Duplex Stainless Steel 2507 丨S32750

Duplex Stainless Steel 2507丨UNS S32750

Duplex Stainless Steel 2507 (UNS S32750, EN 1.4410) is a super duplex stainless steel engineered for highly aggressive environments containing chlorides, acids, and seawater. The alloy’s balanced ferritic-austenitic microstructure provides exceptional corrosion resistance combined with very high mechanical strength.

With a high chromium, molybdenum, and nitrogen content, 2507 achieves a Pitting Resistance Equivalent Number (PREN) above 40, making it one of the most corrosion-resistant stainless steels available for industrial service.

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2507 At a Glance

Key Attribute	Value
Material	Duplex Stainless Steel 2507
UNS Number	S32750
EN/W.Nr.	1.4410
Material Type	Super Duplex Stainless Steel
Microstructure	50% Austenite / 50% Ferrite
Density	7.8 g/cm³
PREN	> 40
Yield Strength	≥ 550 MPa
Main Advantage	Superior Chloride Corrosion Resistance
Typical Industries	Offshore, Chemical, Marine, Desalination

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Features of 2507

• Exceptional resistance to pitting corrosion
• Excellent crevice corrosion resistance
• Outstanding chloride stress corrosion cracking resistance
• Superior seawater corrosion resistance
• Nearly double the yield strength of 316L stainless steel
• Excellent erosion-corrosion resistance
• High fatigue strength
• Good weldability
• Excellent resistance to sour gas environments
• Cost-effective alternative to nickel alloys in many applications

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Chemical Composition of 2507

Element	Content (%)
Chromium (Cr)	24.0 – 26.0
Nickel (Ni)	6.0 – 8.0
Molybdenum (Mo)	3.0 – 5.0
Nitrogen (N)	0.24 – 0.32
Manganese (Mn)	≤ 1.20
Silicon (Si)	≤ 0.80
Carbon (C)	≤ 0.03
Phosphorus (P)	≤ 0.035
Sulfur (S)	≤ 0.020
Iron (Fe)	Balance

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Physical Properties of 2507

Property	Value
Density	7.8 g/cm³
Melting Range	1350 – 1400°C
Electrical Resistivity	0.80 μΩ·m
Thermal Conductivity	14.0 W/m·K
Specific Heat Capacity	480 J/kg·K
Modulus of Elasticity	200 GPa

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Mechanical Properties of 2507

Annealed Condition

Property	Metric Value
Tensile Strength	≥ 800 MPa
Yield Strength (0.2%)	≥ 550 MPa
Elongation	≥ 15%
Hardness	≤ 310 HB

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Corrosion Resistance

Duplex Stainless Steel 2507 provides outstanding resistance to localized corrosion mechanisms, particularly in chloride-rich environments.

Excellent Resistance To

• Seawater corrosion
• Pitting corrosion
• Crevice corrosion
• Chloride SCC
• Sulfur-containing environments
• Organic acids
• Sour gas service

Typical PREN exceeds 40, significantly outperforming Duplex 2205 and conventional austenitic stainless steels.

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High Temperature Performance

Although primarily selected for corrosion resistance, 2507 also provides good elevated-temperature strength.

Recommended Service Range

• Cryogenic temperatures
• Ambient temperature service
• Continuous operation up to approximately 300°C

For prolonged service above 300°C, phase balance and toughness may be affected.

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Available Forms

J&A Alloy supplies Duplex Stainless Steel 2507 in:

• Round Bar
• Flat Bar
• Forged Bar
• Plate
• Sheet
• Coil
• Pipe
• Tube
• Flanges
• Forgings
• Fasteners
• Custom Machined Components

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Applications of 2507

Offshore Oil & Gas

• Subsea systems
• Flowlines
• Manifolds
• Umbilicals
• Pressure vessels

Desalination

• Evaporators
• Pumps
• Seawater piping

Chemical Processing

• Heat exchangers
• Reactors
• Storage tanks

Marine Engineering

• Propeller shafts
• Seawater systems
• Marine piping

Pulp & Paper

• Bleaching systems
• Digesters

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Duplex 2507 vs Other Stainless Steels

Alloy	Yield Strength	PREN	Main Advantage
2507	550 MPa	>40	Maximum Corrosion Resistance
2205	450 MPa	35	General Duplex Applications
316L	170 MPa	25	General Corrosion Resistance
904L	220 MPa	35	Acid Resistance

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Welding & Fabrication

Welding

Suitable welding methods include:

• GTAW (TIG)
• GMAW (MIG)
• SMAW
• SAW

Use matching super duplex filler metals to maintain phase balance and corrosion resistance.

Fabrication

• Excellent hot workability
• Good cold forming capability
• Higher strength requires greater forming forces than austenitic grades

Heat Treatment

Solution annealing:

1025–1125°C
Rapid water quench

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Standards & Equivalent Grades

Standard	Designation
UNS	S32750
EN / W.Nr.	1.4410
ASTM Forging Grade	A182 F53
ASTM Plate	A240 S32750
ASTM Bar	A479 S32750
ISO	X2CrNiMoN25-7-4

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Frequently Asked Questions

What is Duplex Stainless Steel 2507?

2507 is a super duplex stainless steel combining high strength with exceptional resistance to chloride-induced corrosion.

What is the UNS designation of 2507?

The UNS number is UNS S32750.

What is the difference between 2507 and 2205?

2507 contains higher chromium, molybdenum, and nitrogen, providing significantly better pitting and crevice corrosion resistance.

Is 2507 suitable for seawater service?

Yes. 2507 is widely used in seawater systems, offshore platforms, and desalination plants.

What is the PREN of 2507?

The PREN value typically exceeds 40.

Can 2507 replace nickel alloys?

In many chloride-containing environments, 2507 provides sufficient corrosion resistance at a lower cost than nickel alloys.

Is 2507 magnetic?

Yes. Due to its ferritic phase content, 2507 exhibits magnetic properties.

Can Duplex 2507 be welded?

Yes. Proper welding procedures and matching filler metals are recommended.

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Why Choose J&A Alloy

Comprehensive Super Duplex Inventory

Available in bars, plates, sheets, pipes, tubes, forgings, and custom components.

Strict Quality Assurance

• PMI Testing
• Chemical Analysis
• Mechanical Testing
• Corrosion Testing
• Ultrasonic Inspection

Full Material Certification

• EN 10204 3.1
• MTC
• NACE Compliance Documentation
• Third-Party Inspection

Custom Manufacturing

• Precision Machining
• Forging
• Cut-to-Size Processing
• Fast Delivery

Global Export Experience

Serving offshore, marine, chemical processing, desalination, and energy industries worldwide.