Duplex and Super Duplex
This group of highly versatile alloys combine the key properties of Austenitic and Ferritic grades. They are strong, corrosion-resistant, and able to withstand high temperatures and pressures, making it an ideal choice for use in harsh environments
Available in strip and wire
Duplex Stainless Steels have a dual Austenitic-Ferritic structure, offering a combination of superior properties compared to other Stainless Steel grades. These alloys provide improved corrosion resistance, particularly against pitting, crevice corrosion, and stress corrosion cracking, with nearly twice the strength of Austenitic Stainless Steels and improved toughness and ductility over Ferritic grades. With a lower alloying costs due to balanced austenitic-ferritic microstructure, these alloys provide manufacturers with a low cost alternative solution. Duplex stainless steel is perfect for demanding applications where resistance to corrosion and erosion is critical.
Available Duplex And Super Duplex
What are the benefits of using Duplex And Super Duplex?
High strength and toughness
Excellent corrosion resistance
Improved resistance to pitting and crevice corrosion
Enhanced resistance to stress corrosion cracking
Low cost alternative to austenitic and ferritic stainless steels
High resistance to chloride-induced corrosion
Suitable for demanding applications in oil, gas, and marine industries
Suitable for work hardening
Magnetic
What are the disadvantages of using Duplex And Super Duplex?
Less resistant to corrosion and inferior toughness when compared to Austenitic and Ferritic grades.
Limited formability and welding capabilities.
Limited uses in applications above 250°C, as harmful intermetallic phases may form during long exposures.
Impact toughness decreases significantly at extremely low temperatures
Discover the Advantages of Duplex Stainless Steel for High-Performance Manufacturing Solutions
Duplex Stainless Steel, a unique combination of Austenitic and Ferritic structures, offers manufacturers a range of benefits, including enhanced strength, corrosion resistance, and cost-effectiveness. With its dual-phase microstructure, Duplex Stainless Steel provides an ideal solution for various demanding applications.
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Benefits of Duplex Stainless Steel:
- Dual Austenitic-Ferritic structure for balanced properties
- Higher annealed strengths for improved durability
- Enhanced stress relaxation and fatigue properties
- Superior tensile strength for demanding applications
- Greater corrosion and pitting resistance for extended service life
- Lighter weight compared to other stainless steel grades
- Lower cost alternative to Austenitic Stainless Steels
While these magnetic alloys are not hardenable by heat treatment, they offer many additional advantages over other stainless steels. Manufacturers choose these alloys for a wide range of applications due to their higher annealed strengths, stress relaxation and fatigue properties, superior tensile strength, excellent corrosion and pitting resistance and lighter weight. These alloys gain their mechanical strength from alloying with nitrogen; higher strength supports weight reduction. This, in turn, offers environmental benefits over other Steels as the lower weight reduces transport and assembly costs.
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Super Duplex: The Ultimate Choice for Extreme Environments
Super Duplex offers additional benefits for even more demanding applications, thanks to its higher chromium content. This advanced material provides enhanced mechanical properties and superior corrosion resistance, making it the perfect choice for challenging environments where other materials may falter. Super Duplexes are a popular choice for the Marine, Petrochemical, and Nuclear Power Generation sectors.
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Super Alloys
As a result of their attractive combination of properties, Duplexes are commonly described as Super Alloys. These Super Alloys can be strengthened by cold work and has lower thermal expansion and higher heat conductivity than Austenitic Steel strip. They also provide a low cost alternative to Austenitic Stainless Steels, owing to their lower nickel content.
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Innovative Material DevelopmentÂ
Since the inception of Duplex Stainless Steel in the 1920s, ongoing advancements in material development have created additional Duplex alloys. Greater control of the nitrogen alloying element has made Duplexes a progressively popular choice in modern manufacturing. As the applications for Super Alloys rise, demand is increasing, incentivising the development and release of additional grades. We work closely with the mills to ensure the Knight Group offers the latest material development innovations, ensuring you keep your competitive edge.
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Take Your Manufacturing to the Next Level with Duplex Stainless Steel
Contact the Knight Group today to learn more about the benefits of Duplex Stainless Steel and how it can revolutionise your manufacturing processes. As specialist Stainless Steel suppliers, we supply precision strip and precision wire in a range of Duplex grades. Our team of experts is ready to help you find the perfect material solution for your unique application.
| CHEMICAL COMPOSITION OF DUPLEX STAINLESS STEEL | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| European Designation EN 10088-2 2014 | Former BS Standard (Wire Only) | American Designation (ASTM) | TYPICAL CHEMICAL COMPOSITION % | ||||||||||||
| Number | Name | BS 1554 1990 nearest fit | AISI nearest fit | UNS nearest fit | C | Si | Mn | P | S | Cr | Mo | Ni | N | Cu | Other |
| 1.4062 | - | - | 2202 | S 32202 | 0.03 | 1.0 | 2.0 | 0.04 | 0.01 | 21.5 - 24.0 | 0.45 | 1.0 - 2.9 | 0.16 - 0.28 | - | - |
| 1.4462 | X2CrNiMoN22–5-3 | - | 2205 | S 32205 | 0.03 | 1.0 | 2.0 | 0.035 | 0.015 | 21.0 - 23.0 | 2.5 - 35 | 4.5 - 6.5 | 0.1 - 0.22 | - | - |
| 1.4362 | X2CrNiN23–4 | - | 2304 | S 32304 | 0.03 | 1.0 | 2.0 | 0.035 | 0.015 | 22.0 - 24.5 | 0.1 - 0.6 | 3.5 - 5.5 | 0.05 - 0.20 | 0.1 - 0.6 | - |
| 1.4410 | X2CrNiMoN25–7-4 | - | 2507 | S 32750 | 0.03 | 1.0 | 2.0 | 0.035 | 0.015 | 24.0 - 26.0 | 3.0 - 4.5 | 6.0 - 8.0 | 0.24 - 0.35 | - | - |
| 1.4662 | X2CrNiMoN22–5-3 | - | (LDX) 2404 | S 82441 | 0.03 | 0.7 | 2.5 - 4.0 | 0.035 | 0.005 | 23.0 - 25.0 | 1.0 - 2.0 | 3.0 - 4.5 | 0.2 - 0.3 | 0.1 - 0.8 | - |
| 1.4162 | X2CrMnNiN21–5-1 | - | (LDX) 2101 | S 32101 | 0.04 | 1.0 | 4.0 - 6.0 | 0.04 | 0.015 | 21.0 - 22.0 | 0.1 - 0.8 | 1.35 - 1.90 | 0.20 - 0.25 | 0.1 - 0.8 | - |
| MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL STRIP | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| European Designation EN 10088-2 2014 | Former BS Standard (Wire Only) | American Designation (ASTM) | Proof Strength 0.2% Min (N/mm2) | Tensile Strength | Elong. % Min. (50mm Gauge Length) | Hardness Max (VPN) | Surface Finish | ||
| Number | Name | BS 1554 1990 nearest fit | AISI nearest fit | UNS nearest fit | |||||
| 1.4062 | - | - | 2202 | S 32202 | 380 | 650 - 900 | 30 | 305 | 2B & 2R |
| 1.4462 | X2CrNiMoN22–5-3 | - | 2205 | S 32205 | 450 | 650 - 880 | 25 | 284 | 2B & 2R |
| 1.4362 | X2CrNiN23–4 | - | 2304 | S 32304 | 400 | 600 - 830 | 25 | 274 | 2B & 2R |
| 1.4410 | X2CrNiMoN25–7-4 | - | 2507 | S 32750 | 530 | 730 - 950 | 25 | 305 | 2B & 2R |
| 1.4662 | X2CrNiMoN22–5-3 | - | (LDX) 2404 | S 82441 | 450 | 650 - 900 | 25 | 305 | 2B & 2R |
| 1.4162 | X2CrMnNiN21–5-1 | - | (LDX) 2101 | S 32101 | 400 | 650 - 900 | 25 | 305 | 2B & 2R |
| MECHANICAL PROPERTIES OF DUPLEX STAINLESS STEEL WIRE | ||||||||
|---|---|---|---|---|---|---|---|---|
| European Designation EN 10088-2 2014 | Former BS Standard (Wire Only) | American Designation (ASTM) | Maximum tensile strength N/mm² | |||||
| Number | Name | BS 1554 1990 nearest fit | AISI nearest fit | UNS nearest fit | Wire dia 13.0 – 6.0mm | Wire dia 6.00 – 1.50mm | Wire dia 1.50 – 0.50mm | Wire dia 0.50 – 0.10mm |
| 1.4062 | - | - | 2202 | S 32202 | Not available as wire. Strip products available. | |||
| 1.4462 | X2CrNiMoN22–5-3 | - | 2205 | S 32205 | Available on request. | |||
| 1.4362 | X2CrNiN23–4 | - | 2304 | S 32304 | Not available as wire. Strip products available. | |||
| 1.4410 | X2CrNiMoN25–7-4 | - | 2507 | S 32750 | Not available as wire. Strip products available. | |||
| 1.4662 | X2CrNiMoN22–5-3 | - | (LDX) 2404 | S 82441 | Not available as wire. Strip products available. | |||
| 1.4162 | X2CrMnNiN21–5-1 | - | (LDX) 2101 | S 32101 | Not available as wire. Strip products available. | |||
| MATERIAL FEATURES AND APPLICATIONS OF DUPLEX STAINLESS STEEL | |||||||
|---|---|---|---|---|---|---|---|
| European Designation EN 10088-2 2014 | Former BS Standard (Wire Only) | American Designation (ASTM) | Key Features | Key Markets | Applications | ||
| Number | Name | BS 1554 1990 nearest fit | AISI nearest fit | UNS nearest fit | |||
| 1.4062 | - | - | 2202 | S 32202 | Duplex 2202 (1.4062) is a dual-phase Austenitic-Ferritic Stainless Steel. It offers elevated yield strength, with good resistance to stress corrosion cracking. This alloy offers good mechanical strength and is suitable for cold forming. | Pulp & Paper Industry, Water, Food, Construction, Automotive, Desalination | crash barriers, desalination cladding of paper machines, oil tanks juice tanks, automotive structures |
| 1.4462 | X2CrNiMoN22–5-3 | - | 2205 | S 32205 | Duplex grade 2205 (1.4062) is a dual-phase Austenitic-Ferritic Stainless Steel. It is the most widely used Duplex grade, achieving high yield strength while maintaining sufficient ductility. With good weldability and formability, it also offers high design strength, allowing for a reduction in section thickness. The corrosion resistance is comparable to Austenitic grades 304 (1.4301) and 301 (1.4310) demonstrating outstanding resistance to stress-corrosion cracking, crevice, pitting, erosion and general corrosion even in the most severe environments. | Automotive, Chemical Processing, Transport, Springs & Pressings, Decorative, Oil and Gas, Marine | pulp and paper processing, desalination, automotive trim, offshore platforms, oil and gas processing equipment chemical processing, transport applications |
| 1.4362 | X2CrNiN23–4 | - | 2304 | S 32304 | Duplex Grade 2304 (1.4362) is a dual-phase Austenitic-Ferritic Stainless Steel with low carbon content. It proves good resistance to corrosion with comparable corrosion resistance to Austenitic grade 316L (1.4404/ 1.4432). However it has superior mechanical properties, offering much higher proof strength compared to both Austenitic Stainless Steels 304 (1.4301) and 316L (1.4404/ 1.4432). It has weight saving benefits in certain applications and is well suited for pressure vessel applications. It can operate in temperatures between -50°C (-58°F) and 300°C (572°F). Other properties include good weldability and good toughness. | Automotive, Chemical Processing, Transport, Paper and Pulp, Food Processing | pulp and paper processing, pressure vessels, desalination, automotive trim, chemical processing, transport applications |
| 1.4410 | X2CrNiMoN25–7-4 | - | 2507 | S 32750 | Duplex 2507 (1.4410) is considered a super duplex grade. As a dual-phase Austenitic-Ferritic Stainless Steel, it provides superior resistance to all corrosion with excellent protection from chloride stress corrosion cracking. It is ideally suited for service in highly corrosive conditions. It also benefits from high thermal conductivity, and a low coefficient of thermal expansion alongside high mechanical strength and good weldability. However, it is not recommended for applications requiring prolonged exposure to temperatures above 299.°C (570 °F) due to a potential reduction in toughness. | Automotive, Chemical Processing, Marine, Oil and Gas | pulp and paper processing, desalination, automotive trim, seawater systems, heat exchangers, oil and gas equipment, offshore platforms, chemical processing, vessels, piping, desalination |
| 1.4662 | X2CrNiMoN22–5-3 | - | (LDX) 2404 | S 82441 | Duplex Alloy (LDX) 2404 (1.4662) is an Austenitic-Ferritic Stainless Steel with high contents of Chromium and Nitrogen. This alloy offers both high corrosion resistance and a higher mechanical strength when compared to other common Duplex materials. Other properties include good fatigue resistance and good weldability, making it ideal for multiple applications. | Automotive, Chemical Processing, Marine, Oil and Gas, Energy, Architectural | structural components, piping systems, pulp and paper processing, heat exchangers, water treatment and desalination, offshore platforms, storage tanks, pressure vessels |
| 1.4162 | X2CrMnNiN21–5-1 | - | (LDX) 2101 | S 32101 | Duplex Alloy (LDX) 2101 (1.4162) is a low-alloyed, general purpose Austenitic-Ferritic Stainless Steel. It offers good general corrosion resistance, high sulphide and chloride stress corrosion resistance and overall good strength and weldability. | Chemical, Water Treatment, Paper & Pulp | chemical processing vessels and piping. pulp and paper mill equipment, water treatment tanks |
Precision Processing Options for Duplex Grades
All data is provided for informational purposes only. In no event will the Knight Group and its subsidiaries, be liable for in respect of any action taken by any third party arising from using the information taken from our online or printed sources. Chemical and Mechanical Properties should not be construed as maximum or minimum values for specifications, nor should information be used to assess suitability for a particular use or application. The information and data provided is deemed to be accurate to the best of our knowledge and may be revised anytime without notice and assume no duty to update