Summary
Both grades are about half ferrite and half austenite. The higher alloy content of 2507 buys resistance to seawater and hot chlorides. For scrap, higher nickel and molybdenum make 2507 the more valuable of the two. Keep both away from nickel alloy lots.
Side by Side
| Duplex 2205 | Super duplex 2507 | |
|---|---|---|
| PREN | About 35 | Above 40 |
| UNS | S32205 / S31803 | S32750 |
| Typical service | Process piping, tanks, vessels | Seawater, offshore, desalination high-pressure |
| Forgings | A182 F51 / F60 | A182 F53 |
Composition Compared
Nominal compositions compared element by element. Values are the nominal figures from each grade page; change either grade to compare others.
On a handheld XRF: the clearest differences between Duplex 2205 and Super duplex 2507 are iron (67.23% vs 62.92%), chromium (22.5% vs 25%) and nickel (5.5% vs 7%). Light elements such as aluminium, silicon, carbon and nitrogen need a light-element instrument, OES or a laboratory.
On the XRF
Switch the grade to see how the fingerprint changes. See how XRF sorts nickel alloys.
FAQ
What is the main difference between Duplex 2205 and super duplex 2507?
Super duplex 2507 has more chromium, molybdenum, nickel and nitrogen than duplex 2205. Composition side by side and why the two scraps are not mixed. PREN above 40 against about 35. Both are magnetic, so XRF is needed to tell them apart.
Can Duplex 2205 and Super duplex 2507 scrap be mixed?
No. Keep them separate. A melt shop buying Duplex 2205 expects Duplex 2205 chemistry, so a few pieces of Super Duplex 2507 can push a heat out of limits and lead to a re-sort or a lower offer.
What are the UNS numbers of Duplex 2205 and Super duplex 2507?
Duplex 2205 is UNS S32205 / S31803 and Super duplex 2507 is UNS S32750.
Which has more nickel, Duplex 2205 or Super duplex 2507?
Super duplex 2507, with about 7% nickel against about 5.5% in Duplex 2205, using the nominal values on this site.
Sources and Review
Composition figures on this page are the nominal values from each grade's own page on this site, where the producer datasheet or standard is named in full. The comparison widget reads the same values. The sources behind the grades are listed below.
- Rolled Alloys, 2205 Duplex Stainless data sheet (bulletin 1007USe, 2015): Duplex 2205 Buyer, Importer and Exporter
- Rolled Alloys, Alloy 2507 data sheet (2022): Super Duplex 2507 Buyer, Importer and Exporter
Published by Mipra Steel, Khetwadi, Mumbai · Last updated