Duplex Stainless Steel Suppliers | Manufacturers
Super duplex stainless steel with PREN>40, containing 25% Cr and high molybdenum (>3.5%), high nitrogen (0.22%～0.30%) duplex steel, the main grade is UNS S32550 (UR52N+) developed by French CLI company, S32750 (SAF 2507) developed by the Swedish SANDVIK company and S32760 (Zeron 100) developed by the British company MATER+PLATT are the main grades. Their deformable materials came out in 1990 and 1991 and entered the market in recent years. The composition of these three grades of super duplex stainless steel is similar, but the difference lies in the content of tungsten and copper.
The Duplex Stainless Steel Grades
| Duplex Stainless Steel Grade | ASTM/UNS | EN | JIS |
|---|---|---|---|
| 2205 | UNS S31803 / S32205 | EN 1.4462 | SUS 329J3L |
| 2507 | UNS S32750 | EN 1.4410 | SUS 329J4L |
Stainless Steel Duplex Products
| Stainless Steel Plate | Stainless Steel Sheet | Stainless Steel Bar | Stainless Steel Structural | Stainless Steel Tubular |
|---|---|---|---|---|
| Plate Mill Plate, Diamond Plate | 2B/2D Finish, Polished Sheet, Perforated Sheet, Flat & Expanded | Round Bar, Square Bar, Hex Bar, Rolled Flat. Sheared&Edged, Half Round | Angles, Unequal Leg, Channel, Beams, Ornamental Square Tube, Ornamental Round Tube, Ornamental Rectangular Tube | Seamless Pipe, Welded Pipe, Seamless Tube, Seamless Tube |
What is Duplex Stainless Steel?
“Duplex stainless steel” is a specific type of stainless steel alloy with a unique microstructure that combines characteristics of both austenitic and ferritic stainless steel. It contains a high level of chromium (usually around 18-28%), along with molybdenum and nickel.
The microstructure of duplex stainless steel consists of roughly equal proportions of austenite and ferrite phases.
The Main Characteristics of Duplex Stainless Steel
Duplex Stainless Steel is a type of stainless steel that has a unique two-phase microstructure consisting of both austenite and ferrite. This duplex structure is achieved through a careful balance of elements such as chromium, nickel, molybdenum, and nitrogen in the alloy composition.
The main characteristics of Duplex Stainless Steel are:
1. **Corrosion Resistance:** Duplex stainless steels offer excellent corrosion resistance, making them suitable for use in aggressive environments, such as marine applications, chemical processing, and offshore oil and gas platforms.
2. **Strength:** Duplex stainless steels have higher strength compared to standard austenitic stainless steels, making them more resistant to mechanical stresses and pressure.
3. **Toughness:** These steels exhibit good toughness, enabling them to withstand impact and heavy loads.
4. **Weldability:** While duplex stainless steels are generally weldable, certain precautions need to be taken during welding to maintain the desired properties and prevent the formation of harmful phases.
5. **Chloride Stress Corrosion Cracking Resistance:** Duplex stainless steels have superior resistance to chloride stress corrosion cracking, a type of corrosion that can occur in chloride-rich environments.
6. **Cost-Effectiveness:** Duplex stainless steels provide a cost-effective alternative to more expensive nickel-based alloys while offering similar or better corrosion resistance.
Due to their unique combination of properties, duplex stainless steels are commonly used in various industries, including chemical processing, oil and gas, pulp and paper, water treatment, and desalination plants, as well as in structural components for offshore platforms and vessels. The specific grade of duplex stainless steel chosen for a particular application will depend on the specific requirements of that application.
2205 and 2507 Duplex Stainless Steel
The main differences between 2205 and 2507 duplex stainless steels lie in their chemical compositions and mechanical properties, which result in varying performance characteristics. Here are the key distinctions:
1. Chemical Composition:
– 2205 (UNS S31803 / S32205): It is duplex stainless steel with a composition that includes approximately 22% chromium, 5-6% nickel, 3% molybdenum, and about 0.2% nitrogen. It also contains small amounts of other elements like manganese, silicon, phosphorus, sulfur, and carbon.
– 2507 (UNS S32750): This is a super duplex stainless steel with a higher alloy content. It typically contains around 25% chromium, 7% nickel, 4% molybdenum, and about 0.3% nitrogen. Like 2205, it also has trace amounts of other elements.
2. Corrosion Resistance:
– 2205: It offers excellent general corrosion resistance, especially in environments containing chlorides, making it suitable for a wide range of applications in various industries.
– 2507: With its higher chromium and molybdenum content, 2507 provides even greater resistance to corrosion, especially in aggressive and chloride-rich environments, such as seawater and brackish water.
3. Strength and Toughness:
– 2205: It has good strength and toughness, making it suitable for many structural and pressure vessel applications.
– 2507: The higher alloy content of 2507 results in increased strength and improved toughness compared to 2205, making it more appropriate for heavy-duty and high-pressure applications.
4. Duplex Stainless Steel Price:
– 2507: Due to its higher alloy content, 2507 duplex stainless steel is generally more expensive than 2205.
5. Weldability:
– 2205: It exhibits good weldability and is often used in welded constructions.
– 2507: While it can be welded, its higher alloy content may make welding more challenging, and specialized welding procedures are recommended.
6. Applications:
– 2205: Commonly used in a wide range of industries, including oil and gas, chemical processing, pulp and paper, and marine applications.
– 2507: Preferred for more demanding applications that require superior corrosion resistance, such as offshore oil and gas platforms, seawater handling systems, and desalination plants.
Both 2205 and 2507 duplex stainless steels are highly versatile and have their specific areas of application based on their performance characteristics and cost considerations. The choice between the two will depend on the specific requirements of the intended application and the environmental conditions they will be exposed.