Super Duplex Stainless Steel 2507 (UNS S32750), 255 (UNS S32550)
Super Duplex Stainless Steel 2507 (UNS S32750) and 255 (UNS S32550) are super duplex grades known for their exceptional strength, corrosion resistance, and durability, even in the most demanding environments. These materials combine the benefits of both austenitic and ferritic stainless steels, delivering superior performance, particularly in applications where resistance to extreme corrosion and high mechanical strength are essential. Industries such as oil and gas, chemical processing, and marine engineering rely heavily on these super duplex grades.
Key Features of Super Duplex Stainless Steel 2507 and 255
- High Strength and Toughness: Both 2507 and 255 offer nearly twice the strength of standard austenitic stainless steels, providing high resistance to stress and wear in harsh conditions.
- Exceptional Corrosion Resistance: They are highly resistant to chloride stress corrosion cracking, pitting, and crevice corrosion, making them ideal for marine and chemical processing environments.
- Superior Weldability and Formability: Despite their strength, these grades can be welded and formed with proper techniques, allowing them to adapt to complex and customized applications.
- Resistant to Erosion and Fatigue: These grades are particularly resistant to erosion and fatigue in dynamic environments, such as seawater and processing plants with abrasive fluids.
- Cost-Effectiveness: The high strength and durability of these alloys allow for thinner material usage in structures, offering significant cost savings in both material and fabrication.
Chemical Composition
- Super Duplex 2507 (UNS S32750):
- Chromium (Cr): 24-26%
- Nickel (Ni): 6-8%
- Molybdenum (Mo): 3-5%
- Nitrogen (N): 0.24-0.32%
- Iron (Fe): Balance
- Super Duplex 255 (UNS S32550):
- Chromium (Cr): 24-27%
- Nickel (Ni): 4.5-6.5%
- Molybdenum (Mo): 2.9-3.9%
- Copper (Cu): 1.5-2.5%
- Nitrogen (N): 0.1-0.25%
- Iron (Fe): Balance
These compositions create a high chromium and molybdenum content that provides excellent corrosion resistance, while the addition of nitrogen increases strength and pitting resistance.
Mechanical Properties
- Super Duplex 2507:
- Tensile Strength: 795 MPa (minimum)
- Yield Strength: 550 MPa (minimum)
- Elongation: 15%
- Hardness: 32 HRC (maximum)
- Super Duplex 255:
- Tensile Strength: 750 MPa (minimum)
- Yield Strength: 550 MPa (minimum)
- Elongation: 20%
- Hardness: 28-32 HRC
The high strength and elongation values make these grades suitable for heavy-duty applications where both flexibility and resistance to deformation are needed.
Applications of Super Duplex 2507 and 255
- Oil and Gas Industry: Ideal for offshore platforms, oil rigs, and pipelines due to their resistance to corrosion in chloride-rich seawater and other harsh conditions.
- Chemical Processing: Used in equipment for handling sulfuric acid, phosphoric acid, and other corrosive chemicals due to their high resistance to corrosion.
- Desalination and Water Treatment: Perfect for seawater desalination plants, heat exchangers, and other equipment exposed to seawater.
- Marine Applications: Suited for shipbuilding, propeller shafts, and marine fasteners, where exposure to saltwater is a constant factor.
- Power Generation: Used in nuclear and fossil fuel power plants for components that encounter high temperatures and corrosive environments.
Manufacturing Standards
Super Duplex Stainless Steel 2507 and 255 are manufactured according to international standards to ensure quality, durability, and performance:
- ASTM A240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels.
- ASTM A790: Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe.
- ASTM A182: Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Fittings, Valves, and Parts.
- ASME SA240, SA789, SA790: ASME standards for pressure vessel applications.
Available Forms and Customization Options
- Forms: Available in sheets, plates, bars, rods, pipes, tubes, and fittings.
- Dimensions: Standard and custom sizes available to suit project requirements.
- Surface Finishes: Mill, polished, and customized finishes available for diverse applications.
- Heat Treatments: Solution annealing available to improve mechanical and corrosion-resistant properties.
Quality Assurance and Certifications
Super Duplex 2507 and 255 products undergo rigorous testing to ensure optimal quality and compliance:
- Mechanical Testing: Confirms strength, elongation, and hardness.
- Corrosion Testing: Verifies resistance to pitting, crevice corrosion, and chloride stress corrosion cracking.
- Dimensional Accuracy: Precision cutting and machining ensure compliance with specified tolerances.
FAQs
Products
Industry We Serve
- Oil & Gas industries
- Chemical process industries
- Pump and valve in high pressure component
- Food industries
- Pulp and paper industry
- Aerospace industry
- Power plant
- Mechanical component
- Sugar industry
- Cement industry