Super duplex microstructure with 25% chromium, 4% molybdenum, and nitrogen for exceptional pitting and crevice corrosion resistance (PRE > 41) .
Yield strength approximately twice that of standard austenitic stainless steels, enabling significant weight savings in structural applications .
Excellent resistance to chloride-induced stress corrosion cracking (SCC) in aggressive chloride-bearing environments .
Low coefficient of thermal expansion and high thermal conductivity compared to austenitic stainless steels
Duplex 2507 (UNS S32750) is a super duplex stainless steel designed for applications requiring exceptional strength and superior corrosion resistance. It combines the advantages of both austenitic and ferritic stainless steels, offering excellent performance in harsh environments.
Duplex 2507 plate is widely used in industries such as oil and gas, marine engineering, and chemical processing where resistance to chloride stress corrosion cracking is critical.
Learn more about Duplex 2205 VS 2507
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Specifications & Designations
| Standard | Designation |
|---|---|
| UNS | S32750 |
| W.n.r(Germany) | 1.4410 |
| EN/DIN | X2CrNiMoN 25-7-4 |
| ASTM | A182 (F53), A240, A276, A479 |
| Other Designations | SAF 2507, Alloy 32750, 2507, F53 |
Chemical Composition
| Element | Content (%) | Source |
|---|---|---|
| Chromium (Cr) | 24.0 – 26.0 | |
| Nickel (Ni) | 6.0 – 8.0 | |
| Molybdenum (Mo) | 3.0 – 5.0 | |
| Nitrogen (N) | 0.24 – 0.35 | |
| Carbon (C) | 0.030 max | |
| Manganese (Mn) | 1.20 max | |
| Silicon (Si) | 0.80 max | |
| Copper (Cu) | 0.50 max | |
| Phosphorus (P) | 0.035 max | |
| Sulfur (S) | 0.020 max | |
| Iron (Fe) | Balance |
Mechanical Properties (Annealed)
| Property | Typical Value | |
|---|---|---|
| Tensile Strength | 750 – 930 MPa (109 – 135 ksi) | |
| Yield Strength (0.2% Offset) | 530 – 550 MPa (77 – 80 ksi) min | |
| Elongation | 25 – 30% | |
| Hardness | < 270 HB / < 28 HRC | |
| Impact Strength (Charpy V) | 80 J (room temp) | |
| Impact Strength (-46°C) | 45 J min |
Available Forms & Specifications
| Product Form | Size Range | Typical Specifications |
|---|---|---|
| Bar & Rod | Up to 300mm diameter | ASTM A276, A479, A182 F53 |
| Plate & Sheet | 0.5mm – 100mm thickness | ASTM A240 |
| Strip & Foil | 0.1mm – 5mm thickness | ASTM A240 |
| Pipe & Tube (Seamless) | Custom sizes | ASTM A789, A790 |
| Fittings | Custom configurations | ASTM A815 |
| Wire | 0.025mm – 21mm diameter | ASTM A276 |
| Forgings | Custom configurations | ASTM A182 F53 |
Applications by Industry
| Industry | Applications | |
|---|---|---|
| Oil & Gas | Downhole tubing, casing, wellhead equipment, subsea components, sour gas service | |
| Offshore & Marine | Offshore platforms, seawater piping, propellers, shafts, marine hardware | |
| Chemical Processing | Pressure vessels, reactors, heat exchangers, piping systems | |
| Desalination | Desalination plants, evaporators, brine heaters | |
| Pulp & Paper | Digesters, bleach plants, liquor heaters | |
| Pollution Control | Flue gas desulfurization (FGD), scrubber systems | |
| Food Processing | Food handling equipment, processing vessels | |
| Power Generation | High-stress components in thermal and nuclear plants |
Frequently Asked Questions
Q: What is the difference between Duplex 2205 and Super Duplex 2507?
A: Duplex 2507 has higher chromium (25% vs 22%), molybdenum (4% vs 3%), and nitrogen content, resulting in superior corrosion resistance (PRE > 41 vs > 30) and higher yield strength (550 MPa vs 450 MPa) .
Q: What is the difference between UNS S31803 and UNS S32750?
A: S32750 (Duplex 2507) is a super duplex grade with higher alloy content, providing significantly better pitting resistance and higher strength compared to standard duplex grades like S31803/S32205 .
Q: What is the maximum operating temperature for Duplex 2507?
A: The recommended service temperature range is -50°C to +300°C (-58°F to +572°F). Above 300°C, embrittling phases such as sigma phase can form, reducing toughness and corrosion resistance .
Q: Is Duplex 2507 magnetic?
A: Yes, Duplex 2507 is ferromagnetic due to its ferrite phase content (approximately 35-55% ferrite) .
Q: Can Duplex 2507 be welded without post-weld heat treatment?
A: Yes, Duplex 2507 can be used in the as-welded condition provided proper welding procedures are followed to maintain the ferrite-austenite balance. No post-weld heat treatment is typically required
