Super Austenitic Stainless Steel
Super austenitic stainless steel is considered to be stainless steel with a pitting resistance equivalent number (PREN) greater than 40. This is usually attributed to alloys with high amounts of molybdenum, usually 6% or higher. Under solution annealing conditions, these grades have higher yield strength than austenitic grades.
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Super Austenitic Stainless Steel Supplier | 254SMO, 904L, AL-6XN | Huaxiao Metal
Super austenitic stainless steel is a high-performance alloy designed to provide excellent corrosion resistance in highly corrosive environments. Rich in nickel, chromium, molybdenum and nitrogen, these steels are ideal for seawater, chemical processing, pulp and paper, and petrochemical industries.
Huaxiao Metal supplies high-quality super austenitic stainless steels such as 254SMO, 904L and AL-6XN. All products are strictly quality controlled and certified to international standards.
Super Austenitic Stainless Steel Specifications
| Grades | 904L(N08904，,14539), 254SMO-S31254, NO8367-NO8926, 6 mo super austenitic stainless steel, etc. |
|---|---|
| Product Range | Stainless Steel Sheet/plate, coil, strip, tube, bar, wire, etc. |
| Size | Customized according to customer requirements. |
| Standard | UNS N08904、DIN1.4539、ASTM A240、SUS890LUNS S31254、DIN/EN 1.4547、ASTM A280、ASME SA-280, etc. Shipping Port: Shanghai, Tianjin, Guangzhou, Shenzhen, Ningbo China, etc. |
| Shipping Port | Shanghai, Tianjin, Guangzhou, Shenzhen, Ningbo China, etc. |
| Delivery Time | 10-35 days. |
Features of Super Austenitic Stainless Steel
Super austenitic stainless steel has high nickel and molybdenum content and also contains copper and nitrogen elements, so it is difficult to melt, and easy to bend and crack. Therefore, the technical requirements for super austenitic stainless steel are the most stringent and difficult steel grades among all stainless steel. Like other commonly used Cr-Ni austenite, super austenitic stainless steel has good hot and cold workability.
| Grade | UNS | Main Alloy Elements | Key Features |
|---|---|---|---|
| 254SMO | S31254 | 20% Cr, 18% Ni, 6% Mo, N | Excellent pitting and crevice corrosion resistance |
| 904L | N08904 | 20% Cr, 25% Ni, 4.5% Mo, Cu | Strong sulfuric acid resistance, non-magnetic |
| AL-6XN | N08367 | 20.5% Cr, 24% Ni, 6.3% Mo, N | Ideal for seawater, bioprocessing, and chlorides |
Super Austenitic Stainless Steel 904L
About 904l Stainless Steel
Super austenitic stainless steel 904L (N08904, 14539) is a low-carbon, high-nickel, molybdenum austenitic stainless and acid-resistant steel. It is a proprietary material imported from France H·S. It has good activation-passivation transformation ability, excellent corrosion resistance, good corrosion resistance in non-oxidizing acids such as sulfuric acid, acetic acid, formic acid, and phosphoric acid, and good corrosion resistance in neutral chloride-containing media.
904l Stainless Steel Performance
It has good pitting resistance and good resistance to crevice corrosion and stress corrosion. It is suitable for sulfuric acid of various concentrations below 70°C, and it has good corrosion resistance in the mixed acid of formic acid and acetic acid in any concentration and temperature under normal pressure.
904l Stainless Steel Composition
| C | Cr | Ni | Mo | Si | Mn | P | S | Cu |
|---|---|---|---|---|---|---|---|---|
| ≤0.02 | 19-23 | 23-28 | 4-5 | ≤1 | – | – | ≤0.045 | 1-2 |
904l Stainless Steel Properties in Physical and Mechanical:
- Density: 8.0g/cm3.
- Tensile strength: σb≥520Mpa.
- Elongation: δ≥35%.
Metallographic structure of 904L stainless steel:
904L is a completely austenitic structure. Compared with austenitic stainless steel with high molybdenum content, 904L is not sensitive to the precipitation of ferrite and α phase.
Super Austenitic Stainless Steel Grades 254SMO
About 254SMO Stainless Steel
254SMO(s31254、f44、1.4547) is a grade of super austenitic stainless steel. Due to its high molybdenum content, it has extremely high resistance to pitting corrosion and crevice corrosion. It is often used in environments containing halide such as seawater. 254SMO also has good uniform corrosion resistance. Especially in acids containing halide, the steel is superior to ordinary stainless steel. Its C content is <0.03%, so it is called pure austenitic stainless steel (<0.01% is also called super austenitic stainless steel).
254SMO Chemical Composition
| Grade | C(%) | Mn(%) | P(%) | S(%) | Si(%) | Cr(%) | Ni(%) | Mo(%) | N(%) | Ce(%) |
|---|---|---|---|---|---|---|---|---|---|---|
| 254SMO | ≤0.02 | ≤1.0 | ≤0.040 | ≤0.030 | ≤0.8 | 19.5-20.5 | 17.5-18.5 | 6.0-6.5 | 0.18-0.2 | 0.03-0.08 |
254SMO Physical Properties
| Modulus Elasticity | Thermal Conductivity | Specific Heat | Density | Melting Range | Member |
|---|---|---|---|---|---|
| 10 6pounds/inch² | Btu/hft°F | Btu/lb°F | g/cm3 | Column 5 Value | — |
| 29 | 7.5 | 0.120 | 8.1 | 1320-1390 | 1.003 |
*All values are measured at room temperature.
Application Super Austenitic Stainless Steel
- Petroleum and petrochemical equipment, such as bellows in petrochemical equipment;
- Pulp and paper bleaching equipment, such as pulp digester and bleaching equipment;
- The power plant flue gas desulfurization device, the main components used: the tower body, flue, door panel, internal parts, sprinkler system, etc.;
- Offshore systems or seawater treatment, such as thin-walled condenser tubes and seawater desalination equipment cooled by seawater in power plants;
- Salt industry, such as salt making or desalination equipment;
- Other
FAQ
What is the difference between 254SMO and 904L?
254SMO contains higher molybdenum and nitrogen, giving it superior resistance to pitting and crevice corrosion compared to 904L.
Can these materials be used in seawater?
Yes. Especially 254SMO and AL-6XN are optimized for seawater and chloride-rich environments.
Do you supply cut-to-length pipes or custom fittings?
Yes, we offer full customization, including pipes, tubes, flanges, and fittings according to client specifications.
What is Super Austenitic Stainless Steel?
Super austenitic stainless steel is considered to be stainless steel with a pitting resistance equivalent number (PREN) greater than 40. This is usually attributed to alloys with high amounts of molybdenum, usually 6% or higher. Under solution annealing conditions, these grades have higher yield strength than austenitic grades.
Super austenitic grades are iron-based austenitic face-centered cubic stainless steel alloys. While retaining the advantages of austenitic steel such as formability, general corrosion resistance, and strength, these also ensure excellent resistance to crevice corrosion and pitting (due to chloride) and excellent weldability.