Uranus 52N+ is Aperam/Industeel's trade name for the copper-bearing super duplex alloy UNS S32550 (also cross-referenced to S32520), EN 1.4507. It shares the same super duplex backbone as its sibling Uranus 47N+ — roughly 25% chromium, a similar molybdenum addition, and a nitrogen-driven PREN (pitting resistance equivalent) guaranteed above 40 — but adds 1.5-2.5% copper, which 47N+ does not carry. That copper addition is deliberate: it doesn't move the PREN number much, but it meaningfully improves resistance to reducing acids like sulfuric and phosphoric, which chromium, molybdenum, and nitrogen alone don't address as effectively.
The result is a super duplex grade positioned specifically for phosphoric acid and fertilizer production, pollution-control equipment, pulp and paper processing, and petrochemical service where acidic (not just chloride-rich) conditions are the primary corrosion driver, in addition to the marine and offshore applications common to the rest of the duplex family. Mechanically it behaves like any super duplex: a roughly 50/50 austenite-ferrite structure with a minimum guaranteed yield strength around 550 MPa, well above standard 2205.
| Standard | Designation |
|---|---|
| UNS | S32550 (S32520) |
| Wnr. (Werkstoffnummer) | 1.4507 |
| DIN / EN | X2CrNiMoCuN25-6-3 |
| ASTM | A240 (plate/sheet), A182 Gr. F61 (forgings), A789/A790 (tube/pipe) |
| Element | Content |
|---|---|
| Chromium (Cr) | 24.0 – 27.0% |
| Nickel (Ni) | 4.50 – 6.50% |
| Molybdenum (Mo) | 2.90 – 3.90% |
| Copper (Cu) | 1.50 – 2.50% |
| Nitrogen (N) | 0.10 – 0.25% |
| Manganese (Mn) | 1.50% max |
| Silicon (Si) | 1.00% max |
| Carbon (C) | 0.040% max |
| Phosphorus (P) | 0.040% max |
| Sulfur (S) | 0.030% max |
Composition per ASTM A240 for UNS S32550. Estimated PREN (Cr + 3.3×Mo + 16×N) is 40 or higher; the 1.5-2.5% copper addition is the defining difference from Uranus 47N+ and is aimed at reducing-acid resistance rather than PREN itself.
Uranus 52N+ cuts much like its sibling 47N+ — both are super duplex grades with alloy content well above standard 2205, and both generate higher cutting forces and edge temperatures than standard duplex because of a harder, more abrasive ferrite phase. The copper addition that distinguishes 52N+ chemically doesn't change its machining behavior in any significant way; copper at this level affects corrosion performance, not shear strength or work-hardening tendency.
As with any super duplex grade, treat 52N+ as a step up in demand from standard 2205: favor a tough, wear- and heat-resistant coated carbide over an aggressive fine edge, keep depths of cut and feeds conservative rather than borrowed from lower-alloy duplex, and prioritize rigidity in both the machine and the workholding. Coolant delivery matters more here than on standard duplex given the higher heat generated at the cutting edge, and chatter or excessive tool overhang will show up quickly as edge chipping rather than gradual wear.
| Operation | Vc (m/min) | Vc (SFM) |
|---|---|---|
| Turning | 55 – 78 | 180 – 255 |
| Milling | 38 – 52 | 125 – 170 |
| Parting | 25 – 35 | 80 – 115 |
| Grooving | 32 – 45 | 105 – 150 |
| Drilling | 15 – 22 | 50 – 70 |
Values assume favorable cutting conditions: a well-matched insert grade, rigid tool and workpiece clamping, short tool overhang, and adequate coolant. Reduce speeds further for interrupted cuts or thin-wall parts prone to deflection.
| Grade | Coating | ISO Application Range |
|---|---|---|
| FM199 | PVD | M30 – M40 |
| FM2553 | CVD | M30 |
| Grade | Coating | ISO Application Range |
|---|---|---|
| FM199 | PVD | M40 |
| FM2553 | CVD | M30 |
| Grade | Coating | ISO Application Range |
|---|---|---|
| FM125 | PVD | M30 – M40 |
Ready to cut Uranus 52N+? Shop FM Carbide inserts matched to this alloy's turning, parting, grooving, and milling requirements.
Shop Turning & Grooving Inserts Shop Milling Inserts| Parameter | Value |
|---|---|
| Honing Size | 0.04 – 0.06 mm / 0.0016 – 0.0024" |
| Rake Angle | 3° – 6° |
| Land Angle | Neutral to slightly positive |
| Land Width | 0.20 – 0.30 mm / 0.008 – 0.012" |