UNS S31254 254 SMO F52

Alloy 254 (UNS S31254)


Alloy 254, is a high alloy austenitic stainless steel which is supplied in the hot worked and annealed condition. Significant additions of Mo, Ni and Cu gives this alloy a good resistance to pitting and crevice corrosion, especially in environments containing halide ions e.g. chloride, bromide and fluoride solutions. It is therefore widely used in applications in brackish water, seawater, pulp mill bleach plants and other chloride process streams, where it can be a cost-effective alternative to more expensive nickel and titanium alloys in such environments.

The high alloy additions ensure that it has a strength nearly twice that of 3xx austenitic stainless steels. It retains excellent ductility and toughness at both elevated and sub-zero temperatures. It can generally be formed and welded in the same way as other 3xx alloys, but the high work hardening rate means that machining may require slower speeds / more power.

Key Features:

1.High alloy additions means that it has a Pitting Resistance Equivalent number (PREN) of  ≥42
2.Excellent corrosion resistance in seawater and concentrated halide environments
3.High resistance to stress corrosion cracking
4.Resistant to crevice corrosion in seawater
5.Good resistance to erosion corrosion
6.Excellent ductility and impact strength at both ambient and sub-zero temperatures
7.Low magnetic permeability


1.Process industry equipment in urea production, organic & fatty acids, high halide concentration environments
2.Oil & Gas industry heat exchangers, piping, valves and pumps
3.Power generation for flue gas desulphurisation (FGD) applications
4.Marine and shipbuilding piping, pumps, valves and heat exchangers
5.Water treatment facilities, such as piping and condensers in desalination plant
6.Pulp and paper processing for bleaching plant, vats, drums, press rolls and piping