Duplex 2205 and super duplex 2507 / Zeron 100 flanges and fittings
Two-phase stainless steels with roughly twice the yield strength of 316L and much better chloride resistance. We manufacture flanges and fittings in F51, F60, F53 and F55.
Product forms and specifications
| Product | Specification and grade |
|---|---|
| Forged flanges | ASTM A182 F51 (S31803), F60 (S32205), F53 (S32750), F55 (S32760) |
| Butt-weld fittings | ASTM A815 WPS31803, WPS32205, WPS32750, WPS32760 |
| Forged socket-weld and threaded fittings | ASTM A182 F51, F60, F53, F55 |
| Pipe (stocked and sourced) | ASTM A790 seamless and welded; A928 for large welded sizes |
| Bolting | ASTM A1082 and A276 bar for duplex and super duplex studs and nuts |
We manufacture the flanges, fittings and fabrications listed. Pipe is supplied from stock or sourced from approved mills.
Chemistry and strength
| Grade | UNS / W.Nr. | Nominal chemistry (%) | Min tensile / yield, MPa | PREN |
|---|---|---|---|---|
| 2205 (F51) | S31803 / 1.4462 | Cr 21–23, Ni 4.5–6.5, Mo 2.5–3.5, N 0.08–0.20 | 620 / 450 | about 34–35 |
| 2205 (F60) | S32205 / 1.4462 | Cr 22–23, Ni 4.5–6.5, Mo 3.0–3.5, N 0.14–0.20 | 655 / 450 | about 35 |
| 2507 (F53) | S32750 / 1.4410 | Cr 24–26, Ni 6–8, Mo 3–5, N 0.24–0.32 | 800 / 550 | 40 and above |
| Zeron 100 type (F55) | S32760 / 1.4501 | Cr 24–26, Ni 6–8, Mo 3–4, W 0.5–1.0, Cu 0.5–1.0, N 0.20–0.30 | 750 / 550 | 40 and above |
For design use the values in the current edition of the specification your order calls for.
Where it is used
Duplex grades are used where 316L would suffer chloride pitting or stress-corrosion cracking: seawater and brine lines, desalination, offshore firewater, chemical process piping and mining slurry lines.
The higher strength often allows lighter wall sections. Heat treatment and phase balance matter more than in austenitic steels, so we can test ferrite content and run ASTM A923 or G48 tests for intermetallic phases when required.
Questions buyers ask
What is the difference between F51 and F60?
Both are 2205 duplex. F60 (S32205) has tighter limits on chromium, molybdenum and nitrogen, giving slightly better corrosion resistance and strength. Many flanges are dual-certified to F51 and F60.
Is F55 the same as Zeron 100?
Zeron 100 is a trade name for super duplex to UNS S32760, which is ASTM A182 grade F55. It adds tungsten and copper to the 25Cr super duplex base.
Can you provide ferrite and A923 test reports?
Yes. Ferrite measurement and ASTM A923 Method A, B or C testing are available on request and are listed on the test certificates.
Get a price for Duplex and super duplex
Tell us the grades, standards, sizes and quantities. Our estimation team replies from info@teshigroup.com, usually within one working day for standard items.
Drawings, BOQ spreadsheets and QAPs are easiest by email. Attach them to a message to info@teshigroup.com and mention your project name.