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Super Austenitic Stainless Steels – Corrosion Resistance Beyond 316L
High-performance stainless steels with exceptional pitting resistance and durability for seawater, acid, and high-chloride environments. Trusted in offshore, chemical, and cleanroom applications.
What Is Super Austenitic Stainless Steel?
Super austenitic stainless steels are a class of high-alloyed, nitrogen-enhanced austenitic grades that offer superior corrosion resistance compared to standard 304/316.
These grades are characterized by:
Very high chromium, molybdenum, and nickel content
Fully austenitic structure, with optional nitrogen to increase strength
Excellent resistance to pitting (PREN ≥ 40), crevice, and stress corrosion
Ideal for aggressive chemical and chloride-rich environments
Key Grades:
| Grade | PREN | Main Feature |
|---|---|---|
| 254SMO (S31254) | 42–45 | Excellent pitting resistance, seawater approved |
| 654SMO (S32654) | >50 | One of the highest corrosion-resistant grades |
| 904L (N08904) | 35 | Acid and chloride resistant, copper added |
| 1925hMo / 1925hN | 44–46 | Excellent crevice and intergranular corrosion resistance |
Products Link
Optional product specifications
| Property | Details |
|---|---|
| Forms Available | Plate, sheet, bar, tube, pipe, flange, fitting |
| Standards | ASTM A240, A312, A182, EN 1.4547 / 1.4539 / 1.4565 |
| Plate Thickness | 3mm – 100mm |
| Pipe Size | NPS 1/2” – 24”, SCH10 – SCH160 / XXS |
| Bar Diameter | Ø6mm – 300mm |
| Finish Options | 2B, No.1, HL, BA, pickled, mirror polish |
| Condition | Solution annealed |
| Certifications | EN10204 3.1 / 3.2, NORSOK, PED, NACE MR0175 |
Product Forms: Plate, tube, pipe, bar, flange, forging 100% PMI-tested and intergranular corrosion-tested (per ASTM A262)
Processing & Packaging
Waterjet / plasma / laser cut available
Bright annealed / pickled / mirror polishing
PMI, UT, IGC (A262), and mechanical testing
Marked with grade, size, heat no. & QR code
Export-ready crate, pallet or seaworthy packaging
Why Buy From Xishang?
- Full range of super austenitic stainless grades in stock
- Customized cutting, forming, machining services
- Support for sour service, NACE & offshore certifications
- Traceability: MTC, heat number, batch ID, lab tests
- Global export packaging + fast logistics
- Small MOQ available for project trials or maintenance
Frequently Asked Questions
Q1: How does 254SMO compare to 316L?
A:
254SMO offers more than 2–3x the pitting resistance (PREN 42 vs 25), and superior performance in seawater and aggressive chloride environments.
Q2: Is 904L still suitable for sulfuric acid resistance?
A:
Yes, especially where reducing acids like H₂SO₄ or mixed environments exist. 904L’s copper content improves resistance.
Q3: Do you offer 654SMO for seawater?
A:
Yes. We stock and machine 654SMO (S32654) for the most demanding seawater or FGD applications.
Q4: Can I order polished super austenitic tubes?
A:
Yes. Tube polish options include 180–600 grit, mirror or sanitary finishes.
Q5: What is your standard delivery time?
A:
For stocked items: 3–5 days. Custom cut: 5–10 working days depending on size/volume.
Let us know your required grade
For applications where corrosion resistance is mission-critical, Xishang supplies certified super austenitic stainless steels tailored to marine, chemical, pharmaceutical and power projects.
