Seamless Duplex Steel S31803 |UNS S31803|1.4462 Tube
Our S31803 duplex tubes offer a strategic combination of high yield strength—nearly double that of conventional 316L—and outstanding resistance to chloride-induced stress corrosion cracking (SCC) and pitting. These properties make them indispensable for heat exchangers, chemical processing, and marine engineering. Through advanced cold-drawing and precision solution annealing, Tengqi ensures every tube maintains optimal phase balance and a high-integrity surface finish for long-term industrial reliability.
"Our S31803 tubes are often dual-certified to meet S32205 standards, ensuring higher nitrogen and chromium content for even better corrosion resistance."
Seamless Duplex Steel S31803 Tube (S31803 / UNS S31803 / W.Nr. 1.4462) is the standard 22% Cr duplex grade with roughly twice the yield strength of 304/316. Manufactured by Tengqi in Fujian, China, every heat is fully traceable, hydro-tested and available with third-party inspection (SGS / BV / TUV) on request.
Product Specifications
- ASTM A789 / ASME SA789 — Seamless & Welded
- ASTM A790 / ASME SA790 — Seamless Pipe
- ASTM A1016 / A1016M — General Requirements
- Finishing: solution annealed, pickled & polished; bright annealed available on request
Size Range
| Outside Diameter (OD) | Wall Thickness | Length |
|---|---|---|
| 6.35 mm – 257 mm (1/4"– 10.1") | 0.5 mm – 12.7 mm | ≤ 22 m |
Chemical Composition
S31803 (UNS S31803) — Composition %
| UNS | C | Mn | P | S | Si | Cr | Ni | Mo | N |
|---|---|---|---|---|---|---|---|---|---|
| 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
| Property | Value |
|---|---|
| Delivery Condition | Solution annealed, pickled & polished |
| Tensile Strength | ≥ 620 MPa |
| Yield Strength (0.2% offset) | ≥ 450 MPa |
| Elongation in 2 in. / 50 mm | ≥ 25% |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.8 g/cm3 |
| Thermal Conductivity | 17.0 W/m·K |
| Specific Heat Capacity | 480 J/kg·K |
| Elastic Modulus | 200 GPa |
| Magnetic Properties | Magnetic |
| PREN (Pitting Resistance Equivalent) | 32.0-35.0 |
Industry Applications
Related Products
Related Seamless Pipes & Tubes
Explore more grades and sizes from XTD Special Steel — related seamless pipe and tube products:
- Seamless Duplex Steel S31803 Pipe
- Seamless Duplex Steel S32205 Tube
- Seamless Duplex Steel S31500 Tube
- Seamless Duplex Steel S32205 Pipe
- Seamless Duplex Steel S31500 Pipe
Browse the complete ranges: All Duplex Steel Tubes | Explore Duplex Steel Pipes | Seamless Stainless Steel Tubes Catalog
CONTACT US
Lidun Industrial Park, Lidun Town, Zhouning County, Ningde City, Fujian Province，355400，China
+86-577-88877003
+86-577-88877015
+86-577-88877019
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