Product Description
Super Duplex 2507 is the premier grade in the duplex stainless steel family, offering yield strength approximately double that of 316L stainless steel (550 MPa vs 220 MPa) while delivering corrosion resistance comparable to nickel alloys at a fraction of the cost . With high chromium (24-26%), molybdenum (3-5%), and nitrogen (0.24-0.32%) content, Super Duplex 2507 achieves PREN ≥ 40, ensuring reliable performance in the most demanding seawater and chloride environments. The alloy is also available as UNS S32760 (F55) with copper and tungsten additions for enhanced corrosion resistance.
Key characteristics include:
Exceptional corrosion resistance – PREN ≥ 40
Highest strength among duplex stainless steels
Superior chloride stress corrosion cracking resistance
Excellent pitting and crevice corrosion resistance in seawater
Good weldability with proper procedures and filler metals
Cost-effective alternative to nickel alloys
Wide operating temperature range from -50°C to 300°C
Chemical Composition
| Element | UNS S32750 (F53) | UNS S32760 (F55) | Role |
| Chromium (Cr) | 24.0 – 26.0 | 24.0 – 26.0 | Oxidation resistance, corrosion resistance |
| Nickel (Ni) | 6.0 – 8.0 | 6.0 – 8.0 | Austenite stabilizer, corrosion resistance |
| Molybdenum (Mo) | 3.0 – 5.0 | 3.0 – 4.0 | Pitting and crevice corrosion resistance |
| Nitrogen (N) | 0.24 – 0.32 | 0.20 – 0.30 | Austenite stabilizer, strengthening |
| Carbon (C) | ≤ 0.030 | ≤ 0.030 | Controlled for weldability |
| Manganese (Mn) | ≤ 1.20 | ≤ 1.00 | Deoxidizer |
| Silicon (Si) | ≤ 0.80 | ≤ 1.00 | Deoxidizer |
| Copper (Cu) | ≤ 0.50 | 0.50 – 1.00 | Enhances resistance to reducing acids |
| Tungsten (W) | – | 0.50 – 1.00 | Enhanced pitting resistance |
| Phosphorus (P) | ≤ 0.030 | ≤ 0.030 | Impurity control |
| Sulfur (S) | ≤ 0.020 | ≤ 0.010 | Impurity control |
| Iron (Fe) | Balance | Balance | Base element |
Room Temperature Properties (Solution Annealed)
| Property | UNS S32750 (F53) |
| Tensile Strength | ≥ 800 MPa (116 ksi) |
| Yield Strength (0.2% Offset) | ≥ 550 MPa (80 ksi) |
| Elongation | ≥ 25% |
| Hardness | ≤ 290 HB |
| Density | 7.80 g/cm³ |
| PREN (F53) | ≥ 40 |
| Critical Pitting Temperature (CPT) | ≥ 80°C |
Impact Properties (Typical)
| Temperature | Impact Energy (Longitudinal) |
| Room Temperature | ≥ 100 J |
| -40°C | ≥ 50 J |
| -50°C | ≥ 27 J |
Key Advantages of Super Duplex 2507
Exceptional Corrosion Resistance – Super Duplex 2507 offers the highest corrosion resistance among duplex stainless steels. With PREN ≥ 40, the alloy provides exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking in the most aggressive chloride environments including seawater, brine, and acidic chloride solutions.
Highest Strength Among Duplex Steels – Super Duplex 2507 provides the highest strength of any duplex stainless steel grade, with minimum yield strength of 550 MPa. This allows designers to specify significantly thinner wall sections, reducing weight and material costs in critical applications.
Superior Chloride Stress Corrosion Cracking Resistance – The ferritic-austenitic microstructure provides outstanding resistance to chloride stress corrosion cracking (SCC), making Super Duplex 2507 suitable for the most demanding offshore and marine environments where SCC is a critical concern.
Excellent Seawater Performance – Super Duplex 2507 is one of the few materials suitable for long-term seawater service without corrosion. Its PREN ≥ 40 ensures resistance to pitting and crevice corrosion in seawater, making it the material of choice for subsea equipment and offshore platform systems.
Good Weldability – Super Duplex 2507 can be welded using standard techniques (GTAW, GMAW, SMAW, SAW) with appropriate filler metals (typically ER2594 or ER2507). Proper heat input control and interpass temperature management are essential to maintain the correct ferrite-austenite balance and corrosion resistance in the weld zone.
NACE MR0175 / ISO 15156 Compliance – Super Duplex 2507 is qualified for sour service applications in the oil and gas industry, resisting sulfide stress cracking (SSC) and hydrogen induced cracking (HIC) in H₂S-containing environments.
Cost-Effective Alternative – Super Duplex 2507 provides corrosion resistance comparable to nickel alloys such as Inconel 625 at a significantly lower cost, making it an attractive alternative for demanding applications.
NORSOK M-630 Compliance – The alloy meets the requirements of NORSOK M-630 for offshore applications, making it suitable for use on Norwegian continental shelf projects.
Super Duplex 2507 vs Duplex 2205
| Property | Super Duplex 2507 (F53) | Duplex 2205 (F60) |
| PREN | ≥ 40 | ≥ 36 |
| Yield Strength | ≥ 550 MPa | ≥ 450 MPa |
| Cr Content | 24-26% | 22-23% |
| Mo Content | 3-5% | 3.0-3.5% |
| N Content | 0.24-0.32% | 0.14-0.20% |
| CPT (Seawater) | ≥ 80°C | ≥ 50°C |
| Seawater Performance | Superior | Excellent |
| Sour Service | Excellent | Good |
| Cost | Higher | Moderate |
| Application | Extreme seawater, subsea, HPHT | General chemical, marine, oil & gas |
Super Duplex 2507 vs 6Mo Super Austenitic
| Property | Super Duplex 2507 | 6Mo (UNS S31254) |
| PREN | ≥ 40 | ≥ 42 |
| Yield Strength | ≥ 550 MPa | ≥ 310 MPa |
| Cost | Lower | Higher |
| SCC Resistance | Excellent | Very Good |
| Weldability | Good | Excellent |
Available Product Forms from Womic Steel
Seamless Pipe & Seamless Tube
Outside Diameter: 6mm – 300mm (1/4" – 12")
Wall Thickness: 1mm – 30mm
Length: Up to 12m
Standards: ASTM A790, ASTM A789, ASME SA-790
Applications: Seawater piping, subsea flowlines, heat exchanger tubes, hydraulic lines
Keywords: Super Duplex 2507 seamless pipe, UNS S32750 tube, F53 pipe, 1.4410 seamless tube, SAF 2507 pipe
Welded Pipe
Outside Diameter: 50mm – 1200mm (2" – 48")
Wall Thickness: 1.0mm – 25mm
Standards: ASTM A790, ASTM A928, ASME SA-790
Applications: Large-diameter seawater systems, offshore platform piping, desalination plants
Keywords: Super Duplex 2507 welded pipe, F53 ERW pipe, 2507 large diameter pipe
Steel Bar (Round, Square, Flat, Hex)
Diameter: 6mm – 400mm
Surface: Hot rolled, Bright (cold drawn), Ground, Turned, Peeled
Standards: ASTM A276, ASTM A479, ASME SA-479
Applications: Valve stems, fasteners, shafts, pumps, subsea components, machining stock
Keywords: Super Duplex 2507 round bar, F53 bar stock, S32750 bar
Steel Plate & Sheet
Thickness: 1mm – 80mm
Width: Up to 2500mm
Standards: ASTM A240, ASME SA-240
Applications: Vessel shells, subsea structures, flange blanks, pressure vessel plates
Keywords: Super Duplex 2507 plate, F53 sheet, S32750 plate
Steel Coil & Strip
Thickness: 0.5mm – 6.0mm
Width: 10mm – 1500mm
Standards: ASTM A240
Applications: Formed components, bellows, expansion joints
Keywords: Super Duplex 2507 coil, F53 strip
Flanges & Pipe Fittings
Types: Weld Neck, Slip-On, Blind, Socket Weld, Threaded, Lap Joint
Sizes: 1/2" – 48"
Pressure Rating: Class 150 – Class 2500
Standards: ASTM A182, ASME SA-182, ASME B16.5, ASME B16.47
Keywords: Super Duplex 2507 flanges, F53 weld neck flange
Forgings
Types: Rings, disks, shafts, valve bodies, subsea components
Weight: Up to 4,000kg
Standards: ASTM A182, ASME SA-182
Keywords: Super Duplex 2507 forging, F53 ring
Super Duplex 2507 Valves
Types: Ball valves, Gate valves, Globe valves, Check valves
Sizes: 1/2" – 24"
Pressure Rating: Class 150 – Class 2500
Temperature Range: -50°C to +300°C
Design Standards: API 608, API 6D, ASME B16.34
Seating: Stellite hardfaced, RPTFE, PEEK
Keywords: Super Duplex 2507 ball valve, F53 gate valve
Applications of Super Duplex 2507
Offshore Platforms and Subsea Equipment – Super Duplex 2507 is the material of choice for subsea equipment including manifolds, trees, connectors, and flowline systems in deepwater offshore developments. Its resistance to seawater corrosion and high strength make it ideal for the most demanding subsea applications.
Seawater Systems – The alloy is widely used in seawater firewater systems, deluge systems, ballast systems, and cooling water systems on offshore platforms and FPSOs where corrosion resistance at high seawater temperatures is critical.
Desalination Plants – Super Duplex 2507 is used in high-pressure seawater piping, brine handling equipment, and evaporator tubes in desalination plants where high salinity and temperature require exceptional corrosion resistance.
Oil and Gas Processing – The alloy is used in HPHT (high pressure high temperature) wellhead equipment, subsea Christmas trees, and process piping in sour service environments. Its NACE MR0175 / ISO 15156 compliance ensures reliable performance in H₂S-containing environments.
Chemical Processing – Super Duplex 2507 is used in equipment handling highly corrosive chemicals including organic acids and chloride-containing process streams.
Heat Exchangers – The alloy is used in seawater heat exchangers, condensers, and coolers where high corrosion resistance and thermal conductivity are required.
Standards & Specifications
| Product Form | ASTM Standard | ASME Standard |
| Seamless Pipe/Tube | ASTM A790, ASTM A789 | ASME SA-790 |
| Welded Pipe | ASTM A790, ASTM A928 | ASME SA-790 |
| Bar/Rod | ASTM A276, ASTM A479 | ASME SA-479 |
| Plate/Sheet/Strip | ASTM A240 | ASME SA-240 |
| Forgings | ASTM A182 | ASME SA-182 |
| UNS Designation | S32750 (F53) | |
| UNS Designation (Enhanced) | S32760 (F55) | |
| W.Nr. | 1.4410 | |
| EN | 1.4410 | |
| NORSOK | M-630 |
Frequently Asked Questions
Q: What is the difference between Super Duplex 2507 (F53) and Duplex 2205 (F60)?
A: Super Duplex 2507 has higher chromium (24-26% vs 22-23%), molybdenum (3-5% vs 3.0-3.5%), and nitrogen (0.24-0.32% vs 0.14-0.20%), providing superior corrosion resistance (PREN ≥ 40 vs ≥ 36) and higher strength (550 MPa vs 450 MPa). It is specifically designed for the most aggressive seawater and chloride environments.
Q: Is Super Duplex 2507 suitable for seawater service?
A: Yes. With PREN ≥ 40, Super Duplex 2507 is one of the few materials suitable for long-term seawater service without corrosion. It is widely used in subsea equipment, offshore platform seawater systems, and desalination plants.
Q: Can Super Duplex 2507 be welded?
A: Yes. Super Duplex 2507 is weldable using GTAW, GMAW, SMAW, and SAW processes. Filler metal ER2594 or ER2507 is recommended. Control of heat input and interpass temperature is critical to maintain proper ferrite-austenite balance and corrosion resistance.
Q: What is the difference between UNS S32750 (F53) and UNS S32760 (F55)?
A: UNS S32760 (F55) contains copper (0.50-1.00%) and tungsten (0.50-1.00%) additions, providing enhanced resistance to reducing acids and slightly improved pitting resistance. It is often specified for more demanding applications.
Q: What is the maximum service temperature for Super Duplex 2507?
A: The recommended maximum service temperature is 300°C (572°F). Above this temperature, the alloy is susceptible to embrittlement due to sigma phase precipitation. The minimum service temperature is approximately -50°C.
Contact Womic Steel
Website: www.womicsteel.com
E-mail: sales@womicsteel.com
Tel / WhatsApp / WeChat:
Victor: +86 15575100681
Jack: +86 18390957568
Womic Steel – Your reliable partner for Super Duplex 2507 (UNS S32750 / F53) seamless pipe, welded pipe, steel bar, steel plate, steel coil, flanges, fittings, forgings, and valves for offshore platforms, subsea equipment, seawater systems, desalination plants, and extreme corrosion applications worldwide. Full traceability, NACE MR0175 compliance, NORSOK M-630, and EN 10204 Type 3.1/3.2 documentation available.
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