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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.
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 |
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 |
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
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
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