Super Duplex Stainless Steel is a high-alloy stainless steel designed for use in highly aggressive and corrosive environments. It features a balanced microstructure of approximately 50% austenite and 50% ferrite, providing exceptional strength and superior corrosion resistance.
Compared to standard duplex grades, Super Duplex offers significantly enhanced resistance to pitting, crevice corrosion, and chloride-induced stress corrosion cracking, making it a preferred material for critical applications in offshore, marine, chemical, and process industries.
Key Advantages of Super Duplex Stainless Steel
Exceptional Mechanical Strength
Super Duplex stainless steel provides approximately twice the yield strength of conventional austenitic stainless steels and higher strength than standard duplex grades. This allows for reduced wall thickness, lower weight, and improved structural efficiency.
Outstanding Corrosion Resistance
Super Duplex is specifically engineered to perform in environments where conventional stainless steels may fail.
It offers excellent resistance to:
- Pitting corrosion
- Crevice corrosion
- Chloride attack
- Stress corrosion cracking
- Erosion corrosion
Reliable Performance in Extreme Environments
Super Duplex maintains its integrity and performance in seawater, offshore platforms, desalination systems, and highly aggressive chemical processing environments.
Long Service Life
Its superior resistance to corrosion and mechanical wear helps minimise maintenance costs and extends equipment lifespan.
Cost-Effective Lifecycle Performance
Although the initial material cost may be higher, the reduced maintenance, improved durability, and extended service life often result in lower overall ownership costs.
Super Duplex 2507
Super Duplex 2507 (UNS S32750) is the most widely used Super Duplex stainless steel grade.
It is recognised worldwide for its combination of:
- Exceptional corrosion resistance
- High mechanical strength
- Excellent durability
- Long-term reliability in extreme service conditions
Typical Applications
- Offshore oil and gas platforms
- Seawater piping systems
- Desalination plants
- Heat exchangers
- Pressure vessels
- Chemical processing equipment
- Firewater systems
- Marine and shipbuilding applications
- Subsea equipment
| Typical Mechanical Properties | |
|---|---|
| Property | Super Duplex 2507 |
| Yield Strength | ≥ 550 MPa |
| Tensile Strength | 800–1000 MPa |
| Elongation | ≥ 15% |
| Hardness | ≤ 310 HB |
| Density | 7.8 g/cm³ |
| Values are typical and may vary according to product form and specification. | |


