ASTM A790 Pipe
SSM supplies ASTM A790 seamless and welded duplex stainless steel pipes
A790 Seamless and Welded ferritic/austenitic (duplex) Stainless Steel Pipes
SSM provides ASTM A790 seamless and welded duplex stainless steel pipes. These pipes are renowned for their high strength, good ductility, and excellent corrosion resistance, particularly in environments with chloride ions. They are widely utilized in chemical processing, oil and gas, petrochemical, and marine applications where superior resistance to stress corrosion cracking and pitting is essential.
A790 seamless and welded stainless steel supplier, SSM provides product parameters as shown in the following table:
| Items | Parameters |
| OD | NPS 1/8″ – NPS 30″ |
| WT | Common wall thickness specifications include SCH 10, SCH 20, SCH 40, SCH 80, SCH 160, XXS (extra strong wall), etc. |
| Length | 20 feet (6 meters) or 40 feet (12 meters), according to customer requirements. |
| Grade | Common Grades: S31803, S32205, S32750, S32760 |
| Standards | ASTM A790 / ASME B36.19 M |
| End Finish | Plain ends / Beveled Ends / Threaded Ends |
| Surface Condition | Pickled / Passivated |
Chemical Composition & Mechanical Properties
ASTM A790 pipes, whether seamless or welded, made from these grades, are suitable for demanding applications in chemical processing, oil and gas, petrochemical, and marine industries where high strength, excellent corrosion resistance, and good toughness are required.
| Element | UNS S31803 (Duplex 2205) | UNS S32205 (Duplex 2205) | UNS S32750 (Super Duplex 2507) | UNS S32760 (Super Duplex) |
| Carbon (C) | ≤ 0.03% | ≤ 0.03% | ≤ 0.03% | ≤ 0.03% |
| Manganese (Mn) | ≤ 2.00% | ≤ 2.00% | ≤ 1.20% | ≤ 1.00% |
| Silicon (Si) | ≤ 1.00% | ≤ 1.00% | ≤ 0.80% | ≤ 0.80% |
| Phosphorus (P) | ≤ 0.030% | ≤ 0.030% | ≤ 0.035% | ≤ 0.03% |
| Sulfur (S) | ≤ 0.020% | ≤ 0.020% | ≤ 0.020% | ≤ 0.01% |
| Chromium (Cr) | 21.0-23.0% | 22.0-23.0% | 24.0-26.0% | 24.0-26.0% |
| Nickel (Ni) | 4.5-6.5% | 4.5-6.5% | 6.0-8.0% | 6.0-8.0% |
| Molybdenum (Mo) | 2.5-3.5% | 3.0-3.5% | 3.0-5.0% | 3.0-4.0% |
| Nitrogen (N) | 0.08-0.20% | 0.14-0.20% | 0.24-0.32% | 0.24-0.32% |
| Copper (Cu) | – | – | ≤ 0.50% | 0.50-1.00% |
| Tungsten (W) | – | – | – | 0.50-1.00% |
The mechanical properties of each grade also differ:
| Property | UNS S31803 (Duplex 2205) | UNS S32205 (Duplex 2205) | UNS S32750 (Super Duplex 2507) | UNS S32760 (Super Duplex) |
| Yield Strength (0.2% offset), min | 450 MPa (65 ksi) | 450 MPa (65 ksi) | 550 MPa (80 ksi) | 550 MPa (80 ksi) |
| Tensile Strength, min | 620 MPa (90 ksi) | 620 MPa (90 ksi) | 800 MPa (116 ksi) | 750 MPa (109 ksi) |
| Elongation, min (%) | 25 | 25 | 15 | 25 |
| Hardness, max (HRB) | 290 | 290 | 310 | 310 |
| Impact Toughness, min (J at -50°C) | 27 | 27 | 50 | 50 |
Manufacturing & Tolerance Requirements
Manufacturing Methods
Seamless pipes are manufactured using hot extrusion, cold working, and heat treatment. Plates or strips are formed into cylindrical shapes using processes like roll forming, welding, and post-weld heat treatment to produce welded pipes.
Tolerance Requirements
| Permitted Variations in Wall Thickness | ||
| Tolerance,%from Nominal | ||
| NPS Designator | Over | Unders |
| 1/8 %to 2%incl, all t/D ratios | 20 | 12.5 |
| 3 to 18 incl., t/D up to 5% incl. | 22.5 | 12.5 |
| 3 to 18 incl., t/D>5% incl. | 15 | 12.5 |
| 20 and larger,welded,all t/D ratios | 17.5 | 12.5 |
| 20 and larger,seamless, t/D up to 5%incl. | 22.5 | 12.5 |
| 20 and larger,seamless, t/D>5% | 15 | 12.5 |
where: t =Nominal Wall ThicknessD =Ordered Outside Diameter
Lengths
The length of the pipes shall be as specified in the purchase order. Common lengths are single random (17-24 feet) and double random (38-40 feet), but custom lengths can also be ordered.
Pipes may also be supplied in cut lengths with a permissible variation of +1/8 inch (3.2 mm) and -0.
Advantages and Disadvantages of ASTM A790
Advantages:
Duplex and super duplex stainless steels have high yield strength and excellent resistance to chloride stress corrosion cracking, pitting, and crevice corrosion. They also have good toughness and ductility at both low and high temperatures, making them suitable for various applications. The combination of high strength and corrosion resistance can save on materials and extend service life, reducing overall costs.
Disadvantages:
Although these stainless steels offer long-term cost-effectiveness, their initial cost may be higher than that of standard grades. Additionally, they can become prone to embrittlement at temperatures above 300°C due to the formation of intermetallic phases. Furthermore, the production process for duplex and super duplex stainless steels can be more complex and expensive compared to that of standard austenitic or ferritic stainless steel.
Applications of ASTM A790 Pipes
- Oil and Gas Industry
- Chemical Processing Industry
- Petrochemical Industry
- Marine Industry
- Power Generation
- Desalination Plants
- Pharmaceutical Industry
Comparison of Duplex 2205 Pipes and Super Duplex 2507 Pipes
This table summarizes the key differences between Duplex 2205 and Super Duplex 2507 in terms of composition, mechanical properties, corrosion resistance, applications, and cost.
| Feature/Property | Duplex 2205 | Super Duplex 2507 |
| Composition | 22% Cr, 5-6% Ni, 3% Mo, 0.2% N | 24-26% Cr, 6-8% Ni, 3-4% Mo, 0.24-0.32% N |
| Mechanical Properties | Yield Strength: 450-620 MPa | Yield Strength: > 550 MPa |
| Good strength and ductility | Higher strength and corrosion resistance | |
| Corrosion Resistance | Good resistance to general corrosion | Superior resistance to chloride-induced stress corrosion cracking and pitting |
| Moderate resistance in highly corrosive environments | Excellent in aggressive environments like seawater | |
| Applications | Petrochemical, oil refineries, industrial | Offshore platforms, marine environments, chemical processing |
| Structural components, heat exchangers | Seawater handling systems, desalination | |
| Cost | Lower cost compared to Super Duplex 2507 | Higher cost due to higher alloy content |
Related Products
