Duplex Stainless Steel 2205 (UNS S32205 / S31803)

Duplex Stainless Steel 2205 is a nitrogen-enhanced duplex stainless steel engineered to provide an exceptional combination of corrosion resistance and mechanical strength. Its dual-phase microstructure consists of approximately 50% ferrite and 50% austenite, resulting in superior chloride corrosion resistance and higher strength than standard stainless steels.

2205 has become the industry standard duplex grade for demanding environments where traditional stainless steels are insufficient, but super duplex grades such as 2507 are not economically justified.

---

2205 At a Glance

Key Attribute	Value
Material	Duplex Stainless Steel 2205
UNS Number	S32205 / S31803
EN / W.Nr.	1.4462
Material Type	Duplex Stainless Steel
Microstructure	50% Austenite / 50% Ferrite
Density	7.8 g/cm³
PREN	34–36
Yield Strength	≥ 450 MPa
Main Advantage	Strength + Chloride Corrosion Resistance
Typical Industries	Oil & Gas, Chemical, Marine, Desalination

---

Features of 2205

• Excellent chloride pitting resistance
• Outstanding crevice corrosion resistance
• Superior chloride stress corrosion cracking resistance
• Approximately twice the yield strength of 316L
• High fatigue strength
• Good erosion-corrosion resistance
• Excellent weldability
• Cost-effective alternative to nickel alloys
• Good resistance to sour service environments
• Excellent combination of strength and corrosion resistance

---

Chemical Composition of 2205

Element	Content (%)
Chromium (Cr)	22.0 – 23.0
Nickel (Ni)	4.5 – 6.5
Molybdenum (Mo)	3.0 – 3.5
Nitrogen (N)	0.14 – 0.20
Manganese (Mn)	≤ 2.0
Silicon (Si)	≤ 1.0
Carbon (C)	≤ 0.03
Phosphorus (P)	≤ 0.03
Sulfur (S)	≤ 0.02
Iron (Fe)	Balance

---

Physical Properties of 2205

Property	Value
Density	7.80 g/cm³
Melting Range	1385 – 1440°C
Electrical Resistivity	0.85 μΩ·m
Thermal Conductivity	19 W/m·K
Specific Heat Capacity	500 J/kg·K
Modulus of Elasticity	200 GPa

---

Mechanical Properties of 2205

Property	Metric Value
Tensile Strength	≥ 620 MPa
Yield Strength (0.2%)	≥ 450 MPa
Elongation	≥ 25%
Hardness	≤ 290 HB

(Annealed Condition)

---

Corrosion Resistance

2205 exhibits excellent resistance to:

• Chloride pitting corrosion
• Crevice corrosion
• Chloride stress corrosion cracking
• Sulfide stress cracking
• Organic acids
• Industrial seawater systems

Compared with 316L stainless steel, Duplex 2205 provides substantially improved corrosion resistance and significantly longer service life in chloride-containing environments.

---

High Temperature Performance

2205 is primarily designed for corrosion resistance rather than elevated-temperature service.

Recommended Service Range

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

Extended exposure above 300°C may reduce toughness and phase stability.

---

Available Forms

J&A Alloy supplies Duplex Stainless Steel 2205 in:

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

---

Applications of 2205

Oil & Gas

• Pressure vessels
• Separators
• Heat exchangers
• Process piping

Chemical Processing

• Storage tanks
• Reactors
• Heat exchangers

Marine Engineering

• Seawater piping
• Offshore structures
• Pump shafts

Desalination Plants

• Evaporators
• Seawater handling systems

Pulp & Paper

• Digesters
• Bleaching equipment

---

Duplex 2205 vs Other Stainless Steels

Grade	Yield Strength	PREN	Main Advantage
2205	450 MPa	34–36	Strength & Corrosion Balance
316L	170 MPa	24–26	General Corrosion Resistance
904L	220 MPa	34–35	Acid Resistance
2507	550 MPa	>40	Maximum Chloride Resistance

---

Welding & Fabrication

Welding

Recommended methods:

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

Use duplex-compatible filler metals to maintain proper ferrite-austenite balance.

Heat Treatment

Solution Annealing:
1020–1100°C
Rapid Water Quench

Fabrication

2205 can be hot formed and cold worked, although its higher strength requires greater forming forces than austenitic grades.

---

Standards & Equivalent Grades

Standard	Designation
UNS	S32205 / S31803
EN / W.Nr.	1.4462
ASTM Forging Grade	A182 F51
ASTM Plate	A240 S32205
ASTM Bar	A479 S32205
ISO	X2CrNiMoN22-5-3

---

Frequently Asked Questions

What is Duplex Stainless Steel 2205?

2205 is a duplex stainless steel combining ferritic and austenitic microstructures for enhanced strength and corrosion resistance.

What is the UNS designation of 2205?

2205 is designated as UNS S32205 and UNS S31803.

Is Duplex 2205 better than 316L?

Yes. Duplex 2205 offers significantly higher strength and better resistance to pitting, crevice corrosion, and chloride SCC.

Can Duplex 2205 be used in seawater?

Yes. It performs well in many seawater applications and marine environments.

What is the PREN value of 2205?

Typically between 34 and 36.

Is Duplex 2205 magnetic?

Yes. Because of its ferritic phase content, it exhibits magnetic properties.

Can Duplex 2205 be welded?

Yes. Proper welding procedures and filler metals are recommended.

What is the difference between 2205 and 2507?

2507 offers higher strength and corrosion resistance, while 2205 provides a more economical solution for many industrial applications.

---

Why Choose J&A Alloy

Duplex Stainless Steel Specialist

Extensive inventory of duplex and super duplex stainless steels for global industrial projects.

Quality Assurance

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

Full Certification

• EN 10204 3.1
• Mill Test Certificate
• NACE Documentation
• Third-Party Inspection

Manufacturing Capabilities

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

Global Supply Experience

Serving oil & gas, offshore, chemical processing, marine, desalination, and power generation industries worldwide.