UNS S32750 1.4410 S32507 3022Cr25Ni7Mo4N SUPER DUPLEX STEEL SEAMLESS PIPE AND TUBE

Product Introduction

Engineered as a premium alloy, the Super Duplex Stainless Steel S32750 seamless pipe combines the best of austenitic and ferritic stainless steels, featuring a unique duplex microstructure that delivers unparalleled strength and corrosion resistance. With a tensile strength exceeding 116 ksi (800 MPa) and yield strength of 80 ksi (550 MPa), this material outperforms conventional stainless steels in harsh conditions. The high concentration of chromium (24-26%), molybdenum (3-5%), and nitrogen (0.24-0.32%) forms a robust passive layer, ensuring exceptional resistance to chloride-induced stress corrosion, pitting, and crevice corrosion. Manufactured via seamless extrusion, the pipes exhibit uniform grain structure and pressure tolerance, making them ideal for high-stress, high-corrosion applications across industries.

Key Product Parameters

1. Standards Compliance

• ASTM A789: Seamless/Welded Ferritic-Austenitic Stainless Steel Tubing

• ASTM A790: Seamless/Welded Austenitic Stainless Steel Pipes

• ASME SA789/SA790, EN 10216-5, and ISO 1127 standards

2. Dimension Range

• Outer Diameter: 6 mm to 720 mm (0.24" to 28.3")

• Wall Thickness: 1 mm to 65 mm (0.04" to 2.56")

• Length: Customizable up to 12 meters (standard: 6 meters)

3. Chemical Composition (wt.%)

   Element	C	Mn	P	S	Si	Ni	Cr	Mo	N	Cu
   S32750	≤0.03	≤1.20	≤0.035	≤0.02	≤0.80	6.0-8.0	24.0-26.0	3.0-5.0	0.24-0.32	≤0.5
   PREN Calculation: Cr + 3.3Mo + 16N ≥ 41

4. Mechanical Properties

   Property	Value
   Tensile Strength	≥116 ksi (800 MPa)
   Yield Strength	≥80 ksi (550 MPa)
   Elongation at Break	≥15%
   Hardness (HBW)	≤300
   Impact Toughness (at 20°C)	≥40 J/cm²

5. Manufacturing & Surface Treatment

• Process: Hot-rolled, cold-drawn, or extruded seamless

• Surface: Pickled & annealed (standard), polished (Ra ≤0.8μm), bright annealed

• Certification: Mill test certificates, 3.2 EN 10204, NACE MR0175 compliance (optional)

  
  

Application Scenarios

1. Offshore Oil & Gas Exploration

• Critical for subsea pipelines, risers, and wellhead equipment, resisting H₂S and CO₂ corrosion in deepwater environments. Its high strength reduces wall thickness requirements, minimizing weight for offshore installations.

2. Chemical Process Industries

• Used in reactor vessels, distillation columns, and heat exchangers handling sulfuric acid, hydrochloric acid, or brine solutions. The alloy’s resistance to intergranular corrosion ensures long-term reliability in chemical processing.

3. Marine & Desalination Plants

• Ideal for seawater intake systems, condenser tubes, and desalination equipment, withstanding saltwater erosion and biofouling. Its PREN value exceeds 41, making it highly resistant to pitting in chloride-rich environments.

4. Power Generation

• Applied in coastal power plants for seawater cooling systems, flue gas desulfurization (FGD) equipment, and waste heat boilers. The material’s corrosion-fatigue resistance extends service life in cyclic stress conditions.

5. Pharmaceutical & Food Processing

• Meets hygienic standards for pipelines and tanks in pharmaceutical manufacturing and food processing, offering easy cleanability and resistance to caustic cleaning agents.

6. Chemical Tanker & Pipeline Infrastructure

• Used in cargo tanks and transfer systems for transporting aggressive chemicals, ensuring compliance with IMO regulations for hazardous material handling.

FAQ (Frequently Asked Questions)

1. Q: How does Super Duplex S32750 differ from lean duplex stainless steels?
   A: Unlike lean duplex grades (e.g., S32304), S32750 features higher nickel, molybdenum, and nitrogen content, delivering superior corrosion resistance (PREN ≥41 vs. ≤32) and mechanical strength, making it suitable for more aggressive environments.

2. Q: Can S32750 be used in subzero temperatures?
   A: Yes, the alloy maintains ductility and impact resistance down to -50°C, making it suitable for cryogenic applications like LNG processing and Arctic oil fields.

3. Q: What is the recommended welding procedure for S32750?
   A: Use low-heat-input techniques (e.g., TIG welding) with interpass temperatures ≤250°C. Fillers should match the base metal (e.g., ER2553) to maintain duplex phase balance. Post-weld heat treatment is rarely needed if parameters are controlled.

4. Q: How does S32750 perform in high-temperature applications?
   A: Service temperatures up to 300°C are recommended. Prolonged exposure above 350°C may cause sigma phase precipitation, reducing corrosion resistance. For higher temperatures, consider specialty alloys like Inconel.

5. Q: Is S32750 compliant with NACE standards for sour gas service?
   A: Yes, when properly heat-treated, S32750 meets NACE MR0175 requirements for H₂S-containing environments, making it suitable for sour oil and gas applications.

6. Q: What is the typical lead time for custom-sized orders?
   A: Standard sizes are available within 2-4 weeks, while custom dimensions (e.g., non-standard OD/Thickness) require 6-8 weeks for manufacturing, excluding testing and certification processes.

7. Q: How to verify the authenticity of S32750 material?
   A: Each batch is traceable via heat numbers marked on the pipe, cross-referenced with mill test certificates detailing chemical composition and mechanical properties. Third-party PMI (positive material identification) testing is also available.

With its unique balance of strength, corrosion resistance, and weldability, Super Duplex Stainless Steel S32750 seamless pipe sets the standard for critical infrastructure in industries where failure is not an option. Contact our technical team for application-specific solutions and material compatibility assessments.