S32760 1.4501 Super Duplex Pipe With Excellent Pitting And Stress Corrosion Cracking Resistance

S32760 (1.4501) Super Duplex Pipe With Excellent Pitting and Stress Corrosion Cracking Resistance

Products Specification

verview of S32760 Duplex Stainless Steel Pipe

Microstructural Design and Alloy Chemistry

• Chromium (25%): Forms a passive oxide layer for corrosion resistance.
• Nickel (7%): Enhances ductility and resistance to reducing acids.
• Molybdenum (4.5%) & Tungsten (1%): Synergistically combat pitting in chloride solutions.
• Nitrogen (0.25%): Boosts strength and suppresses intergranular corrosion.
  This design gives S32760 a PREN (Pitting Resistance Equivalent Number) exceeding 40, far surpassing standard stainless steels.

Mechanical Performance Under Stress

• Yield Strength: 550–650 MPa (80–94 ksi), ideal for high-pressure systems.
• Impact Toughness: ≥100 J at -40°C, ensuring reliability in cryogenic or offshore conditions.
• Creep Resistance: Maintains structural integrity at temperatures up to 350°C, outperforming 2205 duplex in high-heat applications.
  Its dual-phase structure minimizes ductile-brittle transition, critical for fatigue-prone installations.

Corrosion Resistance Mechanisms

• Chloride Environments: Resists pitting in seawater (up to 3.5% salinity) and brine systems, making it suitable for subsea pipelines.
• Sour Gas Service: Withstands H₂S and CO₂ in oil wells (up to 100,000 ppm Cl⁻), meeting NACE MR0175 standards.
• Acid Resistance: Tolerates sulfuric and phosphoric acids at moderate concentrations, critical in fertilizer production.
• Galvanic Compatibility: Low electrode potential reduces corrosion when mated with carbon steel in cathodic protection systems.

Industry-Specific Applications

1. Offshore Oil & Gas:
   • Subsea flowlines and risers in deepwater fields (e.g., Gulf of Mexico, North Sea).
   • Chemical injection lines for corrosion inhibitor delivery.
2. Marine Desalination:
   • Heat exchangers in reverse osmosis plants handling seawater at high temperatures.
3. Pharmaceutical Manufacturing:
   • Reactors for high-purity processes involving chlorinated solvents or acids.
4. Wastewater Treatment:
   • Sludge processing equipment exposed to chloride and sulfur compounds.

Fabrication and Installation Advantages

• Welding Flexibility: Gas Tungsten Arc Welding (GTAW) or Shielded Metal Arc Welding (SMAW) with ER2594 filler metal.
• Formability: Can be cold-worked for pipe bends or flanges, though annealing may be needed post-deformation.
• Non-Magnetic Properties: Suitable for applications near magnetic fields (e.g., subsea sensors).
• Cost-Effectiveness: While pricier than 316L, its longevity reduces lifecycle costs by 30–50% in harsh environments.

Standards and Quality Control

• Material Certifications: Complies with ASTM A815, API 5L (PSL2), and EN 10216-5.
• Testing Protocols: Mandatory autogenous weld tests (ASTM G48) and ultrasonic inspection for wall thickness uniformity.
• Traceability: Heat number marking ensures full material traceability from mill to installation.

Technical Comparisons

Environmental Considerations

• Recyclability: 100% recyclable, with scrap value ~2.5x carbon steel.
• Low Emission Fabrication: Welding processes produce minimal hazardous fumes compared to high-nickel alloys.
• Long-Term Sustainability: Reduces replacement needs in coastal infrastructure, minimizing environmental disruption.

1.4501 Duplex Pipe

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S32760 1.4501 Super Duplex Pipe With Excellent Pitting And Stress Corrosion Cracking Resistance Images