Product Description
S32760 (F55) is a premium super duplex stainless steel with exceptional corrosion resistance and outstanding mechanical properties. With a balanced austenitic-ferritic microstructure (approximately 50:50), this advanced alloy contains high levels of chromium (24-26%), nickel (6-8%), molybdenum (3-4%), copper (0.5-1.0%), nitrogen (0.2-0.3%), and tungsten (0.5-1.0%), creating a material with superior resistance to various corrosive environments, particularly in marine and chloride-containing conditions.
The unique chemical composition of S32760 (F55) provides a Pitting Resistance Equivalent Number (PREN) of 40 or higher, significantly enhancing its resistance to localized corrosion compared to standard duplex and austenitic stainless steels. The addition of tungsten further improves the alloy’s corrosion resistance properties, particularly in acidic environments, while the controlled nitrogen content contributes to both strength and corrosion performance.
FUSHUN METAL supplies premium quality S32760 super duplex stainless steel that combines high mechanical strength (typically up to 600 MPa yield strength) with good ductility and outstanding corrosion resistance to marine environments and a wide range of oil and gas production environments. This versatile material offers excellent resistance to pitting corrosion, crevice corrosion, and stress corrosion cracking, making it an ideal solution for challenging applications in the oil and gas industry, chemical processing, marine environments, hydropower, and other demanding sectors.
Applications
S32760 (F55) super duplex stainless steel is engineered for the most challenging environments where its unique combination of superior corrosion resistance and high mechanical strength provides exceptional performance and reliability. Key applications include:
- Oil and Gas Industry: Downhole equipment, wellhead components, Christmas trees, subsea equipment, pumps, valves, chokes, manifolds, pipework, flanges, bolting, connectors, band clamps, and pressure vessels. The excellent resistance to chloride-containing environments and sour service conditions makes S32760 particularly valuable in offshore and subsea applications.
- Marine Applications: Propeller shafts, seawater systems, structural components, fasteners, and equipment exposed to marine environments. The high resistance to seawater corrosion and mechanical strength make S32760 an excellent choice for marine engineering applications.
- Chemical Processing: Pressure vessels, reactors, heat exchangers, storage tanks, piping systems, and processing equipment handling aggressive chemicals. The superior resistance to various corrosive media makes S32760 suitable for processing equipment in chemical plants.
- Pulp and Paper Industry: Bleaching equipment, digesters, and processing machinery exposed to corrosive chloride-containing chemicals in pulp production.
- Hydropower: Components for hydroelectric power generation systems where resistance to erosion corrosion and high mechanical strength are essential.
- Desalination: High-pressure pumps, valves, and piping systems in seawater desalination plants where resistance to chloride pitting and crevice corrosion is critical.
- Defense Industry: Various components requiring high strength combined with excellent corrosion resistance in marine and other aggressive environments.
- Structural Applications: Load-bearing components in aggressive environments where high strength and corrosion resistance are required, such as offshore platforms and bridge components.
The exceptional combination of high strength, excellent corrosion resistance, and good fabricability makes S32760 super duplex stainless steel an economical alternative to more expensive nickel-based alloys and titanium in many applications. It can be used successfully as an alternative to 300 series stainless steel (such as type 316), standard 22% Cr duplex steel, and precipitation hardening stainless steels. Where appropriate, it can even be considered in lieu of more costly Grade 5 titanium or nickel-based alloys.
Standards
S32760 (F55) super duplex stainless steel conforms to numerous international standards and specifications, ensuring consistent quality and performance in demanding applications:
American Standards:
- UNS: S32760
- ASTM A276/A276M: Standard Specification for Stainless Steel Bars and Shapes
- ASTM A479/A479M: Standard Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels
- ASTM A182: Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service (Grade F55)
European Standards:
- EN Number: 1.4501
- EN 10088-3: Stainless steels – Technical delivery conditions for semi-finished products, bars, rods and sections for general use (Grade X2CrNiMoCuWN25-7-4)
International Standards:
- NACE MR0175/ISO 15156: Materials for use in H₂S-containing environments in oil and gas production
- NORSOK M-650: Qualification of manufacturers of special materials
- NORSOK M-630: Material data sheets and element data sheets for piping (MDS-D51 to D55, D57 & D58)
These comprehensive standards ensure that S32760 super duplex stainless steel from FUSHUN METAL meets the rigorous requirements for use in critical applications across various industries, particularly where high strength and exceptional corrosion resistance are essential.
Material Designation and Chemical Composition
S32760 super duplex stainless steel is known by various designations in different standards and specification systems:
| Standard System | Designation |
|---|---|
| UNS | S32760 |
| EN | 1.4501 |
| EN Name | X2CrNiMoCuWN25-7-4 |
| ASTM | F55 |
The chemical composition of S32760 super duplex stainless steel is carefully controlled to ensure optimal performance in demanding environments:
| Element | Minimum (%) | Maximum (%) |
|---|---|---|
| Chromium (Cr) | 24.0 | 26.0 |
| Nickel (Ni) | 6.0 | 8.0 |
| Molybdenum (Mo) | 3.0 | 4.0 |
| Copper (Cu) | 0.5 | 1.0 |
| Tungsten (W) | 0.5 | 1.0 |
| Nitrogen (N) | 0.2 | 0.3 |
| Carbon (C) | – | 0.03 |
| Silicon (Si) | – | 1.0 |
| Manganese (Mn) | – | 1.0 |
| Phosphorus (P) | – | 0.03 |
| Sulfur (S) | – | 0.01 |
| Iron (Fe) | Balance | – |
The high levels of chromium, molybdenum, nitrogen, and tungsten in S32760 result in a Pitting Resistance Equivalent Number (PREN = %Cr + 3.3 × %Mo + 16 × %N) of 40 or higher, providing exceptional resistance to localized corrosion in aggressive environments. The balanced chemical composition also ensures an optimal dual-phase microstructure with approximately equal proportions of austenite and ferrite for superior mechanical properties and corrosion resistance.
Physical and Mechanical Properties
S32760 (F55) super duplex stainless steel offers an exceptional combination of high strength and excellent corrosion resistance, making it ideal for demanding applications where conventional stainless steels would be inadequate.
Mechanical Properties
The mechanical properties of S32760 are significantly superior to those of conventional austenitic stainless steels and standard duplex grades:
| Property | Value |
|---|---|
| Ultimate Tensile Strength (minimum) | 109 ksi (750 MPa) |
| 0.2% Yield Strength (minimum) | 80 ksi (550 MPa) |
| Elongation (minimum) | 25% |
| Reduction of Area (minimum) | 45% |
| Hardness (maximum) | 310 HBW (32 HRC) |
| Impact Energy at -46°C (minimum) | 45 J (33 ft-lbs) |
According to EN 10088-3 for 1.4501 (solution annealed condition, maximum diameter 160mm):
| Property | Value |
|---|---|
| Ultimate Tensile Strength | 730-930 MPa (106-135 ksi) |
| 0.2% Proof Strength (minimum) | 530 MPa (77 ksi) |
| Elongation (minimum) | 25% |
| Hardness (maximum) | 290 HB |
| Impact Energy at 20°C (minimum) | 100 J (74 ft-lbs) |
Physical Properties
| Property | Value |
|---|---|
| Density | 0.285 lb/in³ (7.8 g/cm³) at 68°F (20°C) |
| Melting Range | 2525-2630°F (1385-1443°C) |
| Modulus of Elasticity at 68°F (20°C) | 29 × 10⁶ psi (200 GPa) |
| Thermal Conductivity at 68°F (20°C) | 15 W/m·K |
| Coefficient of Thermal Expansion (68-212°F/20-100°C) | 13.0 × 10⁻⁶ /K |
| Specific Heat at 68°F (20°C) | 500 J/kg·K |
| Electrical Resistivity | 0.80 Ω·mm²/m |
| Magnetic Permeability | <1.05 at 68°F (20°C) |
Corrosion Resistance
S32760 super duplex stainless steel offers exceptional resistance to various forms of corrosion:
- Pitting and Crevice Corrosion: With a PREN value of 40 or higher, S32760 provides excellent resistance to localized corrosion in chloride-containing environments, particularly in marine applications.
- Stress Corrosion Cracking: Superior resistance to chloride stress corrosion cracking compared to conventional austenitic stainless steels and standard duplex grades.
- General Corrosion: Excellent resistance to uniform corrosion in a wide range of aggressive media, including seawater and various chemical environments.
- Erosion Corrosion: High hardness and corrosion resistance provide good protection against erosion-corrosion in flowing media.
- Corrosion Fatigue: Superior resistance to corrosion fatigue compared to conventional stainless steels, making it suitable for cyclically loaded components in corrosive environments.
The corrosion resistance of S32760 is particularly valuable in seawater and other chloride-containing environments, making it an ideal choice for offshore, marine, and chemical processing applications.
Heat Treatment
S32760 super duplex stainless steel is supplied in the solution annealed condition to ensure optimal corrosion resistance and mechanical properties. The recommended heat treatment process involves:
- Solution Annealing Temperature: 1100°C (2012°F)
- Cooling: Water quenching to prevent the formation of deleterious phases
Like other duplex stainless steels, S32760 is susceptible to embrittlement and loss of toughness when exposed to prolonged use in applications or environments below -50°F (-46°C) or above 600°F (315°C). For this reason, S32760 should be limited to applications within this temperature range.
Available Dimensions
FUSHUN METAL offers S32760 (F55) super duplex stainless steel in a comprehensive range of product forms and dimensions to meet diverse application requirements:
Plate and Sheet
| Product Form | Thickness | Width | Length |
|---|---|---|---|
| Plate | 5.0 mm – 150 mm (0.197″ – 5.9″) | Up to 3,000 mm (118″) | Up to 12,000 mm (472″) |
| Sheet | 0.5 mm – 4.9 mm (0.020″ – 0.193″) | Up to 1,500 mm (59″) | Up to 6,000 mm (236″) |
Bar and Rod
| Product Form | Diameter/Dimension | Length |
|---|---|---|
| Round Bar | 10 mm – 400 mm (0.394″ – 15.75″) | Up to 6,000 mm (236″) |
| Square Bar | 10 mm – 200 mm (0.394″ – 7.87″) | Up to 6,000 mm (236″) |
| Flat Bar | Thickness: 5 mm – 100 mm (0.197″ – 3.94″) Width: 10 mm – 300 mm (0.394″ – 11.8″) |
Up to 6,000 mm (236″) |
| Hexagonal Bar | 10 mm – 100 mm (0.394″ – 3.94″) across flats | Up to 6,000 mm (236″) |
Pipe and Tube
| Product Form | Outside Diameter | Wall Thickness | Length |
|---|---|---|---|
| Seamless Pipe | 10 mm – 450 mm (0.394″ – 17.7″) | Schedule 10S – XXS | Up to 12,000 mm (472″) |
| Welded Pipe | 10 mm – 1,200 mm (0.394″ – 47.2″) | Schedule 10S – XXS | Up to 12,000 mm (472″) |
| Seamless Tube | 6 mm – 50.8 mm (0.236″ – 2″) | 0.5 mm – 12.7 mm (0.020″ – 0.500″) | Up to 25,000 mm (984″) |
Forgings and Custom Components
FUSHUN METAL also provides a wide range of forgings and custom-manufactured components in S32760 super duplex stainless steel:
- Closed die forgings
- Open die forgings
- Rings and flanges
- Blocks and discs
- Custom-designed components for specific applications
In addition, we offer S32760 welding consumables to ensure proper welding of components, maintaining the superior corrosion resistance and mechanical properties of the base material.
Custom dimensions and special profiles can be produced to meet specific customer requirements. Please contact our sales team for more information about non-standard sizes and special specifications.
Fabrication Information
S32760 (F55) super duplex stainless steel can be successfully fabricated using conventional methods, but there are some important considerations to ensure optimal performance of the finished components:
Machinability
The machining of S32760 super duplex stainless steel presents no particular problems, although its high strength requires adjustments compared to austenitic stainless steels:
- Use sharper tools and lower cutting speeds compared to austenitic stainless steels
- Ensure rigid tooling setups to minimize vibration
- Provide adequate cooling during machining operations
- Use tools designed specifically for high-strength stainless steels
Welding
S32760 has very good weldability but requires specific procedures to maintain optimal properties:
- Use matching filler metals with similar or slightly higher alloy content
- Control heat input to avoid excessive ferrite formation and precipitation of intermetallic phases
- Maintain interpass temperature below 150°C (302°F)
- Avoid preheating except in cases of extreme cold ambient conditions
- Ensure proper shielding gas coverage to prevent oxidation
- Follow proper procedures to maintain the balanced austenite-ferrite microstructure in the weld and heat-affected zone
Forming
Due to its high strength, forming of S32760 requires more force than austenitic stainless steels:
- Hot forming should be performed at temperatures between 950-1150°C (1742-2102°F)
- Cold forming requires greater force due to the higher strength of the material
- The minimum bend radius for cold forming is typically larger than for austenitic stainless steels
- Solution annealing after significant forming is recommended to restore optimal properties
Heat Treatment
Proper heat treatment is essential to maintain the optimal properties of S32760:
- Solution annealing at 1100°C (2012°F) followed by water quenching is the standard heat treatment
- Avoid prolonged exposure to temperatures between 300-1000°C (572-1832°F) to prevent embrittlement
- For stress relief, only short-term exposure at temperatures below 300°C (572°F) is recommended
- After welding or forming, solution annealing may be necessary to restore optimal properties
S32760 super duplex stainless steel should not be used in applications with continuous service temperatures outside the range of -50°F to +600°F (-46°C to +315°C) due to the risk of embrittlement and loss of toughness.
Why Choose FUSHUN METAL for S32760 (F55) Super Duplex Stainless Steel
When selecting a supplier for premium S32760 (F55) super duplex stainless steel, FUSHUN METAL stands as your preferred partner for several compelling reasons:
Superior Quality Assurance
At FUSHUN METAL, we implement rigorous quality control processes throughout our production chain. Our S32760 super duplex stainless steel undergoes comprehensive testing including chemical analysis, mechanical testing, metallographic examination, and corrosion testing to ensure full compliance with international standards and specifications. Every product is tested according to ASTM G48A for corrosion resistance, guaranteeing that our materials consistently deliver the exceptional performance required in the most demanding applications.
Metallurgical Expertise
Our team of metallurgical specialists possesses extensive experience and knowledge in the production and processing of super duplex stainless steels. This expertise enables us to provide valuable technical support to help you select the optimal material specifications for your specific application requirements. We can assist with material selection, fabrication recommendations, corrosion resistance evaluations, and problem-solving to ensure the success of your projects.
Comprehensive Product Range
FUSHUN METAL offers one of the most extensive ranges of S32760 super duplex stainless steel products available, including plate, sheet, bar, pipe, tube, forgings, flanges, and custom components. This diverse product portfolio allows you to source all your super duplex stainless steel requirements from a single, reliable supplier, streamlining your procurement process and ensuring consistency across your projects.
Specialized Applications Knowledge
With years of experience serving critical industries such as oil and gas, marine, chemical processing, and hydropower, our team understands the specific challenges and requirements of these demanding applications. This specialized knowledge enables us to recommend the most appropriate material specifications and processing parameters to ensure optimal performance in your specific operating environment, whether it’s sour service conditions in oil and gas production, aggressive marine environments, or challenging chemical processing conditions.
Value-Added Services
Beyond supplying premium materials, we offer a range of value-added services including custom cutting, machining, heat treatment, surface finishing, and non-standard dimensions to meet your specific requirements. Our ability to provide tailored solutions helps you optimize your manufacturing processes and reduce overall costs.
For your next project requiring the exceptional corrosion resistance and high strength of S32760 super duplex stainless steel, we invite you to contact our technical team to discuss your specific requirements. Our experts are ready to help you select the optimal material specifications and provide the premium quality products you need for reliable, long-term performance in even the most challenging environments.
