ASTM 254smo 1.4547 Stainless Steel Pipe Smo254 Hollow Bar
254SMo is an austenitic stainless steel specifically developed for use in halide-containing environments such as seawater. This steel demonstrates superior performance particularly in halide-containing acids and offers excellent resistance to uniform corrosion. With carbon content below 0.02%, it is classified as pure austenitic stainless steel, and when carbon content is under 0.01%, it qualifies as super austenitic stainless steel.
Key Features of Inox 254SMo
As a super stainless steel, 254SMo represents a high-alloy stainless steel containing elevated levels of nickel, chromium, and molybdenum. The 6% molybdenum content provides exceptional local corrosion resistance, making it particularly effective against pitting corrosion (PI ≥ 40) and stress corrosion in demanding conditions including seawater, aeration, gaps, and low-speed scouring. This performance makes 254SMo a viable alternative to nickel-based alloys and titanium alloys.
The steel exhibits superior high-temperature resistance and corrosion performance compared to standard 304 stainless steel. Its metallurgical structure consists of a stable austenitic formation, ensuring reliability across various applications.
Extensive field testing confirms 254SMo maintains high crevice corrosion resistance in seawater, even at elevated temperatures—a characteristic shared by only a few stainless steel types. In acidic solutions and oxidizing halide environments typical of paper bleaching processes, 254SMo demonstrates corrosion resistance comparable to premium nickel-based alloys and titanium.
The high nitrogen content enhances mechanical strength beyond conventional austenitic stainless steels, while maintaining excellent ductility, impact strength, and weldability. The elevated molybdenum content results in higher oxidation rates during annealing, producing a slightly rougher surface after pickling than standard stainless steels, though this does not compromise corrosion performance.
Technical Specifications
Material Standards
| Standard |
UNS |
Werkstoff Nr. |
EN |
SS |
AFNOR |
| 254 SMO |
S31254 |
1.4529 |
X1CrNiMoCuN20-18-7 |
2378* |
Z1 CNDU 20.18.06AZ* |
Chemical Composition
| Element |
Content (%) |
| Iron, Fe |
55.69 |
| Chromium, Cr |
20 |
| Nickel, Ni |
18 |
| Molybdenum, Mo |
6.1 |
| Nitrogen, N |
0.20 |
| Carbon, C |
0.010 |
Mechanical Properties
| Properties |
Metric |
Imperial |
| Tensile strength |
680 MPa |
98600 psi |
| Yield strength |
300 MPa |
43500 psi |
| Modulus of elasticity |
195 GPa |
28300 ksi |
| Shear modulus |
75 GPa |
10900 ksi |
| Poisson's ratio |
0.30 |
0.30 |
| Elongation at break |
50 % |
50 % |
| Hardness, Brinell |
210 |
210 |
Applications
- Ocean: Marine structures in sea environments, seawater desalination, marine aquaculture, seawater heat exchange
- Environmental Protection: Flue gas desulfurization for thermal power generation, wastewater treatment
- Energy: Nuclear power generation, comprehensive coal utilization, ocean wave power generation
- Petrochemical Industry: Refining operations, chemical processing equipment
- Food: Salt production, soy sauce brewing processes
- High Chloride Environments: Paper industry applications, various bleaching systems
- Other specialized industrial applications
Product Images
Related Material Designations
Grade 254SMo
Type 254SMo
Inox 254SMo
AISI 254SMo
SUS 254SMo
1.4547
UNS S31254
Acero 254SMo
