Duplex2205 Pipe , ASTM A790 UNS S31803 Duplex Steel Welded Pipe For Water Treatment
Duplex2205 Pipe , ASTM A790 UNS S31803 Duplex Steel Welded Pipe For Water Treatment
UNS S31803 is the most widely used 22% Cr duplex stainless steel grade covered under ASTM A790. It has a balanced dual-phase microstructure consisting of approximately 50% ferrite and 50% austenite. ASTM A790 UNS S31803 duplex stainless steel welded pipe refers to pipe manufactured by longitudinal welding of UNS S31803 duplex stainless steel strip/plate, complying fully with ASTM A790 requirements for chemical composition, mechanical performance, corrosion resistance, inspection and testing. Welded duplex stainless steel pipe offers cost advantages over seamless types for large diameters and long lengths while retaining excellent duplex material properties. YUHONG GROUP has manufactured ASTM A790/ASME SA790 UNS S31803/S32205 duplex stainless steel seamless/welded pipea for more than 35 years. Our pipes are widely used in water treatment system, seawater desalination, chemical and petrochemical industry, oil and gas plant, and so on.
Chemical Composition(%):
| Element | C | Mn | P | S | Si | Cr | Ni | Mo | N |
| UNS S31803 | ≤0.030 | ≤2.00 | ≤0.030 | ≤0.020 | ≤1.00 | 21.0–23.0 | 4.5–6.5 | 2.5–3.5 | 0.08–0.20 |
Mechanical Properties:
| Tensile Strength, Rm | ≥ 620 MPa |
| Yield Strength, Rp0.2 | ≥ 450 MPa |
| Elongation (A, 50mm gauge) | ≥ 25% |
Surface Finishes:
Pickled & Annealed (Most common)
Bright Annealed (BA)
Mechanically Polished
Key Features of ASTM A790 UNS S31803 Duplex Welded Pipe:
High yield strength
Excellent resistance to chloride stress corrosion cracking
Superior pitting and crevice corrosion resistance in seawater and chloride environments
Good erosion-corrosion resistance.
Good weldability
Lower thermal expansion and higher thermal conductivity than austenitic grades.
Cost-effective
Main Applications:
Offshore oil and gas: flowlines, risers, subsea pipelines, manifolds
Chemical and petrochemical processing: reactors, columns, piping, heat exchangers
Seawater desalination and seawater cooling systems
Pulp and paper industry: digesters, bleach plants, liquor systems
Flue gas desulfurization (FGD) and scrubbers
Oil refinery and sour service piping
Pressure vessels, storage tanks, and process piping
Marine and shipbuilding: seawater piping, ballast systems
Power generation: condenser tubes, feedwater heaters
Food, pharmaceutical, and biotechnology
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