Alloys 254 / 254 SMO / 6 Mo is an austenitic stainless steel with a high molybdenum content. Coupled with Nickel and Copper this gives the alloy a good resistance to pitting and crevice corrosion, especially in environments containing halide ions, e.g. chloride, bromide and fluoride solutions.
254 SMO (UNS S31254) may offer a cost effective solution to Nickel and Titanium alloys in these environments.
| Alloy | Common Name | Related Specifications | Tensile Strength | Proof Stress | Elongation | ||
|---|---|---|---|---|---|---|---|
| British | European | United States | |||||
| Alloy 254 | 254SMO | 1.4547 |
ASTM A479/A473, /A240 S31254 F44 |
655 [95] |
305 [44.2] |
35 | |
| Elements | C | Cr | Fe | Mo | Mn | N | Ni | Nb | P | S | Si | V |
| Minimum | 20.5 | REMAINDER | 1.5 | 4.0 | 0.2 | 11.5 | 0.1 | 0.1 | ||||
| Maximum | 0.06 | 23.5 | 6.00 | 3.0 | 6.0 | 0.4 | 13.5 | 0.3 | 0.45 | 0.3 | 1.0 | 0.3 |
| 0.2% Proof Stress (N/mm2 )[ksi] minimum | 300 [43.5] |
| Ultimate Tensile Strength (N/mm2) [ksi] minimum | 650[94.2] |
| Elongation (%) minimum | 35 |
| Hardness (HBN) | 270 max |
| Reduction of Area(%) minimum | 50 |
| Density (Kg.m-3) | 8000 |
| Magnetic Permeability | <1.05 |
| Young's Modulus (N/mm2) | 200 x 103 |
| Specific Heat 20°C (J.Kg-1.°K-1) | 500 |
| Electrical resistance, 20°C (μ.O.m) | 0.85 |
| Thermal conductivity, 20°C (W.m-1.°K-1) | 13.5 |