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.
Chemical Specification of Alloy 254
| 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 | 3.0 | 6.0 | 0.4 | 13.5 | 0.3 | 0.45 | 0.3 | 1.0 | 0.3 |
Basic Properties of Alloy 254- Mechanical Properties
| 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 |
View Physical Properties of ALLOY ALLOY254 Physical Properties of Alloy 254
| 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 |
Applications of Alloy 254
Chemical Process Industry: Urea Production, Organic and Fatty Acids, High halide concentrations
Marine Industry and Shipbuilding: Piping, Pumps, Valves, Heat exchangers
Oil and Gas Industry: Heat exchangers, Piping, Valves, Pumps
Pulp and Paper Industry: Bleach plant, vats, drums, press rolls, piping
Power Industry: Flue gas scrubbers
Desalination plant: Piping, Condensers
Alloy 254 Features
- High strength compared to 316L and 317L austenitic stainless steels
- Excellent ductility and impact strength at both ambient and sub-zero temperatures
- Non-magnetic
- Higher resistance to abrasion, erosion and cavitation erosion than 316 and 317 stainless
- Listed in MR-01-75 for sour service oilfield applications
KEY Features of Alloy 254
- Resistant to crevice corrosion in seawater
- Excellent corrosion resistance in seawater and concentrated halide environments
- High resistance to stress corrosion cracking
- Good resistance to erosion corrosion
- Excellent ductility and impact strength at both ambient and sub-zero temperatures
- Low magnetic permeability