Duplex stainless steels are extremely corrosion resistant, work hardenable alloys. Their microstructures consist of a mixture of austenite and ferrite phases. As a result, duplex stainless steels display properties characteristic of both austenitic and ferritic stainless steels. This combination of properties can mean some compromise when compared with pure austenitic and pure ferritic grades.
Chemical Composition
| Element | Content (%) |
Iron, Fe | 63.75-71.92 |
Chromium, Cr | 21.0-23.0 |
Nickel, Ni | 4.50-6.50 |
Molybdenum, Mo | 2.50-3.50 |
Manganese, Mn | 2.0 |
Silicon, Si | 1.0 |
Nitrogen, N | 0.080-0.20 |
Carbon, C | 0.030 |
Phosphorous, P | 0.030 |
Sulfur, S | 0.020 |
| Properties | Metric | Imperial |
Density | 7.82 g/cm³ | 0.283 lb/in³ |
| Properties | Metric | Imperial |
Tensile strength at break | 621 MPa | 90000 psi |
Yield strength (@strain 0.200 %) | 448 MPa | 65000 psi |
Elongation at break (in 50 mm) | 25.0 % | 25.0 % |
Hardness, Brinell | 293 | 293 |
Hardness, Rockwell c | 31.0 | 31.0 |
| Properties | Metric | Imperial |
Thermal expansion co-efficient (@20-100°C/68-212°F) | 13.7 µm/m°C | 7.60 µin/in°F |
