SuperDuplex stainless like Duplex, is a mixed microstructure of austenite and ferrite (50/50) which has improved strength over ferritic and austenitic steel grades. The main difference is that Superduplex has a higher Molybdenum and Chromium content which gives the material greater corrosion resistance.
SuperDuplex has the same benefits as its counterpart – it has lower production costs when compared with similar ferritic and austenitic grades and due to the materials increased tensile and yield strength, in many cases this gives the purchaser the welcomed option of purchasing smaller thicknesses without the need to compromise on quality and performance.
Benefits of UNS32750 SuperDuplex Stainless Steel
- Improved corrosion resistance in comparison to Duplex
- Greater tensile and yield strength
- Good ductility and toughness
- Good stress corrosion cracking resistance (SSC)
- Opportunity for purchases to reduce their material costs without compromising on quality
Applications
SuperDuplex is used in the oil and gas industry, on offshore platforms, in heat exchangers, chemical processing equipment pressure vessels and boilers.
- Oil and gas industry equipment
- Offshore platforms, heat exchangers, process and service water systems, fire-fighting systems, injection and ballast water systems
- Chemical process industries, heat exchangers, vessels, and piping
- Desalination plants, high pressure RO-plant and seawater piping
- Mechanical and structural components, high strength, corrosion-resistant parts
- Power industry FGD systems, utility and industrial scrubber systems, absorber towers, ducting, and piping
About UNS32750
2507 is the most common Super Duplex alloy which contains 24% chromium and a minimum of 3% molybdenum. Please refer to the chemical composition and mechanic properties tables below. For information on Duplex alloy please click here.
Chemical Composition of S32750
| UNS No | S32750 |
|---|---|
| EN | 1.441 |
| AISI | 2507 |
| Carbon (C) | 0.03 |
| Silicon (Si) | 0.8 |
| Manganese (Mn) | 1.2 |
| Phosphorus (P) | 0.035 |
| Sulphur (S) | 0.02 |
| Chromium (Cr) | 24.0/26.0 |
| Molybdenum (Mo) | 3.0/3.5 |
| Nickel (Ni) | 6.00/8.00 |
| Nitrogen (N) | 0.24/0.32 |
| Other | Cu: 0.50 |
Mechanical Properties of S32750
| DESCRIPTION | DUPLEX 2205 |
|---|---|
| Proof Stress 0.2% (MPa) | 450 |
| Tensile strength (MPa) | 620 |
| Elongation A5 (%) | 20 |
| Hardness | HB: 293 HRB: 96 (according to Rockwell C Scale) |
Physical properties of 2507 duplex stainless steel plate
| Density | lb/in3 | 0.28 |
|---|---|---|
| Modulus of Elasticity | psi x 106 | 29 |
| Coefficient of Thermal Expansion 68-212°F/°F | x10-6/°F | 7.2 |
| Thermal Conductivity | Btu/h ft °F | 8.7 |
| Heat Capacity | Btu/lb/°F | 0.12 |
| Electrical Resistivity | W-in x 10-6 | 31.5 |
Equivalent Standards of 2507 Duplex Stainless Steel:
ASTM/ASME ………. A240 – UNS S32750
EURONORM………… 1.4410 – X2 Cr Ni MoN 25.7.4
AFNOR……………….. Z3 CN 25.06 Az