Views: 3 Author: Wang Publish Time: 2024-06-12 Origin: Site
ASTM A790 is a standard specification for duplex stainless steel pipe. It covers the standard specifications for seamless and welded duplex (austenitic ferrite) stainless steel pipes. This standard requires that the chemical composition and mechanical properties of duplex stainless steel pipes must meet the specified range.
The ASTM A790 standard has important guiding significance for the production and use of duplex stainless steel pipes, ensuring that their quality and performance can meet the needs of specific industries. ASTM A790 standard includes UNS S31803, UNS S32205, UNS S32750, and UNS S32760 duplex stainless steel materials.
The UNS S32205 is the most used in the grades. The ASTM A790 UNS S31803 Seamless Pipe is drawn and has very low absolute roughness. The pipes of this type have a smooth surface and finish so that they could easily fit into a piping. The duplex 2205 tube components produced by us have high strength and they could withstand high acidic conditions. The specialty of duplex is that it combines high corrosion resistance properties and high strength properties from the ferritic and austenitic steel characteristics. We make pipes through electric resistance weld, electric fusion weld, hot rolling and cold drawing. The electric resistance weld Duplex S31803 Erw Pipe is stronger and harder. Some of the duplex material could be cold worked and heat treated for extra strength. The WERKSTOFF NR. 1.4462 Welded Pipes are stronger and easy to weld with. We manufacture all kinds of 2205 Duplex Heat Exchanger Tube parts for different industrial use cases.
UNS S32205 is ferritic-austenitic duplex steel having a ferritic-austenitic microstructure. In the annealed state, the alloy contains around 40-50 percent ferrite. The duplex microstructure combines the toughness of ferritic grades with the corrosion resistance of austenitic grades. It is not unusual to see the metal employed as a realistic answer to the Achilles’ heel of stainless steel, chloride-induced stress cracking.
When compared to 317L stainless steel, UNS S32205 offers better resistance to chloride pitting and crevice corrosion. The alloy has excellent corrosion resistance to saltwater and most sulfuric acid concentrations. UNS S32205 duplex stainless steel is also resistant to sulfide stress corrosion cracking (sour-gas environments). The large concentrations of chromium, nitrogen, and molybdenum contained in UNS S32205 are largely ascribed to its excellent composition and hence efficiency.
UNS S31803 is a duplex stainless steel grade with a 50:50 austenite, ferrite microstructure. The material incorporates strong mechanical strength and ductility with moderate to good corrosion resistance in a variety of settings.
This Duplex Steel UNS S31803 material is typically supplied in the annealed form. The yield strength of the material in an annealed state is roughly 450 Mpa. The A276 S31803 Material alloy may be used effectively as a substitute to austenitic stainless steels of the 300 series. In fact, it may be utilized as a replacement in practically any application requiring great mechanical strength and low weight.
Grade | C | Mn | Si | P | S | Cr | Ni | Mo | N | Fe |
Duplex S31803 | 0.030 max. | 2.00 max. | 1.00 max. | 0.030 max. | 0.020 max. | 22.0 – 23.0 | 4.50 – 6.50 | 3.0 – 3.5 | 0.14 – 0.20 | 63.72 min. |
Duplex S32205 | 0.030 max. | 2.00 max. | 1.00 max. | 0.030 max. | 0.020 max. | 21.0 – 23.0 | 4.50 – 6.50 | 2.50 – 3.50 | 0.08 – 0.20 | 63.54 min |
Element | Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
Duplex S31803 | 7.805 | 0.285 | 1420 – 1465 | 2588 – 2669 | 25 min. |
Duplex S32205 | 7.805 | 0.285 | 1420 – 1465 | 2588 – 2669 | 25 min. |
ASTM A790 S31803/S32205 pipes find applications in various industries where a combination of high strength and excellent corrosion resistance is required. Some common applications include:
Oil and Gas Industry: Duplex stainless steel pipes are used extensively in upstream and downstream oil and gas operations. They are employed in offshore platforms, subsea pipelines, refineries, and petrochemical plants due to their resistance to corrosion from harsh environments, including seawater and acidic or chloride-containing fluids.
Chemical Processing: The chemical processing industry often deals with corrosive substances, high temperatures, and challenging operating conditions. ASTM A790 S31803 pipes are used in chemical plants for transporting corrosive chemicals, acids, and solvents safely and reliably.
Desalination Plants: Desalination involves treating seawater or brackish water to produce freshwater. Duplex stainless steel pipes are utilized in desalination plants for seawater intake, brine disposal, and freshwater distribution systems due to their resistance to corrosion and chloride-induced stress corrosion cracking.
Pulp and Paper Industry: Duplex stainless steel pipes are suitable for use in the pulp and paper industry, particularly in processes involving bleaching, chemical recovery, and handling corrosive liquids such as bleach liquor and black liquor.
Power Generation: In power plants, ASTM A790 S31803 pipes are employed in systems for handling cooling water, steam, and other fluids. Their corrosion resistance and high strength make them suitable for applications in both conventional and nuclear power plants.
Mining and Mineral Processing: Duplex stainless steel pipes are used in mining and mineral processing operations for transporting corrosive slurries, acids, and abrasive materials. They offer durability and resistance to wear, erosion, and corrosion, thereby extending the service life of piping systems.
Construction and Infrastructure: Duplex stainless steel pipes are increasingly being used in architectural and structural applications where corrosion resistance and aesthetic appeal are desired. They are employed in bridges, tunnels, wastewater treatment plants, and other infrastructure projects.