ASTM A790 Duplex Stainless Steel Pipe Seamless Welded For Oil Gas Marine Applications
ASTM A790 duplex stainless steel pipe is manufactured in accordance with the American standard for seamless and welded ferritic-austenitic duplex stainless steel pipe. This specification covers pipe intended for general corrosive service, with particular emphasis on applications requiring high strength and excellent resistance to pitting, crevice corrosion, and stress corrosion cracking.
Our ASTM A790 duplex pipes are available in standard duplex grades (2205), super duplex grades (2507), and lean duplex grades (2304), offering solutions for a wide range of demanding environments.
| Parameter | Details |
|---|---|
| Standard | ASTM A790 / ASME SA790 |
| Grades | 2205 (UNS S31803, S32205), 2507 (UNS S32750), S32760, 2304 (UNS S32304) |
| Size (OD) | 6.0 mm – 610 mm (1/8" – 24") |
| Wall Thickness | Schedule 5S, 10S, 40S, 80S, 160, XXS (0.5 mm – 25.0 mm) |
| Length | 3000 mm, 6000 mm, random lengths 6m – 12m (custom cut available) |
| Pipe Type | Seamless (SMLS) or Welded (ERW / EFW / DSAW) |
| Surface Finish | Mill finish, Pickled, Annealed |
| Type | Description | Size Range | Best For |
|---|---|---|---|
| Seamless (SMLS) | Extruded from solid billet, no weld seam | Up to 610 mm OD | High pressure, sour service, critical applications |
| Welded (ERW) | Electric resistance welded | Up to 610 mm OD | General corrosive service, lower cost |
| Welded (EFW/DSAW) | Fusion welded with filler | Large diameters | Large diameter, high volume applications |
| Element | 2205 (S31803) | 2205 (S32205) | 2507 (S32750) | 2304 (S32304) |
|---|---|---|---|---|
| Carbon (C) ≤ | 0.030 | 0.030 | 0.030 | 0.030 |
| Silicon (Si) ≤ | 1.00 | 1.00 | 0.80 | 1.00 |
| Manganese (Mn) ≤ | 2.00 | 2.00 | 1.20 | 2.50 |
| Phosphorus (P) ≤ | 0.030 | 0.030 | 0.035 | 0.035 |
| Sulfur (S) ≤ | 0.020 | 0.020 | 0.020 | 0.020 |
| Chromium (Cr) | 21.0 – 23.0 | 22.0 – 23.0 | 24.0 – 26.0 | 21.5 – 24.5 |
| Nickel (Ni) | 4.5 – 6.5 | 4.5 – 6.5 | 6.0 – 8.0 | 3.0 – 5.5 |
| Molybdenum (Mo) | 2.5 – 3.5 | 3.0 – 3.5 | 3.0 – 5.0 | 0.05 – 0.60 |
| Nitrogen (N) | 0.08 – 0.20 | 0.14 – 0.20 | 0.24 – 0.32 | 0.05 – 0.20 |
| Grade | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) |
|---|---|---|---|---|
| 2205 (S31803) | ≥ 620 | ≥ 450 | ≥ 25 | ≤ 290 |
| 2205 (S32205) | ≥ 620 | ≥ 450 | ≥ 25 | ≤ 290 |
| 2507 (S32750) | ≥ 730 | ≥ 550 | ≥ 20 | ≤ 310 |
| 2304 (S32304) | ≥ 600 | ≥ 400 | ≥ 25 | ≤ 290 |
Note: The values above are minimum requirements per ASTM A790. Please refer to the mill test certificate for actual data.
- High Strength – Yield strength approximately twice that of austenitic grades
- Excellent Pitting Resistance – PREN values ranging from 25 to 41+
- Stress Corrosion Cracking Resistance – Resists chloride SCC
- Good Weldability – Suitable for welding with proper procedures
- Cost Efficiency – Allows for thinner wall sections than austenitic grades
- Full Traceability – Mill test certificates available per EN 10204 3.1/3.2
| Grade | PREN | Pitting Resistance |
|---|---|---|
| 2304 (Lean Duplex) | 24 – 26 | Good |
| 2205 (Standard Duplex) | 33 – 35 | Excellent |
| 2507 (Super Duplex) | 41 – 45 | Superior |
PREN = %Cr + 3.3(%Mo) + 16(%N). Higher value indicates better pitting resistance.
| Grade | Typical Applications |
|---|---|
| 2304 (Lean Duplex) | Cost effective alternative to 316L, fresh water, food processing, structural |
| 2205 (Standard Duplex) | Oil and gas flow lines, chemical processing, marine, heat exchangers, desalination |
| 2507 (Super Duplex) | Deepwater subsea, seawater cooling, sour service (H₂S), FGD systems, offshore |
Need duplex pipe to ASTM A790 specifications? We are ready to supply.
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