Super Duplex Steel UNS S32750 Flanges

What are Super Duplex Steel UNS S32750 Flanges?

Super Duplex Steel UNS S32750 flanges are high-performance piping components used to:

• Connect piping systems: Provide strong, leak-proof joints between pipes and equipment
• Handle extreme pressure and temperature: Ideal for critical industrial applications
• Resist aggressive corrosion: Suitable for highly corrosive and chloride-rich environments
• Ensure system reliability: Deliver long-lasting and dependable performance

These flanges are made from super duplex stainless steel, featuring a balanced austenitic-ferritic structure with enhanced alloy content for superior strength and corrosion resistance.

Composition Highlights (Typical)

Super Duplex Steel UNS S32750:

• Chromium (Cr): 24 – 26% → Excellent corrosion resistance
• Nickel (Ni): 6 – 8% → Enhances toughness
• Molybdenum (Mo): 3 – 5% → Improves pitting resistance
• Nitrogen (N): 0.24 – 0.32% → Increases strength and corrosion resistance
• Carbon (C): ≤ 0.03%
• Iron (Fe): Balance

Key Advantage: High PREN (Pitting Resistance Equivalent Number) ensures exceptional resistance to pitting and crevice corrosion.

Key Features of Super Duplex Steel UNS S32750 Flanges

• Ultra-high strength: Nearly twice the strength of duplex stainless steel
• Exceptional corrosion resistance: Ideal for extreme environments
• Superior resistance to pitting and crevice corrosion
• Outstanding resistance to chloride stress corrosion cracking
• High fatigue strength: Suitable for cyclic loading conditions
• Excellent durability: Performs in harsh marine and chemical environments
• Long service life: Reduced maintenance and replacement costs

Mechanical Properties

Super Duplex Steel S32750:

• Tensile Strength: ~800 – 1000 MPa → Very high load-bearing capacity
• Yield Strength: ≥ 550 MPa → Excellent resistance to deformation
• Elongation: ≥ 15 – 25% → Good ductility

These properties make S32750 ideal for high-pressure and structural applications.

Physical Properties

• Density: ~7.8 g/cm³ → Strong yet relatively lightweight
• Melting Range: 1350 – 1450°C → Suitable for elevated temperatures
• Modulus of Elasticity: ~200 GPa → High stiffness
• Thermal Conductivity: ~14 W/m•K → Moderate heat transfer
• Coefficient of Expansion: ~13 µm/m°C → Low thermal expansion

Corrosion Resistance

Super Duplex Steel S32750 flanges offer exceptional resistance to:

• Seawater and marine environments
• Pitting and crevice corrosion: Very high resistance due to high PREN
• Chloride stress corrosion cracking
• Acidic and chemical environments
• Oxidizing and reducing conditions

This makes them ideal for the most aggressive service conditions.

Heat Treatment

• Solution Annealing: 1020 – 1100°C
• Rapid cooling (water quenching)

This ensures proper phase balance and maximum corrosion resistance.

Weldability

Super Duplex S32750 flanges can be welded using:

• TIG (GTAW) → High-quality welds
• MIG (GMAW) → Efficient fabrication
• SMAW → Suitable for industrial applications

Recommendations:

• Use controlled heat input
• Use matching filler materials
• Maintain correct phase balance

Machinability

• Moderate machinability due to high strength
• Use carbide tooling
• Maintain controlled cutting speeds
• Apply sufficient coolant to reduce heat

Standards & Specifications

• ASTM A182
• ASME SA182
• ANSI B16.5
• ANSI B16.47
• ASTM A240

These standards ensure global quality compliance.

Available Types of Super Duplex Steel Flanges

• Weld Neck Flanges → High-pressure systems
• Slip-On Flanges → Easy installation
• Blind Flanges → Pipe closure
• Socket Weld Flanges → Small pipelines
• Threaded Flanges → Non-weld systems
• Lap Joint Flanges → Easy maintenance
• Orifice Flanges → Flow measurement

Sizes & Specifications

• Size Range: ½ inch to 48 inches
• Pressure Class: 150#, 300#, 600#, 900#, 1500#, 2500#
• Type: Forged

Surface Finish:

• Pickled → Clean and corrosion-resistant
• Polished → Smooth finish
• Machined → Precision engineered

(Custom sizes available as per requirement)

Applications of Super Duplex Steel UNS S32750 Flanges

• Oil & Gas Industry: Used in offshore platforms, subsea pipelines, and high-pressure systems.
• Marine Industry: Ideal for seawater handling and shipbuilding applications.
• Chemical Processing: Handles aggressive chemicals and acids.
• Desalination Plants: Used in high-salinity water systems.
• Power Generation: Applied in heat exchangers and cooling systems.

Quality Testing & Inspection

All flanges undergo strict quality checks:

• Chemical composition testing → Ensures correct material grade
• Mechanical testing → Verifies strength
• Dimensional inspection → Confirms accuracy
• Surface testing → Detects defects
• PMI testing → Confirms material identity

Mill Test Certificates (MTC) and third-party inspection reports are provided.

Packaging & Delivery

• Export-quality wooden packaging
• Protective wrapping
• Proper labeling and traceability
• Safe and timely global shipping

Why Choose Virami Steel Hub?

• Leading super duplex flange manufacturer in Mumbai
• Large stock availability
• Competitive pricing
• Custom manufacturing solutions
• Compliance with international standards
• Strong export network
• Dedicated customer support

Conclusion

Super Duplex Steel UNS S32750 Flanges are designed for extreme service conditions where high strength and superior corrosion resistance are essential. Their outstanding mechanical properties and resistance to aggressive environments make them ideal for industries such as oil & gas, marine, chemical processing, and desalination.

Virami Steel Hub delivers premium-quality Super Duplex S32750 flanges that meet global standards, ensuring reliability, durability, and long-term performance.