A790 duplex stainless steel pipe is a special type of stainless steel pipe, whose microstructure is mainly composed of austenite and ferrite. The austenite phase provides good toughness, corrosion resistance, high strength and good processability, while the ferrite phase enhances the steel’s resistance to stress corrosion cracking, thermal conductivity and resistance to chloride stress corrosion cracking. Therefore, duplex stainless steel pipes usually have the characteristics of high strength, good corrosion resistance, excellent welding performance and high thermal conductivity.
Duplex stainless steel pipes also have a lower linear expansion coefficient, which gives it better dimensional stability at high temperatures. These characteristics make duplex stainless steel pipes widely used in petroleum, chemical, seawater desalination, papermaking, and many other industrial fields.
Specification of Duplex Stainless Steel Pipes
Processing Method | Seamless and Welded |
Size Range | 1/8” – 48” / DN6 – 750 |
Thickness Schedule | SCH 10S- SCH 160, XXS |
Length | 6m or 12 m or Random |
Standard | ASME B36.19 |
Surface Treatment | Polish , Mirror , Epoxy Powder FBE, 2PE, 3PE Coating |
Material Grade | ASTM A790 S32205, S31803, 32750, 32760, S32550 |
Materials of Duplex Stainless Steel Pipes
Chemical Composition
CHEMICAL | LIMITS | C | Mn | P | S | Si | Ni | Cr | Mo | N | Cu |
ASTM A790 S31803 | MIN | 4.5 | 21.00 | 2.50 | 0.08 | ||||||
MAX | 0.03 | 2.00 | 0.03 | 0.02 | 1.00 | 6.5 | 23.00 | 3.50 | 0.20 | ||
ASTM A790 UNS S32205 | MIN | 4.50 | 22.00 | 3.00 | 0.14 | ||||||
MAX | 0.03 | 2.00 | 0.030 | 0.020 | 1.00 | 6.50 | 23.00 | 3.50 | 0.20 | ||
ASTM A790 UNS S32750 | MIN | 6.00 | 24.00 | 3.00 | 0.24 | ||||||
MAX | 0.030 | 1.20 | 0.035 | 0.020 | 0.80 | 8.00 | 26.00 | 5.00 | 0.32 | 0.5 | |
ASTM A790 S32760 | MIN | 24.00 | 3.00 | ||||||||
MAX | 0.03 | 1.00 | 0.03 | 26.00 | 4.00 |
Mechanical Properties
MATERIAL | T.S (MPA) | Y.S (MPA) | EL % | HARDNESS |
ASTM A790 S31803 | 620min | 450min | 25min | 290max |
ASTM A790 S32205 | 655min | 450min | 25 min | 290max |
ASTM A790 S32750 | 800min | 550min | 15min | 310max |
ASTM A790 S32760 | 750min | 550min | 25min |
Application Fields
Oil and Gas Industry
Used in oil well pipes, oil pipelines and natural gas pipelines. In deep-sea oil extraction, duplex stainless steel pipes can withstand the erosion of high-pressure, high-salinity seawater and corrosive media such as hydrogen sulfide, ensuring the safe transportation of oil and natural gas.
Chemical Industry
In chemical plants, it is used to transport various corrosive chemicals such as acids, alkalis, and salt solutions. For example, in the chlor-alkali industry, duplex stainless steel pipes can be used to transport corrosive media such as chlorine-containing brine and sodium hydroxide solution.
Marine Engineering
Duplex stainless steel pipes are widely used in offshore platform structural parts, seawater cooling system pipelines, seawater desalination equipment, etc. Due to its excellent seawater corrosion resistance and high strength, it can improve the service life and reliability of marine engineering facilities.
Construction Industry
Duplex stainless steel pipes are also used in some building structures that require corrosion resistance and aesthetics, such as the supporting structure of the building curtain wall, indoor and outdoor decorative railings, etc. Its good corrosion resistance can reduce maintenance costs, and its beautiful appearance meets the design requirements of modern buildings.