Metals & alloys · Ferrous alloys
2507 super duplex stainless steel
A high-alloy duplex stainless steel designed for severe chloride environments, combining high strength with strong pitting, crevice-corrosion and stress-corrosion resistance.
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01
Overview
- Material class
- Metals & alloys
- Category
- Ferrous alloys
- Family
- Duplex Stainless Steel
- Product forms
- Sheet/plate, Bar/rod
Composition
| Constituent | Min | Max | Typical | Note |
|---|---|---|---|---|
| Cr | 24 | 26 | 25 | |
| Ni | 6 | 8 | 7 | |
| Mo | 3 | 5 | 4 | |
| N | 0.24 | 0.32 | 0.27 | |
| C | 0.03 | 0.02 | ||
| Fe | Balance |
02
Properties and conditions
Engineering properties
| Property | Value | Unit | Condition |
|---|---|---|---|
| Density | 7.8 | g/cm³ | Representative; verify product form and condition |
| Elastic modulus | 200 | GPa | Representative; verify product form and condition |
| Yield strength | ≥550 | MPa | annealed plate typical minimum |
| Tensile strength | 795–1000 | MPa | Representative; verify product form and condition |
| Elongation | ≥15 | % | Representative; verify product form and condition |
| PREN | >40 | nominal chemistry |
Conditions
Solution annealed
Balanced super-duplex reference condition.
Welded / HAZ reference
Welded condition; phase balance and intermetallic precipitation require control.
03
Processing and use
Processing
- Heat input and interpass temperature must preserve ferrite–austenite balance.
- Rapid cooling limits sigma and chi phase formation.
Applications
- Seawater piping
- Heat exchangers
- Desalination systems
- Offshore umbilicals
Selection considerations
- Avoid prolonged exposure in the intermetallic precipitation range.
- Weld procedure qualification and ferrite control are essential.
Open in an analysis tool
04
Standards and related materials
Standards and designations
| System | Designation | Note |
|---|---|---|
| UNS | S32750 | |
| EN | 1.4410 | |
| ASTM | A240 / A790 / A182 | product dependent |
05
Sources and context
Sources
- Alleima SAF 2507 technical dataExisting reference
- Outokumpu super duplex dataExisting reference
- U.S. Department of Energy critical materials programStrategic reference
Confirm the applicable specification, product form and condition before using values for design or procurement.
Supply and sustainability
Available from specialist stainless mills; product-form and welding-consumable availability should be checked early.
High strength can reduce material mass; alloying intensity makes recycling and long service life important.
Strategic context
Enables thinner-wall corrosion-resistant equipment in offshore, desalination and chemical service.
Critical inputs: Nickel, Molybdenum
Basis: EU Critical Raw Materials Act (2024); USGS 2025 Critical Minerals List