ASME SA789 UNS S31803 / 1.4462 Duplex 2205 Stainless Steel Seamless Tube

Overview:

S31803 is a duplex stainless steel often used for seamless tubes. This grade combines the best features of both austenitic and ferritic steels, resulting in excellent mechanical properties and corrosion resistance. The typical composition includes approximately 22% chromium, 5% nickel, and 3% molybdenum, which enhances its ability to withstand pitting and crevice corrosion, especially in harsh environments.

In applications where strength and corrosion resistance are crucial, S31803 excels, making it a popular choice in the chemical processing, oil and gas, and marine industries. The duplex microstructure provides a good balance of toughness and strength, allowing it to perform well at both ambient and elevated temperatures.

Additionally, S31803 exhibits favorable weldability, although some precautions are necessary to avoid issues like sigma phase formation during high-temperature welding processes. Its excellent mechanical properties include a high yield strength compared to standard austenitic grades, which allows for thinner walls in tube applications, reducing weight without compromising safety or integrity.

Specification:

Chemical Composition:

Mechanical Properties:
 

Applications:

1. Oil and Gas Industry
- Used in offshore platforms, subsea pipelines, and heat exchangers due to resistance to chloride stress corrosion.

2. Chemical Processing
- Suitable for equipment handling aggressive chemicals, including reactors, heat exchangers, and storage tanks.

3. Marine Applications
- Ideal for components exposed to seawater, such as pump shafts, valves, and piping systems.

4. Power Generation
- Used in cooling systems, especially in nuclear and fossil fuel plants where corrosion resistance is critical.

5. Pulp and Paper Industry
- Employed in chemical recovery systems and other processing equipment that face corrosive conditions.

6. Food and Beverage Processing
- Utilized in components that require high sanitation standards and resistance to corrosion.

7. Desalination Plants
- Perfect for seawater reverse osmosis facilities, where durability and corrosion resistance are essential.

8. Pharmaceuticals
- Used in equipment where hygienic conditions and resistance to cleaning agents are crucial.