GNEE is a professional exporter of duplex stainless steel pipes, supplying products to more than 60 countries including the United States, Germany, the United Arab Emirates, Brazil, and South Korea. We provide professional technical support and guarantee on-time delivery.
GNEE supplies ASTM A312 SS 2205 duplex stainless steel seamless pipes in compliance with ASME SA312 and NACE MR0175 standards. The outer diameter ranges from 12.7 mm to 610 mm, with wall thickness from SCH 5S to SCH 160. Standard lengths are 6 m and 12 m, with customization available according to customer requirements. Delivery is primarily in the solution annealed condition.
ASTM A312 SS 2205 stainless steel pipes feature a balanced duplex microstructure, with chemical composition of Cr 22.0–23.0%, Ni 5.0–7.0%, Mo 3.0–3.5%, and N 0.14–0.20%. With a PREN value ≥35, they offer excellent resistance to pitting, crevice corrosion, and chloride-induced stress corrosion cracking (SCC), making them particularly suitable for chloride-containing environments. The room temperature yield strength (≥450 MPa) is more than twice that of 316L, significantly reducing equipment weight and required wall thickness.
These pipes maintain high strength and structural stability under high pressure and harsh operating conditions. Each pipe undergoes 100% hydrostatic testing, ultrasonic testing (UT), eddy current testing, and PMI inspection. Dimensional tolerances are strictly controlled within OD ±0.1 mm and WT ±0.08 mm.
We provide EN 10204 3.1 MTC, TUV, and SGS inspection reports, and maintain a stable long-term supply capacity, serving industries such as offshore, oil and gas, chemical processing, seawater desalination, and marine engineering projects.
ASTM A312 SS 2205 SMLS Pipes Specification
| Item | Description |
|---|---|
| Grade | Duplex 2205 |
| UNS Designation | S31803 / S32205 (Dual Certified) |
| Common Name | Duplex 2205, Alloy 2205 |
| Standards | ASTM A790 / A312, ASME SA790 / SA312 |
| Structure | Ferritic-Austenitic (approx. 50/50 ratio) |
| Manufacturing | Hot Rolled / Cold Drawn Seamless (SMLS) |
| Size Range (NPS) | 1/2" to 12" (Seamless) |
| Wall Thickness | Schedule 10S, 40S, 80S, 160, XXS |
| OD Tolerance | According to ASTM A999 |
| Wall Tolerance | ±12.5% (Standard) |
| Length | Single Random (5–7m), Double Random (10–12m), Fixed Length |
Chemical Composition (Mass Fraction, %)
| Element | Symbol | S31803 (%) | S32205 (%) |
| Carbon | C |
≤0.030 |
≤0.030 |
| Manganese | Mn |
≤2.00 |
≤2.00 |
| Silicon | Si |
≤1.00 |
≤1.00 |
| Phosphorus | P |
≤0.030 |
≤0.030 |
| Sulfur | S |
≤0.020 |
≤0.020 |
| Chromium | Cr | 21.0 – 23.0 | 22.0 – 23.0 |
| Nickel | Ni | 4.5 – 6.5 | 4.5 – 6.5 |
| Molybdenum | Mo | 2.5 – 3.5 | 3.0 – 3.5 |
| Nitrogen | N | 0.08 – 0.20 | 0.14 – 0.20 |
Mechanical Properties (Min. Values at Room Temp.)
| Property | Metric Value | Imperial Value |
| Tensile Strength (Rm) |
≥655 MPa |
≥95 ksi |
| Yield Strength (Rp0.2) |
≥450 MPa |
≥65 ksi |
| Elongation (Ain 2 in.) |
≥25 % |
≥25 % |
| Hardness (Rockwell C) |
≤31 HRC |
≤31 HRC |
| Hardness (Brinell) |
≤293 HBW |
≤293 HBW |
Physical Properties
| Property | Value (at 20°C) |
| Density | 7.8 kg/dm ³ |
| Modulus of Elasticity | 190 GPa |
| Thermal Conductivity | 19.0 W/(m·K) |
| Specific Heat | 450 J/(kg·K) |
| Electrical Resistivity | 0.85 Ω⋅mm2/m |
| PREN Value |
≥35 |
What are the differences between ASTM A312 and ASTM A790 standards for 2205 stainless steel tubing?
ASTM A312 is a general standard for seamless, straight-seam welded, and heavily cold-worked austenitic stainless steel tubing.
ASTM A790 is a specific standard for seamless and welded ferritic/austenitic (duplex) stainless steel tubing.
While many buyers use the A312 standard out of habit, ASTM A790 is the correct technical standard for 2205 stainless steel tubing. Most reputable manufacturers will "dual-certify" their tubing to comply with both standards.
HS Code Reference Table: ASTM A790 2205 SMLS Pipes
| Product Category | Manufacturing Method | International HS Code (6-Digit) | Example National Code (e.g., China) | Description |
| Stainless Steel Seamless Pipe | Cold-drawn / Cold-rolled | 7304.41 | 7304.4190.00 | Tubes, pipes and hollow profiles, seamless, of stainless steel, cold-finished. |
| Stainless Steel Seamless Pipe | Hot-rolled / Hot-finished | 7304.49 | 7304.4990.00 | Tubes, pipes and hollow profiles, seamless, of stainless steel, other (hot-finished). |
GNEE supplies 2205 stainless steel pipes that have undergone solution annealing and water quenching to ensure they are free of σ phase. The minimum PREN value is 35. Dual certifications are available: S31803/S32205. Third-party inspection is welcome.
Delivery Lead Time
Stock Items: Standard sizes (e.g., NPS 1/2" - 8", Sch 10S/40S).
Lead Time: 1 - 2 weeks (mainly for surface cleaning, finishing, packaging, and inspection).
New Production:
Scope: Non-standard wall thickness, extra-large diameter, or special length (e.g., 12-meter standard length).
Lead Time: 6 - 10 weeks.
Packaging:
End Protection: Add plastic caps to both ends to prevent damage to the chamfer and internal contamination.
Individual Protection: Cover each tube with a plastic bag or woven mesh (to prevent tube-to-tube abrasion during transport).
Outer Packaging: Preferred: Fumigation-free plywood cases.
