ASTM A790 UNS S31803 Seamless Pipe | Duplex Stainless Steel
ASTM A790 UNS S31803 seamless pipes are manufactured for high strength and excellent corrosion resistance in oil & gas, chemical processing and offshore applications. Fully compliant with ASTM A790/A790M, supplied with EN 10204 3.1 certification.
We are the manufacturer ,Supplier & Exporter of Duplex UNS S31803 Pipe, UNS S31803 Duplex stainless steel Seamless Pipe.
What is ASTM A790 S31803？
ASTM A790 S31803 is a specification for seamless and welded ferritic/austenitic stainless steel pipes. This grade of stainless steel, also known as duplex stainless steel, offers excellent corrosion resistance, high strength, and good weldability, making it suitable for a wide range of applications in various industries.
A790 S31803 pipes are made from a duplex stainless steel alloy, which consists of a balanced mixture of ferritic and austenitic phases. This unique microstructure provides the pipes with a combination of high strength and corrosion resistance.
UNS S31803, 1.4462 duplex stainless steel is designed to combine improved resistance to stress corrosion cracking, pitting, crevice corrosion and high strength when compared with other stainless alloys
ASME SA789/SA789M ( ASTMA789/A789M )
General use standard specification for seamless and Welded Ferritic / austenitic stainless steel tube
The Pipe Sizes & Schedules availability for ASTM A790 S31803 Pipe
Pipe Sizes:
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Seamless Pipe: ½” – 24”
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Welded Pipe: 6” – 60”
Schedules:
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SCH 10, SCH 40, SCH 80, SCH 160, XXS
Duplex stainless steels are extremely corrosion resistant, work hardenable alloys. Their microstructures consist of a mixture of austenite and ferrite phases. As a result, duplex stainless steels display properties characteristic of both austenitic and ferritic stainless steels. This combination of properties can mean some compromise when compared with pure austenitic and pure ferritic grades.
Duplex stainless steels are in most cases, tougher than ferritic stainless steels. Strengths of duplex stainless steels can in some cases be double that for austenitic stainless steels.
The duplex stainless steels are considered resistant to stress corrosion cracking, they are not as resistant to this form of attack as ferritic stainless steels. However, the corrosion resistance of the least resistant duplex stainless steels is greater than that for the most commonly used grades of stainless steels, i.e. 304 and 316.
Duplex stainless steels are also magnetic, a property that can be used to easily differentiate them from common austenitic grades of stainless.
Property data given in this document is typical for flat rolled products covered by ASTM A240/A240M. ASTM, EN or other standards may cover products sold. It is reasonable to expect specifications in these standards to be similar but not necessarily identical to those given in this datasheet.
SEAMLESS PIPES EQUIVALENT GRADE
| Standard | Equivalent Grade |
|---|---|
| ASTM | A790 UNS S31803 |
| EN | 1.4462 (X2CrNiMoN22-5-3) |
| JIS | SUS 329J3L |
| DIN | W.Nr 1.4462 |
| STANDARD | WERKSTOFF NR. | UNS |
| Duplex UNS S31803 | 1.4462 | S31803 |
| Duplex UNS S32205 | 1.4462 | S32205 |
DUPLEX STEEL A790 UNS S31803 PIPE CHEMICAL COMPOSITION
| 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 |
DUPLEX STEEL A790 UNS S31803 PIPE MECHANICAL PROPERTIES
| 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. |
Why A790 S31803 pipes?
Advantages of ASTM A790 S31803 Pipes: The allure of ASTM A790 S31803 pipes lies not only in their robust construction but also in their myriad advantages. Foremost among these is their unparalleled corrosion resistance, which surpasses that of conventional austenitic and ferritic stainless steels. This resistance extends to various forms of corrosion, including pitting, crevice corrosion, and stress corrosion cracking, ensuring longevity even in the harshest environments. Furthermore, the high strength of S31803 pipes enables them to withstand elevated temperatures and pressures, making them ideal candidates for high-stress applications. Beyond their intrinsic properties, ASTM A790 S31803 pipes offer cost-efficiency through reduced maintenance requirements and prolonged service life, delivering substantial savings over their operational lifespan.
Testing Requirements for ASTM A790 UNS S31803 Pipes
Tensile Test – Ensures minimum strength & elongation
Hardness Test – Confirms material is within specified limits
Impact Test (Charpy V-Notch) – Evaluates toughness at low temperatures
Intergranular Corrosion Test (IGC Test) – Ensures resistance to grain boundary corrosion
Hydrostatic Test – Verifies pipe pressure resistance
Non-Destructive Testing (NDT) – Includes ultrasonic or eddy current testing
UNS S31803 Seamless Pipes vs Welded Pipe
UNS S31803 seamless pipes and welded pipes differ mainly in manufacturing process, mechanical performance and application suitability. Understanding these differences helps engineers and buyers select the right pipe type for specific service conditions.
Seamless pipes are manufactured from solid billets through hot extrusion or piercing, resulting in a uniform structure without weld seams. UNS S31803 duplex stainless steel seamless pipes offer higher pressure resistance, better mechanical strength and improved reliability in critical applications. They are widely used in oil & gas, chemical processing, offshore platforms and high-temperature or high-pressure environments.
Welded pipes, on the other hand, are produced by forming stainless steel plates or strips and welding the longitudinal seam. While welded pipes are generally more cost-effective and suitable for low-pressure or non-critical services, the weld seam may represent a potential weak point under extreme conditions such as high pressure, cyclic loading or corrosive environments.
For demanding applications requiring superior strength, corrosion resistance and long-term performance, UNS S31803 seamless pipes are the preferred choice. They comply with ASTM A790/A790M requirements and are commonly supplied with EN 10204 3.1 certification to ensure quality and traceability.
| Item | Seamless Pipe | Welded Pipe |
|---|---|---|
| Manufacturing | From solid billet | From plate/strip |
| Weld seam | None | Present |
| Pressure resistance | Higher | Lower |
| Typical applications | Oil & gas, offshore | Low-pressure service |
| Cost | Higher | Lower |
We are your trusted partner in procuring premium-grade ASTM A790 S31803 pipes tailored to your unique requirements. Contact us today to unlock the unparalleled performance and durability of S31803 pipes for your next project.
Download ASTM A790 UNS S31803 Duplex stainless steel pipe Specification
Download ASTM A790 Pipe specification
Download A 790A 790M standard specifiction
ASTM A790 UNS S31803 seamless pipes are selected for applications requiring stable mechanical strength, corrosion resistance and reliable performance in low-temperature service. The seamless manufacturing process eliminates weld seams, enhancing pressure integrity and long-term reliability.
As a standard duplex stainless steel grade, UNS S31803 seamless pipes provide a balanced solution for industrial piping systems where performance, availability and cost efficiency are key considerations.
