Stainless Steel Duplex 2205
Stainless Steel Duplex 2205 (UNS S31803 / S32205 / EN 1.4462)
Stainless Steel Duplex 2205 (UNS S31803 / S32205 / EN 1.4462) is a duplex stainless steel with a balanced austenitic-ferritic microstructure. This combination provides an excellent balance of high mechanical strength, corrosion resistance, toughness, and durability.
With its chromium, nickel, molybdenum, and nitrogen content, Duplex 2205 offers excellent resistance to general corrosion, pitting corrosion, crevice corrosion, and chloride-induced stress corrosion cracking.
Compared with conventional austenitic stainless steels such as 304L and 316L, Duplex 2205 generally provides a significantly higher yield strength. This can allow engineers to reduce material thickness and component weight in certain applications.
Duplex 2205 is widely used in oil & gas, petrochemical, chemical processing, marine, offshore, power generation, desalination, and water-treatment industries.
Emirerri Steel supplies Stainless Steel Duplex 2205 in sheets, plates, coils, pipes, tubes, round bars, flanges, and pipe fittings for customers across Tunisia, Algeria, Morocco, Libya, and international markets.
Key Features
- Duplex austenitic-ferritic microstructure
- Excellent corrosion resistance
- Excellent resistance to chloride-induced stress corrosion cracking
- Excellent pitting resistance
- Excellent crevice corrosion resistance
- High yield strength
- High tensile strength
- Good fatigue resistance
- Good erosion and abrasion resistance
- Good resistance in marine environments
- Good weldability with appropriate procedures
- Excellent chloride resistance
- High strength-to-weight ratio
Specifications
| Specification | Details |
|---|---|
| Grade | Duplex Stainless Steel 2205 |
| UNS | S31803 / S32205 |
| Werkstoff Number | 1.4462 |
| EN Designation | X2CrNiMoN22-5-3 |
| Type | Duplex Stainless Steel |
| Microstructure | Austenite + Ferrite |
| Common Standards | ASTM A240, ASTM A276, ASTM A790, ASTM A789, ASTM A182, EN 10088 |
| Supply Condition | Solution Annealed |
| Surface Finishes | No.1, 2B, BA, No.4, Mirror |
| Product Forms | Sheet, Plate, Coil, Pipe, Tube, Round Bar, Flanges, Pipe Fittings |
Equivalent Grades of Duplex 2205
| Standard | Equivalent Grade |
|---|---|
| ASTM / UNS | S31803 / S32205 |
| EN | 1.4462 |
| EN Designation | X2CrNiMoN22-5-3 |
| DIN | X2CrNiMoN22-5-3 |
| JIS | SUS329J3L / SUS329J4L* |
| ISO | X2CrNiMoN22-5-3 |
*Equivalent grades should be verified according to the product form and applicable project standard. UNS S32205 represents the commonly specified optimized chemistry for modern Duplex 2205.
Available Sizes
Duplex 2205 Sheets & Plates
- Thickness: 0.5 to 100 mm
- Width: Up to 2500 mm
- Length: Up to 12000 mm
Duplex 2205 Pipes & Tubes
- Outside Diameter: 6 to 610 mm
- Wall Thickness: 0.5 to 40 mm
Duplex 2205 Round Bars
- Diameter: 6 to 500 mm
Available dimensions depend on product form, manufacturing standard, supply condition, and project requirements.
Duplex 2205 Chemical Composition
| Element | Composition (%) |
|---|---|
| Chromium (Cr) | 22.0 – 23.0 |
| Nickel (Ni) | 4.5 – 6.5 |
| Molybdenum (Mo) | 3.0 – 3.5 |
| Nitrogen (N) | 0.14 – 0.20 |
| Carbon (C) | ≤ 0.030 |
| Manganese (Mn) | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.030 |
| Sulfur (S) | ≤ 0.020 |
| Iron (Fe) | Balance |
Duplex 2205 Mechanical Properties of
Values may vary according to product form and applicable standard.
| Property | Typical / Minimum Value |
|---|---|
| Tensile Strength | ≥ 620 MPa |
| Yield Strength (0.2% Offset) | ≥ 450 MPa |
| Elongation | ≥ 25% |
| Hardness | ≤ 310 HB |
| Modulus of Elasticity | ≈ 200 GPa |
The yield strength of Duplex 2205 is generally significantly higher than that of standard austenitic stainless steels such as 304L and 316L.
Duplex 2205 Physical Properties
| Property | Approximate Value |
|---|---|
| Density | 7.8 g/cm³ |
| Melting Range | ≈ 1350 – 1400°C |
| Thermal Conductivity | ≈ 19 W/m·K |
| Specific Heat Capacity | ≈ 500 J/kg·K |
| Modulus of Elasticity | ≈ 200 GPa |
| Magnetic Permeability | Higher than austenitic grades |
Because Duplex 2205 contains a significant ferritic phase, it is magnetic, unlike fully austenitic stainless steels, which are generally non-magnetic in the annealed condition.
Types of Duplex 2205 Products
Duplex 2205 Sheets & Plates
Used for storage tanks, pressure vessels, chemical equipment, offshore structures, and industrial fabrication.
Duplex 2205 Pipes & Tubes
Used in offshore piping, oil and gas systems, chemical processing, desalination, and corrosive fluid-handling applications.
Duplex 2205 Heat Exchanger Tubes
Suitable for heat exchangers, condensers, and equipment exposed to chloride-containing or corrosive fluids.
Duplex 2205 Round Bars
Used for shafts, valves, pumps, fasteners, machined components, and mechanical parts.
Duplex 2205 Flanges & Pipe Fittings
Used in high-pressure piping systems and corrosive industrial environments.
Corrosion Resistance
Corrosion resistance is one of the main advantages of Duplex 2205.
It provides excellent resistance to:
- General corrosion
- Pitting corrosion
- Crevice corrosion
- Chloride-induced stress corrosion cracking
- Chloride-containing environments
- Seawater
- Marine atmospheres
- Many chemical environments
Duplex 2205 typically has a PREN (Pitting Resistance Equivalent Number) above 30, supporting its strong resistance to localized corrosion.
For extremely aggressive chloride environments, Super Duplex 2507 or other higher-alloy grades may be considered.
Heat Resistance
Duplex 2205 has good oxidation resistance and retains high mechanical strength at moderate temperatures.
However, prolonged exposure to certain elevated-temperature ranges can cause the formation of undesirable intermetallic phases, particularly sigma phase, which can significantly reduce toughness and corrosion resistance.
Therefore, Duplex 2205 is generally not selected for prolonged service at very high temperatures.
For high-temperature applications, material selection should be based on the actual operating temperature and duration of exposure.
Heat Treatment
Solution Annealing
Duplex 2205 is generally solution annealed at approximately:
1020 – 1100°C
followed by rapid cooling.
Objectives
- Restore the austenite-ferrite balance
- Dissolve unwanted intermetallic phases
- Optimize corrosion resistance
- Improve ductility
- Relieve internal stresses
Heat treatment must be carefully controlled because the duplex microstructure is sensitive to thermal exposure.
Welding
Duplex 2205 has good weldability when suitable welding procedures are followed.
Recommended Welding Processes
- GTAW / TIG
- GMAW / MIG
- SMAW
- SAW
- FCAW
- Orbital Welding
Important Welding Considerations
Control of heat input and interpass temperature is important to maintain an appropriate ferrite-austenite balance.
Improper welding can result in:
- Excessive ferrite
- Reduced toughness
- Reduced corrosion resistance
- Formation of undesirable intermetallic phases
Welding procedures should therefore be qualified according to the applicable standards and project specifications.
Fabrication
Machining
- Turning
- Milling
- Drilling
- Threading
Duplex 2205 has higher strength than conventional austenitic stainless steels and can therefore be more difficult to machine.
Forming
- Bending
- Roll forming
- Cold forming
- Deep drawing
- Press forming
Higher forming forces may be required because of its high yield strength.
Cutting
- Laser cutting
- Plasma cutting
- Waterjet cutting
- Mechanical sawing
Surface Finishing
- Pickling
- Passivation
- Mechanical polishing
- Electropolishing
Applications
Oil & Gas Industry
- Offshore piping
- Production equipment
- Separators
- Process systems
- Pressure equipment
- Subsea components
Petrochemical Industry
- Storage tanks
- Heat exchangers
- Process piping
- Chemical processing equipment
Chemical Industry
- Chemical reactors
- Storage tanks
- Process piping
- Pressure vessels
Desalination & Water Treatment
- Desalination plants
- Pumps
- Piping systems
- Water-treatment equipment
- Reverse-osmosis equipment
Marine Industry
- Marine equipment
- Seawater piping
- Offshore structures
- Shipbuilding components
Power Generation
- Heat exchangers
- Cooling systems
- Auxiliary equipment
- Industrial piping
Duplex 2205 in Tunisia, Algeria, Morocco & Libya
Stainless Steel Duplex 2205 is particularly suitable for industrial projects across Tunisia, Algeria, Morocco, and Libya where high mechanical strength and excellent corrosion resistance are required.
It is well suited to oil & gas, petrochemical, chemical processing, desalination, water treatment, marine, offshore, and power-generation applications.
For North African projects exposed to chlorides, seawater, corrosive process fluids, or demanding mechanical loads, Duplex 2205 can provide a strong alternative to conventional austenitic stainless steels when selected according to actual service conditions.
Duplex 2205 vs 316L
| Property | Duplex 2205 | Stainless Steel 316L |
|---|---|---|
| Microstructure | Austenite + Ferrite | Austenitic |
| Yield Strength | ≥ 450 MPa | ≥ 170 MPa* |
| Corrosion Resistance | Excellent | Very Good |
| Chloride Resistance | Excellent | Good to Very Good |
| Stress Corrosion Cracking Resistance | Excellent | More Limited |
| Magnetic | Yes | Generally Non-Magnetic |
| Strength-to-Weight Ratio | High | Moderate |
| Typical Cost | Variable | Generally Lower |
*Indicative value; exact requirements depend on product form and applicable standard.
Conclusion
Stainless Steel Duplex 2205 (UNS S31803 / S32205 / EN 1.4462) is a high-performance duplex stainless steel combining the advantages of austenitic and ferritic stainless steel structures.
Its high yield strength, excellent chloride resistance, resistance to stress corrosion cracking, pitting resistance, and strong mechanical performance make it an excellent choice for demanding industrial environments.
Available in sheets, plates, pipes, tubes, round bars, flanges, and pipe fittings, Duplex 2205 provides reliable performance in oil & gas, petrochemical, chemical, desalination, marine, water treatment, offshore, and power-generation industries across Tunisia, Algeria, Morocco, Libya, and international markets.
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