Materials / Grade-critical stainless
Duplex 2205
- UNS
- S32205
- W.Nr
- 1.4462
- EN
- X2CrNiMoN22-5-3
The workhorse duplex stainless: roughly twice the yield strength of 316L with far better chloride stress-corrosion cracking resistance, at a lower nickel cost.
Composition
| Element | Min | Max |
|---|---|---|
| Cr | 22.0 | 23.0 |
| Ni | 4.5 | 6.5 |
| Mo | 3.0 | 3.5 |
| N | 0.14 | 0.20 |
| Mn | — | 2.0 |
| C | — | 0.030 |
| S | — | 0.020 |
| Fe | — | bal |
Per cent by weight, to the governing standard.
- Fe68.8
- Cr22.5
- Ni5.5
- Mo3.3
Per cent by weight, at the midpoint of each specified window. Elements given only as a maximum have no midpoint to take, so they sit inside the balance rather than being estimated; trace elements below 0.5 % are not shown. Indicative only; the composition table above and the governing standard are what define the limits.
Mechanical
- Tensile strength, min
- 655 MPa
- Yield strength (0.2%), min
- 450 MPa
- Elongation, min
- 25 %
- Ferrite content
- Typically 35–55 %
Standards by form
| Plate, sheet & strip | ASTM A240 | |
|---|---|---|
| Pipe & tube | ASTM A790 / A928 | |
| Forgings & fittings | ASTM A182 / A815 | |
| Bar | ASTM A276 / A479 |
Where it is specified
- Process piping, pressure vessels and tanks in chloride service
- Marine, desalination, oil and gas gathering systems
- PREN typically 34 or above
The wider S31803 windows still ship against 2205 orders
The older S31803 designation has wider composition windows than S32205 and is still supplied against 2205 orders. As with all duplex, the real risk is structural: a bad anneal leaves sigma phase and a ferrite balance out of range while the chemistry certificate reads perfectly.
What we specify and check
- Confirmation of S32205 rather than the wider S31803 windows
- Ferrite content measured on the delivered material
- PREN calculated from measured values
- ASTM A923 testing for intermetallic phase where specified
We commission an accredited independent laboratory to test the heat before the material leaves China. You will receive that report unedited, whether it passes or not.
Request Duplex 2205
Tell us the form, dimensions and service conditions. We reply with availability, indicative landed price, lead time and the test regime we would specify for your application.
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