Duplex Stainless Steel S31803 Seamless Pipes & Tubes
Duplex S31803 is the earlier designation that overlaps with S32205. S31803 has a slightly wider composition range and may have a lower minimum PREN than S32205. Many existing specifications still reference S31803, though S32205 is now the preferred designation for new projects.
Size Range
1/4" NPS to 10" NPS (6.35mm to 273.1mm OD)
Wall Thickness
SCH 5S to SCH 160
Standards
4 specs
Chemical Composition (% by weight)
| C | Mn | Si | Cr | Ni | Mo | N | P | S |
|---|---|---|---|---|---|---|---|---|
| 0.030 max | 2.00 max | 1.00 max | 21.0-23.0 | 4.5-6.5 | 2.5-3.5 | 0.08-0.20 | 0.030 max | 0.020 max |
Mechanical Properties (Minimum at Room Temperature)
| Tensile Strength | Yield Strength | Elongation | Hardness |
|---|---|---|---|
| 620 MPa min | 450 MPa min | 25% min | 293 HBW max |
Physical Properties - Duplex S31803
| Density | Melting Range | Thermal Conductivity | Electrical Resistivity | Specific Heat | Coeff. of Thermal Expansion |
|---|---|---|---|---|---|
| 7.82 g/cm3 | 1350-1400 C | 19 W/m-K | 850 nOhm-m | 480 J/kg-K | 13.0 um/m-C |
Corrosion Resistance - Duplex S31803
| Property | Value |
|---|---|
| Pitting Resistance (PREN) | ~33 |
| Max Service Temp (Oxidizing) | 315 C |
| Intergranular Corrosion | Highly resistant |
| Stress Corrosion Cracking | Excellent resistance |
| General Corrosion Rate | <0.02 mm/yr in most environments |
| Seawater Resistance | Excellent up to 20C |
Equivalent International Grades
| ASTM | NORSOK | Trade |
|---|---|---|
| S31803 | MDS D45 | 2205/S31803 |
Duplex S31803 vs Comparable Grades
| Grade | UNS | Tensile | Yield | PREN | Max Temp |
|---|---|---|---|---|---|
| Duplex 2205Duplex Stainless Steel | S32205 | 655 MPa min | 450 MPa min | ~35 | 315 C (to avoid 475C embrittlement) |
| SS 316 / 316LAustenitic Stainless Steel | S31600 | 515 / 485 MPa min | 205 / 170 MPa min | ~24 | 870 C |
| Super Duplex 2507Super Duplex Stainless Steel | S32750 | 795 MPa min | 550 MPa min | >42 (typ. 42-44) | 315 C |
Applicable Standards
Applications
Key Advantages of Duplex S31803
Duplex S31803 Applications by Region
Middle East (UAE, Saudi Arabia, Qatar, Oman, Kuwait)
Legacy specifications in older plants still reference S31803. Used interchangeably with S32205 in UAE, Saudi Arabia, and Qatar.
Europe (Germany, UK, Norway, Netherlands, Italy)
Common in existing offshore installations and chemical plants across Norway, UK, and Netherlands.
United States
Used where older specifications reference S31803; new projects typically specify S32205.
Frequently Asked Questions about Duplex S31803 Seamless Pipes
Quick Specifications
1/4" NPS to 10" NPS (6.35mm to 273.1mm OD)
SCH 5S to SCH 160
Industries Served
Related Grades
Compare With
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Stancor is India's leading manufacturer of Duplex S31803 seamless pipes, exporting to UAE, Saudi Arabia, Qatar, Germany, UK, and USA. Contact our sales team for competitive pricing, fast delivery, and full material certification.