr) | 1.4462 / X2CrNiMoN22-5-3 |
| European (EN) | EN 1.4462 |
| Japanese (JIS) | SUS329J3L |
| American (ASTM) | ASTM A276-98b, ASTM A240 (plate), ASTM A182 F51 (forgings/bar) |
Our Duplex 2205 Plate & Round Bar Stock — Origin & Sizes
We stocked Duplex 2205/S31803 plates and round bars,
so customers can choose based on certification, budget, or origin preference:
| Parameter | Details |
|---|---|
| Plate Thickness | To be confirmed — please check current stock range with us Minimum size of Duplex Stainless Steel Plate is thk3mm |
| Round Bar Diameter | To be confirmed — please check current stock range with us. Minimum size of Duplex Stainless Steel Round Bar is DIA 10mm |
| Origin Mill | Europe & Japan |
| Form Supplied | Full plate or full-length bar, or bandsaw cut-to-size to your cutting list |
| Mill Test Certificate | 3.1 MTC per EN 10204 |
Need a size not listed? Call or WhatsApp us — we source non-standard diameters through our global procurement network with short lead times.
Bandsaw Cutting vs Plasma / Laser Cutting for Duplex 2205
A common question from customers: "Why not just plasma cut or torch cut my Duplex 2205 plate or bar?"
Flame cutting methods are fast, but duplex 2205 is a grade defined by a precisely balanced two-phase microstructure — and that balance is exactly what heat can disturb.
| Factor | Bandsaw Cutting (Cold Cut) | Plasma / Laser / Torch / Abrasive Cutting (Thermal or Friction Cut) |
|---|---|---|
| Heat-Affected Zone (HAZ) | None — material stays cold throughout the cut | Present — heat at the cut edge can locally shift the ferrite/austenite phase balance |
| Risk of Embrittlement | None — duplex 2205's known embrittlement risk in the 300–650°C range is never triggered by a cold cut | Localised heating can pass through embrittling temperature ranges at the cut edge, even briefly |
| Cut Surface Finish | Clean, straight, minimal burr | Dross, discoloration, oxide scale often present, needing secondary cleaning |
| Post-Processing Needed | Usually ready for machining or welding directly | Often requires grinding/deburring before use |
| Precision on Thick Sections | Consistent accuracy across the thickness/diameter range | Heat distortion/warping risk increases with section size |
| Suitability for Critical Industries | Preferred for oil & gas, marine, and petrochemical fabrication | Higher risk of edge integrity issues for these applications |
In short: Duplex 2205's core value proposition — its balanced two-phase microstructure delivering both strength and corrosion resistance — depends on avoiding uncontrolled heat exposure.
Bandsaw cold-cutting avoids this entirely, which is why we recommend it as the default method for Duplex 2205 plate and round bar, particularly for oil & gas, marine, and other critical fabrication.
Chemical Composition of Duplex 2205 / S31803 Stainless Steel
| Element | Min. % | Max. % |
|---|---|---|
| Carbon (C) | — | 0.03 |
| Silicon (Si) | — | 1.00 |
| Manganese (Mn) | — | 2.00 |
| Nickel (Ni) | 4.50 | 6.50 |
| Chromium (Cr) | 21.00 | 23.00 |
| Molybdenum (Mo) | 2.50 | 3.50 |
| Nitrogen (N) | 0.08 | 0.20 |
| Phosphorus (P) | — | 0.03 |
| Sulphur (S) | — | 0.02 |
Mechanical Properties of Duplex 2205 / S31803
Minimum Requirements (UNS S31803)
| Tensile Strength (MPa) Min | 0.2% Yield Strength (MPa) Min | Elongation in 50mm (%) Min | Hardness HB Max |
|---|---|---|---|
| 620 | 448 | 25 | 290 |
Corrosion Resistance of Duplex 2205 / S31803
| Corrosion Type | Performance vs Austenitic Grades |
|---|---|
| General Corrosion | Superior resistance in most media compared to SS316L or SS317L |
| Stress Corrosion Cracking | Much higher resistance compared to SS304L or SS316L |
| Pitting Corrosion | Higher resistance compared to SUS316L or SUS317L |
| Crevice / Erosion Corrosion | Higher resistance compared to SUS316L |
| Corrosion Fatigue | Better fatigue strength in corrosive environments than standard austenitic grades, due to higher strength combined with higher corrosion resistance |
Heat Treatment, Machining & Welding
Annealing
Heat to 1020–1100°C, hold until temperature is uniform throughout the section (approximately 30 minutes per 25mm of section as a guide), then quench in water for optimum corrosion resistance.
Machining
The machinability of S31803 in the annealed as-supplied condition is lower than SUS304 or SUS316, due to its approximately double yield strength — typically around 80% as machinable as standard SUS304/SUS316, and lower still against improved-machinability 304/316 variants. All machining should follow tooling manufacturer recommendations for feeds, speeds, and tool type suited to duplex grades.
Welding
Duplex 2205 is readily weldable by standard electric arc welding processes. Oxyacetylene welding is not recommended, due to the risk of carbon pick-up in the weld area.
Applications of Duplex 2205 / S31803
- Anchor guides
- Conveyors
- Fasteners and bushings
- High-strength pump shafts
- Propeller shafts
- Marine, chemical, petrochemical, pulp and paper, oil and gas equipment
- Various components currently using standard austenitic stainless steel grades where higher strength or corrosion resistance is needed
Why Choose E Steel for Your Duplex 2205 Plates & Round Bars?
✅ Stockist in Malaysia
Our Duplex 2205 plates and round bars are held at our Klang warehouse, ready to cut and deliver.
We will ship it in the fastest lead time from overseas warehouse too.
✅ Serving Malaysia & Singapore + Southeast Asia Markets
We supply and export to Singapore, Indonesia, Brunei, Thailand, and other ASEAN countries.
✅ Plate or Round Bar, Full Size or Cut to Size — Your Choice
Order full plate or full-length bar, or send us your cutting list and we bandsaw cut it to your exact dimensions.
✅ No Minimum Order Quantity (MOQ)
Whether you need one piece cut to size or a full plate/bar, we accommodate all order sizes — ideal for prototyping, R&D, and small-batch production.
✅ Material Traceability
Every plate or bar comes with a Mill Test Certificate (MTC) traceable to the original mill.
Frequently Asked Questions for Duplex 2205 S31803 F51 Stainless Steel
Q: Is S31803 the same as S32205 and F51?
They're closely related. S32205 is a tighter, more restricted composition range within the S31803 family, formally endorsed in 1996 for better guaranteed corrosion resistance — much material produced to S31803 also complies with S32205. F51 is the forged bar designation for essentially the same alloy family, commonly referred to together as "2205 Duplex."
Q: What is the difference between Duplex 2205 and S32205?
"2205" and "SAF 2205" are trade/common names for the same alloy family that S31803 and S32205 formally designate. In everyday sourcing conversations, these terms are used interchangeably.
Q: What is the EN/DIN equivalent of Duplex 2205?
EN 1.4462 (also written as DIN 1.4462 or X2CrNiMoN22-5-3) is the European designation equivalent to S31803/S32205.
Q: What is the JIS equivalent of Duplex 2205?
SUS329J3L is the Japanese JIS designation equivalent to S31803/S32205 duplex stainless steel.
Q: Why choose Duplex 2205 over 316L stainless steel?
Duplex 2205 offers roughly double the yield strength of 316L, along with superior resistance to general corrosion, stress corrosion cracking, pitting, and crevice/erosion corrosion — making it a common upgrade path for demanding marine, chemical, and oil & gas applications.
Q: What temperature range is Duplex 2205 suitable for?
Duplex 2205 is generally not recommended for continuous service above 300°C, due to embrittlement risk, nor below -50°C, due to a ductile-to-brittle transition. It performs best in the temperature range between these limits.
Q: Is Duplex 2205 easy to machine?
It is lower machinability than standard 304/316, at roughly 80% as machinable, due to its approximately double yield strength. Machining should follow tooling recommendations suited to duplex grades.
Q: Can Duplex 2205 be welded?
Yes, it is readily weldable by standard electric arc welding processes. Oxyacetylene welding is not recommended due to carbon pick-up risk in the weld area.
Q: Why do you recommend bandsaw cutting over plasma, laser, or torch cutting for Duplex 2205?
Bandsaw cutting is a cold-cutting process, so it creates no heat-affected zone and does not risk disturbing the balanced ferrite/austenite phase ratio that gives Duplex 2205 its strength and corrosion resistance. Thermal and friction cutting methods generate heat that can locally shift this balance and typically require secondary cleaning or grinding.
Q: Can you provide Mill Test Certificates (MTC)?
Yes. All our Duplex 2205 plates and round bars come with 3.1 MTCs traceable to the original mill, compliant with EN 10204.
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