Duplex · UNS S32205
2205 Stainless Steel
2205 is a duplex stainless steel — roughly half austenite and half ferrite — that combines about twice the yield strength of 316L with better chloride and stress-corrosion resistance. It is the answer when 316L is not strong enough or not corrosion-resistant enough, and the cost sits between 316L and super-austenitics.
Quote within 24 working hours · Certificate type stated on the quote
Duplex · UNS S32205 · 7.80 g/cm³
At a glance
2205 Stainless — The Short Version
| Alloy family | Duplex (UNS S32205) |
|---|---|
| Density | 7.80 g/cm³ |
| Standards | ASTM A240 · EN 10088-2 · ASTM A790 (pipe) |
| Forms supplied | Stainless Steel Sheet & Plate · Stainless Steel Tube & Pipe · Stainless Steel Bar & Rod · Stainless Steel Fittings & Flanges |
Chemistry
2205 Chemical Composition Limits
Percent by weight. These are the registered limits, not a typical analysis — a heat that sits anywhere inside them is still 2205.
| Element | Limit (% wt) | Element | Limit (% wt) |
|---|---|---|---|
| C | 0.030 max | Mn | 2.00 max |
| P | 0.030 max | S | 0.020 max |
| Si | 1.00 max | Cr | 22.0 – 23.0 |
| Ni | 4.5 – 6.5 | Mo | 3.0 – 3.5 |
| N | 0.14 – 0.20 |
Composition limits are the ASTM A240 registered ranges, which EN 10088-2 refers back to. Mechanical values are typical for the solution-annealed condition, not acceptance minima — the minima are set by the product standard, and the mill certificate reports the measured values for your heat.
Mechanicals
Typical Mechanical Properties (Solution Annealed)
Room temperature. Use these to compare grades — the acceptance figures for your order come from the product standard and are reported on the mill certificate for the actual heat.
| Condition | Tensile (MPa) | Yield (MPa) | Elongation (%) |
|---|---|---|---|
| Annealed | 620 | 450 | 25 |
Cold-worked tempers are available to order — values are quoted with the offer rather than assumed from this table.
Forms
2205 in the Forms We Supply
The same grade behaves differently as coil, plate and tube because the forming route sets the surface and the final mechanical condition. Pick the form first.
Stainless Steel Sheet & Plate
Cold-rolled sheet and hot-rolled plate for structural and decorative use.
0.3 – 120 mm · 1,000 – 2,000 mm
Stainless Steel Tube & Pipe
Seamless and welded round, square and rectangular tube.
Wall 0.5 – 40 mm · OD 6 – 630 mm
Stainless Steel Bar & Rod
Round, flat, square and hexagonal bar, cold drawn or hot rolled.
Ø 3 – 600 mm · —
Stainless Steel Fittings & Flanges
Elbows, tees, reducers, flanges, fasteners and custom fabricated parts.
DN 15 – DN 600 · —
Selection
Choose 2205 When — and When Not To
Choose 2205 when
Chemical tanks, desalination and seawater systems, pressure vessels, and structural applications where the part is both load-bearing and chloride-exposed. The higher yield lets the designer use thinner section than 316L for the same load.
Think again if
Simple indoor or mildly corrosive service where 304 or 316L is cheaper and easier to fabricate. Duplex needs more care in welding and forming, and the premium is only justified when the strength or corrosion combination is actually needed.
Before you ask
2205 — Questions Buyers Ask
How much stronger is 2205 than 316L?
Roughly twice the yield strength — around 450 MPa against 316L's 170 MPa. That is the reason a designer can cut wall thickness and still carry the same load.
What is 2205 PREN?
Around 34–35, well above 316L's 24–26. It is the number behind choosing 2205 for seawater and high-chloride duty.
Is 2205 harder to weld?
Yes — duplex needs controlled heat input and interpass temperature, and the filler is usually 2209. The weld is fully doable but it is not the same relaxed procedure as 316L.
Where is 2205 worth the cost?
Load-bearing chloride service: chemical storage, desalination, offshore and structural marine. If the part is not both stressed and chloride-exposed, a cheaper grade usually does the job.
Also compare
Other Stainless Grades
- 304 Stainless SteelAustenitic · UNS S30400
- 316L Stainless SteelAustenitic · UNS S31603
- 304L Stainless SteelAustenitic · UNS S30403
- 316 Stainless SteelAustenitic · UNS S31600
- 201 Stainless SteelAustenitic · UNS S20100
- 430 Stainless SteelFerritic · UNS S43000
- 321 Stainless SteelAustenitic · UNS S32100
- 310S Stainless SteelAustenitic · UNS S31008
- All stainless grades →The full stainless grade map
Quote on 2205 Stainless Steel
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