Guides/Comparisons
2205 duplex vs 316 stainless steel
2205-vs-316-stainless-steelDuplex stainless steel 2205 and Stainless steel 316 at a glance
This page compares Duplex stainless steel 2205 and Stainless steel 316 using only values that carry a source, a test condition and an evidence level. Ranges run across temper, heat treatment and product form, measured at room temperature where the source says so.
- Composition: Chromium (2205 22 to 23%; 316 16 to 18%), Nickel (2205 4.5 to 6.5%; 316 10 to 14%), Molybdenum (2205 3 to 3.5%; 316 2 to 3%), Nitrogen (2205 0.14 to 0.2%; 316 up to 0.1%).
- Yield strength: 2205 is higher (2205 at least 450 MPa; 316 193 to 213 MPa), about 3.3 times the midpoint of 316.
- Tensile strength: 2205 is higher (2205 655 to 965 MPa; 316 480 to 620 MPa), about 1.5 times the midpoint of 316.
- Density: 316 is higher (2205 7.8 to 7.82 g/cm³; 316 7.87 to 8.07 g/cm³), a difference of under 10% at the midpoint.
- Young's modulus: the ranges overlap (2205 190 to 200 GPa; 316 190 to 205 GPa).
- Thermal conductivity: the ranges overlap (2205 14 to 15 W/(m·K); 316 13 to 17 W/(m·K)).
- Melting point: the ranges overlap (2205 1,385 to 1,441 °C; 316 1,375 to 1,440 °C).
- Service temperature: 316 is higher (2205 280 to 316 °C; 316 750 to 925 °C), about 2.8 times the midpoint of 2205.
- Thermal expansion: 316 is higher (2205 11 to 13 ppm/K; 316 16.5 to 18.2 ppm/K), about 1.4 times the midpoint of 2205.
"Higher" means the whole range is higher, not just one value. Where a value is a specified minimum, the table says "at least".
Side by side
| Property | Duplex stainless steel 2205 | Stainless steel 316 |
|---|---|---|
| Yield strength | at least 450 MPa | 193 to 213 MPa |
| Tensile strength | 655 to 965 MPa | 480 to 620 MPa |
| Density | 7.8 to 7.82 g/cm³ | 7.87 to 8.07 g/cm³ |
| Young's modulus | 190 to 200 GPa | 190 to 205 GPa |
| Thermal conductivity | 14 to 15 W/(m·K) | 13 to 17 W/(m·K) |
| Melting point | 1,385 to 1,441 °C | 1,375 to 1,440 °C |
| Service temperature | 280 to 316 °C | 750 to 925 °C |
| Thermal expansion | 11 to 13 ppm/K | 16.5 to 18.2 ppm/K |
Composition
| Element | Duplex stainless steel 2205 | Stainless steel 316 |
|---|---|---|
| Iron | balance | balance |
| Chromium | 22 to 23% | 16 to 18% |
| Nickel | 4.5 to 6.5% | 10 to 14% |
| Molybdenum | 3 to 3.5% | 2 to 3% |
| Nitrogen | 0.14 to 0.2% | up to 0.1% |
| Carbon | up to 0.03% | up to 0.08% |
| Manganese | up to 2% | up to 2% |
| Silicon | up to 1% | up to 0.75% |
| Phosphorus | up to 0.03% | up to 0.045% |
| Sulphur | up to 0.02% | up to 0.03% |
Shares are as printed in the sources, by weight.
When to use which
| Material | Best for | Weakest at |
|---|---|---|
| Duplex stainless steel 2205 | Chloride-bearing and sour service where 300-series steels crack, in welded pipe, tube, sheet and plate (ATI, Alleima) | Extended exposure at 343 to 530 C (475 C embrittlement), welds made with straight chromium filler, and sour service above 232 C (ATI, Alleima) |
| Stainless steel 316 | Chloride-bearing and marine-grade service where 304 would pit, in annealed sheet, bar and plate | Crevice and pitting attack in seawater condenser tubes, intergranular attack after heating between 500 and 900 C, and modest strength next to precipitation-hardened grades |
Where each is used
| Material | Use |
|---|---|
| Duplex stainless steel 2205 | Chemical process vessels, piping and heat exchangers |
| Duplex stainless steel 2205 | Oil and gas production tubing, flowlines and heat exchangers in sour service |
| Duplex stainless steel 2205 | Marine propellers, shafts, rudders, pumps and valves |
| Stainless steel 316 | Aerospace structures |
| Stainless steel 316 | Chemical storage, food processing and oil refining equipment |