Why do buyers confuse 1.4507 and Zeron 100®?
Buyers confuse the two because the market talks about performance classes — "super duplex", "F55", "PREN 40" — as if each were a single grade. It is not. A performance class is a bracket that several distinct alloys fall into, and 1.4507 and the alloy behind Zeron 100® are two different residents of that bracket.
Ask three suppliers whether they are the same and you often get three answers, because datasheets list a wall of overlapping cross-references without flagging which element actually differs. Getting it right is not academic: it changes what appears on the mill test certificate, whether a third-party inspector signs off, and occasionally whether a component passes a corrosion acceptance test years into service.
Is Zeron 100® a grade or a brand?
Zeron 100® is a brand — a registered trademark — not a national grade designation. That single fact resolves most of the confusion.
1.4507 — a designation from the EN standard
1.4507 is the numeric Werkstoff designation in EN 10088 for the super duplex grade X2CrNiMoCuN25-6-3. The name spells out the chemistry: X2 = ultra-low carbon (≤ 0.030%), Cr25 = ~25% chromium, Ni6 = ~6% nickel, Mo3 = ~3% molybdenum, plus deliberate copper and nitrogen. Its closest home in the UNS system is S32520 / S32550. It is a public, non-proprietary grade any qualified mill can certify to.
Zeron 100® — a trademarked S32760 product
Zeron 100® denotes a tightly controlled super duplex product supplied to UNS S32760 chemistry, cross-referenced as EN 1.4501 (X2CrNiMoCuWN25-7-4) and, in ASTM/ASME procurement, A182 Grade F55. Note the extra letter in that EN name — the W is tungsten, an element 1.4507 does not deliberately contain.
"Super duplex" is the family. 1.4507 and S32760 / 1.4501 are two different members of it. Zeron 100® is one company's branded version of the S32760 member.
How do 1.4507 and Zeron 100® compare on chemistry?
The values below are nominal, drawn from the respective standard specifications. Actual mill certificates report the heat analysis within these ranges.
| Parameter | 1.4507 (X2CrNiMoCuN25-6-3) | Zeron 100® — S32760 / 1.4501 |
|---|---|---|
| Type | Standard grade designation | Trademarked S32760 product |
| Nearest UNS | S32520 / S32550 | S32760 |
| EN number | 1.4507 | 1.4501 |
| ASTM forging grade | — | A182 F55 |
| Chromium, Cr % | 24.0 – 26.0 | 24.0 – 26.0 |
| Nickel, Ni % | 6.0 – 8.0 (nom. ~6) | 6.0 – 8.0 (nom. ~7) |
| Molybdenum, Mo % | 3.0 – 4.0 | 3.0 – 4.0 (nom. ~3.6) |
| Copper, Cu % | 1.0 – 2.5 | 0.5 – 1.0 |
| Tungsten, W % | — none deliberate | 0.5 – 1.0 |
| Nitrogen, N % | 0.20 – 0.30 | 0.20 – 0.30 |
| Carbon, C % | ≤ 0.030 | ≤ 0.030 |
| PREN (min class) | ≥ 40 | ≥ 40 (per spec) |
| Min. yield Rp0.2 | ~500 MPa | ~550 MPa |
| Grade listed in NACE MR0175* | Yes (solution-annealed) | Yes (solution-annealed) |
| Upper service temp | ~280 °C | ~300 °C |
* "Listed in NACE MR0175" describes the alloy grade, not a certification held by any supplier. Nominal values for general engineering guidance — confirm exact limits against the governing edition of the applicable standard before purchase.
Does the tungsten in Zeron 100® matter?
Yes, when the specification calls up S32760 or F55 by number — otherwise, usually not. The deliberate difference comes down to tungsten, backed by a slightly higher nickel target and a lower copper band.
Tungsten behaves much like molybdenum: it strengthens the passive film and improves resistance to localized pitting and crevice corrosion, especially in warm, stagnant seawater where crevices form under gaskets, deposits and flange faces. That is why it enters the pitting-resistance calculation directly.
PREN — two formulas, one target
The standard index is PREN = %Cr + 3.3×%Mo + 16×%N. For tungsten-bearing grades such as S32760 the accepted variant is PRENₓ = %Cr + 3.3×(%Mo + 0.5×%W) + 16×%N. Both grades clear the same PREN ≥ 40 super-duplex threshold — S32760 gets part of the way there via tungsten, whereas 1.4507 relies on chromium, molybdenum and nitrogen alone.
A tungsten-free 1.4507 heat, however good its corrosion performance, does not satisfy a purchase order written for UNS S32760 — because the certificate must report tungsten within 0.5–1.0%. — Jiangsu Liangyi Materials Engineering Team
When can you treat 1.4507 and Zeron 100® as interchangeable?
The safe rule: let the specification decide, not the marketing.
Treat them as functionally equivalent when…
- The spec asks only for "super duplex, PREN ≥ 40" without naming a UNS or trade name.
- The duty is general chloride exposure or NACE MR0175 sour service, not qualified against one specific chemistry.
- You need copper's advantage in reducing acids (sulfuric, phosphoric) — here 1.4507's higher copper band is the stronger card.
Specify the exact grade — no substitution — when…
- The line item names UNS S32760, EN 1.4501, ASTM A182 F55, or Zeron 100® explicitly.
- A NORSOK, DNV or client qualification package was built and tested against a tungsten-bearing S32760 chemistry.
- Warm-seawater crevice corrosion is the governing failure mode and the design margin leans on tungsten.
- You are matching existing installed material for weld compatibility and long-term consistency.
"Zeron 100®" on a drawing is a trademark reference. Unless the client contractually mandates that brand, you can normally satisfy it with a fully certified generic UNS S32760 / F55 forging — the same base grade, without the brand premium. Confirm acceptance in writing first.
We forge the grade your specification actually names.
Whether your drawing calls up EN 1.4507 (X2CrNiMoCuN25-6-3) or the tungsten-bearing UNS S32760 / ASTM A182 F55 behind Zeron 100®, Jiangsu Liangyi forges to the exact grade and chemistry your order specifies, supplied with an EN 10204 3.1 material test certificate. Independent EN 10204 3.2 inspection by a third-party agency can be arranged on request.
Explore 1.4507 super duplex forging parts →How do the two grades appear on a mill test certificate?
On a properly issued material test certificate the ambiguity disappears — a certificate reports a specific grade against a specific standard, with the actual heat analysis. This is where you confirm what you actually bought.
- A 1.4507 certificate references EN 10088-3 · X2CrNiMoCuN25-6-3 and reports no deliberate tungsten line.
- An S32760 / F55 certificate references ASTM A182 F55 / EN 1.4501 and reports a tungsten value within 0.5–1.0%.
- For multi-standard export projects, a single certificate can legitimately dual-reference EN and UNS — provided the reported chemistry genuinely satisfies both named grades.
That last point is the honest test of any "1.4507 = S32760" claim: it holds only if the heat analysis on the paper meets both specifications, tungsten included. If you would like this comparison mapped against your own drawing, our engineers can review it against our 1.4507 (X2CrNiMoCuN25-6-3) super duplex forging parts and confirm the grade for your service.
Frequently asked questions
Is 1.4507 the same as Zeron 100®?
Is Zeron 100® a grade or a brand?
What is the correct UNS number for 1.4507?
Which grade is better for sulfuric or phosphoric acid?
Can Jiangsu Liangyi supply both grades?
Sources & standards referenced
- EN 10088-3 — Stainless steels: technical delivery conditions for bars, rods and sections (chemical composition of 1.4507 and 1.4501).
- EN 10250-4 — Open die steel forgings for general engineering purposes: stainless steels.
- ASTM A182/A182M — Forged stainless flanges, fittings and valve parts (Grade F55 = UNS S32760).
- NACE MR0175 / ISO 15156-3 — Materials for use in H₂S-containing environments in oil and gas production (sour-service qualification).
- Rolled Alloys — ZERON® 100 super duplex (UNS S32760 / 1.4501 / F55) product data (trademark owner).