Guides/Comparisons
2205 vs 2507 duplex stainless steel
2205-vs-2507-duplex-stainless-steelDuplex stainless steel 2205 and Super duplex stainless steel 2507 at a glance
This page compares Duplex stainless steel 2205 and Super duplex stainless steel 2507 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%; 2507 25%), Nickel (2205 4.5 to 6.5%; 2507 7%), Molybdenum (2205 3 to 3.5%; 2507 4%), Nitrogen (2205 0.14 to 0.2%; 2507 0.3%).
- Yield strength: the ranges overlap (2205 at least 450 MPa; 2507 at least 530 MPa).
- Tensile strength: the ranges overlap (2205 655 to 965 MPa; 2507 750 to 1,000 MPa).
- Density: the ranges overlap (2205 7.8 to 7.82 g/cm³; 2507 7.8 g/cm³).
- Young's modulus: the ranges overlap (2205 190 to 200 GPa; 2507 200 GPa).
- Thermal conductivity: the ranges overlap (2205 14 to 15 W/(m·K); 2507 14 W/(m·K)).
- Service temperature: 2205 is higher (2205 280 to 316 °C; 2507 232 °C), about 1.3 times the midpoint of 2507.
- Thermal expansion: 2507 is higher (2205 11 to 13 ppm/K; 2507 13.5 ppm/K), about 1.1 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 | Super duplex stainless steel 2507 |
|---|---|---|
| Yield strength | at least 450 MPa | at least 530 MPa |
| Tensile strength | 655 to 965 MPa | 750 to 1,000 MPa |
| Density | 7.8 to 7.82 g/cm³ | 7.8 g/cm³ |
| Young's modulus | 190 to 200 GPa | 200 GPa |
| Thermal conductivity | 14 to 15 W/(m·K) | 14 W/(m·K) |
| Melting point | 1,385 to 1,441 °C | no data |
| Service temperature | 280 to 316 °C | 232 °C |
| Thermal expansion | 11 to 13 ppm/K | 13.5 ppm/K |
Composition
| Element | Duplex stainless steel 2205 | Super duplex stainless steel 2507 |
|---|---|---|
| Iron | balance | balance |
| Chromium | 22 to 23% | 25% |
| Nickel | 4.5 to 6.5% | 7% |
| Molybdenum | 3 to 3.5% | 4% |
| Nitrogen | 0.14 to 0.2% | 0.3% |
| Carbon | up to 0.03% | up to 0.03% |
| Manganese | up to 2% | up to 1.2% |
| Silicon | up to 1% | up to 0.8% |
| Phosphorus | up to 0.03% | up to 0.035% |
| Sulphur | up to 0.02% | up to 0.015% |
| Copper | not listed | up to 0.5% |
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) |
| Super duplex stainless steel 2507 | Chloride-bearing seawater, subsea and sour oil and gas service that needs high strength and pitting resistance, in solution-annealed tube, bar and forgings | Prolonged exposure above 250 °C, which lowers impact strength, and hydrogen-induced cracking in cathodically protected subsea steel |
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 |
| Super duplex stainless steel 2507 | Subsea umbilicals and offshore oil and gas tubing |
| Super duplex stainless steel 2507 | Seawater cooling tubing and desalination pressure vessels |
| Super duplex stainless steel 2507 | Propeller shafts and high-load parts in seawater |
| Super duplex stainless steel 2507 | Forged flanges and fittings to ASTM A182 Grade F53 |