ASTM A790
ASTM A790 Duplex Stainless Steel Pipe
ASTM A790 is a standard specification for seamless and welded duplex stainless steel pipe designed for corrosive and high-pressure applications. These pipes combine the benefits of ferritic and austenitic stainless steels, offering superior strength and exceptional resistance to chloride-induced corrosion.
Key Features
Duplex microstructure (50% Ferrite + 50% Austenite)
Higher strength than standard austenitic stainless steels
Excellent resistance to pitting and crevice corrosion
Superior chloride stress-corrosion cracking resistance
Good weldability & formability
Suitable for high-pressure & high-corrosion environments
Common Grades
- ASTM A790 UNS S31200
- ASTM A790 UNS S31260
- ASTM A790 UNS S31500
- ASTM A790 UNS S31803 (commonly known as Duplex 2205)
- ASTM A790 UNS S32003
- ASTM A790 UNS S32304
- ASTM A790 UNS S32550 (commonly known as Ferralium 255)
- ASTM A790 UNS S32750 (commonly known as Super Duplex 2507)
- ASTM A790 UNS S32760 (commonly known as Zeron 100)
- ASTM A790 UNS S32707
Limitations
Not recommended for continuous service above 600°F (315°C)
due to potential phase imbalanceRequires controlled heat input during welding to maintain duplex structure
Not suitable for highly reducing acids (e.g., hydrochloric acid)
Applications
Offshore oil & gas pipelines
Chemical & petrochemical processing
Desalination plants
Marine applications
Power generation
Heat exchanger & condenser systems
Water treatment and high-pressure systems