Sandvik 21-6-9 is an austenitic grade with a high level of Mn, a low level of Ni and the addition of N. The grade is characterized by:
- High mechanical strength in the hard condition
- Very good impact toughness in temperatures down to -230°C (-382°F)
- Very good high temperature oxidation resistance
Standards
-
UNS: S21900
Product standards
- AMS 5561
Customer specifications on request.
Chemical composition (nominal)
| C | Si | Mn | P | S | Cr | Ni | Mo | Cu | N |
|---|---|---|---|---|---|---|---|---|---|
| ≤0.040 | ≤1.00 | 8.00 - 10.00 | ≤0.030 | ≤0.030 | 19.00 - 21.50 | 5.50 - 7.50 | ≤0.75 | ≤0.75 | 0.15 - 0.40 |
Applications
Sandvik 21-6-9 seamless tube is used for components in the aircraft industry.
Forms of supply
Sandvik 21-6-9 seamless stainless steel tubes are supplied in the bright annealed condition or cold-worked.
| Outside diameter, mm (in.) | Wall thickness, mm (in.) |
|---|---|
| 2 - 65 (0.079 - 2.56) | 0.3 - 25 (0.012 - 1.0) |
| Outside diameter, mm (in.) | Wall thickness, % |
|---|---|
| +/- 0.05, or 0.1 (+/- 0.002, or 0.004) | +/- 10 |
| For special tolerance requirements, please contact Sandvik. | |
Mechanical properties
| Proof strength, Rp0.2 | Tensile strength, Rm | Elongation, A2" |
|---|---|---|
| MPa (ksi) | MPa (ksi) | % |
| ≥330 (48) | ≥655 (95) |
≥35 |
| Proof strength, Rp0.2 | Tensile strength, Rm | Elongation, A2" |
|---|---|---|
| MPa (ksi) | MPa (ksi) | % |
| ≥827 (120) | ≥979 (142) |
≥20 |
Physical properties
Density
7.81 g/cm3 (0.282 lb/in3)
| Temperature, °C | J/(kg °C) | Temperature, °F | Btu/(lb °F) |
|---|---|---|---|
| 0 | 480 | 32 | 0.12 |
| 100 | 480 | 212 | 0.12 |
| Temperature, °C | MPa | Temperature, °F | ksi |
|---|---|---|---|
| 20 | 200 | 68 | 28.9 |
Poisson's ratio
0.285