254 SMO®
UNS S31254
High-performance superaustenitic stainless steel for extremely corrosive environments, seawater, chlorides and made-to-drawing CNC machined parts.
A superaustenitic stainless steel for severe corrosion
254 SMO® - UNS S31254 is a superaustenitic stainless steel designed to work in highly corrosive environments where conventional stainless steels such as 316L or 317L may not provide sufficient resistance.
Its high molybdenum, chromium and nitrogen content provides excellent performance against pitting corrosion, crevice corrosion, chlorides, seawater and aggressive chemical processes.
Material identification
What is 254 SMO®?
It is a high-performance superaustenitic stainless steel developed for applications where localised corrosion represents a critical risk.
It is used in parts and components exposed to seawater, salts, acids, aggressive chemicals and conditions where material failure can generate operational costs or safety issues.
Highly alloyed
High chromium, nickel, molybdenum and nitrogen content.
Chlorides
Very good performance in environments with salts and seawater.
High PREN
PREN above 42 for resistance to localised corrosion.
Critical use
Suitable for applications where material durability is essential.
Why it is used in extremely corrosive environments
254 SMO® is selected when the part needs to resist chlorides, localised corrosion and service conditions where standard stainless steels are not enough.
| Property | Technical advantage |
|---|---|
| Pitting resistance | Very good performance against localised corrosion in the presence of chlorides. |
| Crevice corrosion resistance | Applicable in areas with joints, complex geometries or possible accumulation points. |
| High mechanical strength | Allows components exposed to stress to work while maintaining durability. |
| Marine environments | Especially interesting for seawater, offshore and desalination applications. |
| Chemical processes | Suitable for environments with aggressive chemicals and severe media. |
| PREN above 42 | Places the material among the austenitic stainless steels with higher resistance to localised corrosion. |
A chemistry designed to resist chlorides
The performance of 254 SMO® is based on a composition enriched with molybdenum, chromium, nickel, nitrogen and copper.
This combination improves resistance to pitting corrosion, crevice corrosion and continuous exposure to salts or aggressive fluids. In CNC machining, it requires control of tooling, cooling and cutting strategy.
Typical chemical composition
Where 254 SMO® is used
This material is mainly used in industries where components are exposed to high chloride concentrations, aggressive acids or seawater.
Desalination
Seawater
Chemical industry
Petrochemical
Pulp and paper
Heat exchangers
Offshore
Pharmaceutical
CNC machining of 254 SMO®
Machining 254 SMO® can be more demanding than machining standard stainless steels due to its high alloy content and strength.
At AREM-CNC, we manufacture parts in special materials from drawings, physical samples or technical specifications, adapting the process to the material, geometry, tolerances, finish and required documentation.
Made-to-drawing production
- Special screws and studs.
- Precision machined nuts.
- Technical washers, bushings and spacers.
- Pins, shafts and custom components.
- Flanges, plugs, rings and industrial parts.
- Components for pumps, valves and chemical systems.
Controlled production for severe environments
CNC manufacturing transforms 254 SMO® into customised, traceable components prepared for environments where corrosion is a critical factor.
Custom geometry
Manufacturing adapted to the customer’s drawing, physical sample or specification.
Special material
A solution for projects where standard stainless steels are not enough.
Dimensional control
Verification of dimensions, tolerances and technical requirements of the part.
Technical finishes
Finishes adapted to the real function and service conditions of the part.
Flexible series
Production of one-off parts, prototypes, short runs or medium runs.
Traceability
Documentation associated with the material, batch and manufacturing process.
Technical documentation for special materials
In high-performance materials, traceability is key to verifying origin, composition, batch and suitability for the application.
Depending on project requirements, we can work with material certificates, heat numbers, dimensional verification, manufacturing batches and associated final documentation.
Frequently asked questions about 254 SMO®
What is 254 SMO®?
It is a superaustenitic stainless steel identified as UNS S31254, designed for highly corrosive environments and chloride applications.
Where is 254 SMO® used?
It is used in desalination, seawater, chemical industry, petrochemical, offshore, heat exchangers, condensers, pulp and paper, pharmaceutical and food industries.
What advantage does it offer over standard stainless steels?
Its high molybdenum, chromium and nitrogen content improves resistance to localised corrosion, pitting, crevice corrosion and chloride environments.
Can made-to-drawing parts be manufactured in 254 SMO®?
Yes. CNC machining can be used to manufacture screws, nuts, washers, bushings, shafts, pins, flanges and special components in 254 SMO®, provided that the design is feasible.
Why is traceability important?
Because in special materials it is essential to verify composition, batch, heat number and documentation associated with the manufactured part.
Do you need 254 SMO® parts manufactured?
Send us your drawing, physical sample or technical specification. We will review material, tolerances, geometry, finish and documentation requirements to manufacture a reliable and traceable solution.