# UNS S32760 Forgings (ASTM A182 F55 / EN 1.4501)

**UNS S32760 is a 25 percent chromium super duplex stainless steel, about half ferrite and half austenite, alloyed with nitrogen and carrying copper and tungsten at 0.50 to 1.00 percent each. The forging designation is ASTM A182 Grade F55; the European designation is EN 1.4501, X2CrNiMoCuWN25-7-4. Material is supplied with a pitting resistance equivalent number of 40.0 or higher and a minimum 0.2 percent proof stress of 550 MPa.**

Jiangyin Jiangnan Metal Co., Ltd. melts, forges, ring-rolls, heat treats, machines and tests this grade on one site at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Telephone +86 189 2135 9659. Email sales@steelforgepieces.com.

Source page: https://www.steelforgepieces.com/Stainless-Steel/UNS-S32760.html

## Grade record

| Field | Detail |
|---|---|
| UNS number | S32760 |
| Forging specification | ASTM A182 / A182M Grade F55, ASTM A473 |
| EN material number | 1.4501 |
| EN name | X2CrNiMoCuWN25-7-4 |
| Type | 25Cr super duplex stainless steel, copper and tungsten bearing |
| Structure | Ferrite and austenite, approximately 50:50 |
| PREN (Cr + 3.3 Mo + 16 N) | 40.0 minimum |
| Rp0.2 minimum | 550 MPa (79.8 ksi) |
| Tensile strength | 750 to 895 MPa (109 to 130 ksi) |
| Elongation minimum | 25 percent |
| Certification | EN 10204 Type 3.1, or Type 3.2 third party |
| Manufacturer | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China |

## Chemical composition, ASTM A182 Grade F55, weight percent

| Element | Min | Max |
|---|---|---|
| Carbon | — | 0.030 |
| Manganese | — | 1.00 |
| Silicon | — | 1.00 |
| Phosphorus | — | 0.030 |
| Sulfur | — | 0.010 |
| Chromium | 24.00 | 26.00 |
| Nickel | 6.00 | 8.00 |
| Molybdenum | 3.00 | 4.00 |
| Copper | 0.50 | 1.00 |
| Tungsten | 0.50 | 1.00 |
| Nitrogen | 0.20 | 0.30 |
| Iron | Remainder | |

PREN is calculated as percent Cr + 3.3 × percent Mo + 16 × percent N, the form written into NORSOK M-630 MDS D57, which sets the limit at 40.0 minimum. Standard 22 percent chromium duplex sits nearer 35. For a two-phase steel the limiting value is the lower PREN of the two phases, so ferrite balance after solution annealing matters as much as the bulk analysis.

## Mechanical properties, solution annealed and quenched

| Property | ASTM A182 F55 | EN 10088-3 (1.4501) | NORSOK MDS D57 |
|---|---|---|---|
| Tensile strength Rm | 750 to 895 MPa | 730 to 930 MPa | 750 MPa min |
| Proof stress Rp0.2 min | 550 MPa | 530 MPa | 550 MPa min |
| Elongation min | 25 percent | 25 percent | 25 percent min |
| Reduction of area min | 45 percent | — | — |
| Hardness | 270 HB max | — | Tested per heat and heat treatment load |
| Impact, ambient | 80 J min | — | — |
| Impact at −46 °C | 45 J average, 35 J single | — | 45 J average, 35 J single, ASTM A370 |

The three columns are three different acceptance documents, not conflicting data. ASTM A182 F55 governs forgings, EN 10088-3 covers bar and section, and NORSOK M-630 MDS D57 applies to 25Cr duplex bars up to 200 mm thickness and is written on the mechanical properties of S32760. Typical production yield runs higher than the minimum, up to around 600 MPa. Notch ductility stays good down to about −50 °C.

## Physical properties, typical

| Property | Value |
|---|---|
| Density | 7.81 g/cm³ |
| Young's modulus | 199 kN/mm² (199 GPa) |
| Magnetic permeability | 33, the ferrite phase is magnetic |

## Heat treatment

- After hot working, cool below 538 °C before heat treatment begins.
- Solution treat and water quench. The ASTM A182 solutioning temperature for F55 is 1100 to 1140 °C minimum.
- Space pieces in the furnace and quench so that air and water circulate freely around each one, as NORSOK MDS D57 requires. Inadequate spacing is the usual cause of a failed ferrite count or G48 test on heavy sections.
- Target structure 35 to 55 percent ferrite, free from intermetallic phases and precipitates at 400 times magnification.
- The solution annealing temperature and holding time are stated on the certificate.
- Hot working window for this grade is roughly 1100 to 1250 °C per supplier guidance.

## Test and release package

| Item | Standard and acceptance |
|---|---|
| Melting and refining | EF, LF and VOD on 30 t or 60 t units. MDS D57 requires AOD refining or equivalent |
| Chemical analysis | Optical emission spectrometry to ASTM E415, PREN calculated and stated, 40.0 minimum |
| Tensile test | ASTM A370 |
| Impact test | Charpy V-notch, ASTM A370, −46 °C, 45 J average and 35 J single minimum |
| Micrographic examination | 10 × 10 mm minimum area, ferrite 35 to 55 percent to ASTM E562, free of intermetallics at 400× |
| Corrosion test | ASTM G48 Method A, 50 °C, 24 hours, no pitting at 20× and weight loss below 4.0 g/m², placed with an accredited third-party laboratory |
| Extent of testing | One set of impact, tensile, hardness, microstructure and corrosion tests per heat and heat treatment load |
| Test sampling | To 50 mm thickness, mid thickness. Above 50 mm, at least one quarter T from nearest surface |
| Volumetric examination | EN 10228-3, SEP 1921 or ASTM A388. Magnetic particle to ASTM E709 on request |
| Surface finish | White pickled, machined surfaces not pickled |
| Weld repair | Not accepted on product supplied to MDS D57 |
| Certificate | EN 10204 Type 3.1 standard, Type 3.2 witnessed by BV, DNV, LR, SGS or TUV on request |

## Designations and standards

UNS S32760. EN 1.4501. EN name X2CrNiMoCuWN25-7-4. ASTM A182 F55 and A473 for forgings, A479 and A276 condition A for bar, A240 for plate and sheet, A988 for HIP products. EN 10088-3 for bar and section. AFNOR Z3CND25.06Az. NORSOK M-630 MDS D57 for bars, with manufacturing qualification to NORSOK M-650. NACE MR0175 / ISO 15156-3 for sour service. ASME approved for pressure vessel use. PED 97/23/EC. Trade names Zeron 100, a registered trademark of Rolled Alloys, and Seacol 760; listed for cross reference only.

## Products forged in S32760

Seamless rolled rings, forged rings, valve seat rings and retaining rings. Flanges to ASME B16.5, B16.47 and API 6A. Round, flat and square bars and blocks. Shafts, spindles, rotors and valve stems. Discs, tube sheets and covers. Hollow cylinders, sleeves and bushings. Valve and wellhead parts including bodies, bonnets, blocks, chokes, connectors, spools and manifolds.

## Corrosion performance and grade selection

High resistance to pitting and crevice corrosion, and to stress corrosion cracking in chloride and sour environments, with high resistance to general corrosion, erosion corrosion and corrosion fatigue. Strength is above both austenitic grades and 22 percent chromium duplex, which makes this the usual upgrade when 316L or 2205 is being lost to pitting or chloride cracking.

Against S32750 and 2507: both are super duplex, both are specified above PREN 40 and both perform similarly in seawater. The chemistry difference is the copper and tungsten in S32760. Published literature for this grade records its heaviest service in seawater, sour gas and sulfuric acid duty. For plain chloride service either grade is normally acceptable, so selection usually follows the project specification and product availability rather than a clear technical gap. Duplex structures are limited at elevated temperature by intermetallic precipitation, so state the design temperature at enquiry.

## Typical industries

Offshore oil and gas, including Christmas trees, wellheads, chokes, connectors, manifolds, risers and BOP parts. Seawater and firewater systems. Seawater reverse osmosis desalination. Chemical and pharmaceutical process plant and sulfuric acid service. Flue gas desulfurisation and pollution control. Pulp and paper digesters and liquor tanks. Mining and metallurgical equipment.

## Manufacturing capability

| Field | Detail |
|---|---|
| Melting | EF, LF, VOD, VIM, VAR, ESR. Maximum heat 60 t. Stainless and duplex run EF to LF to VOD |
| Forging | Open-die presses 6,300 t, 4,000 t, 2,000 t. Hammers 750 kg to 5 t |
| Ring rolling | Radial-axial mills to 6,000 mm, 3,000 mm and 1,000 mm outside diameter |
| Heat treatment | 14 furnaces. Car-bottom chambers to 8,000 mm long. Pit furnaces 15,000 mm deep by 1,500 mm diameter |
| Machining | Vertical lathes to 5,000 mm swing, horizontal lathes to 14,000 mm, CNC deep-hole drilling to 1,600 mm by 10,000 mm |
| Ring size range | 50 mm to 6,000 mm outside diameter |
| Maximum single piece | 30,000 kg |
| Order terms | Minimum 10 kg, no minimum piece count, lead time 20 to 60 days |
| Approvals | CCS, BV, DNV, LR, NK |
| Established | 1997, 460 staff including 9 senior engineers, 32 intermediate engineers and 140 technicians |

## Questions

**Is UNS S32760 the same as ASTM A182 F55?**
Yes. ASTM A182 / A182M assigns identification symbol F55 to UNS S32760, described as 25 chromium, 7 nickel, 3.5 molybdenum, modified with nitrogen and tungsten.

**What heat treatment is applied?**
Cooled below 538 °C after hot working, then solution treated and water quenched at the ASTM A182 solutioning temperature for F55, 1100 to 1140 °C minimum. Temperature and holding time are recorded on the certificate.

**Can NORSOK requirements be met?**
MDS D57 acceptance criteria are built into the standard test package for this grade. Manufacture to the data sheet also calls for qualification under NORSOK M-650, which should be raised at enquiry stage rather than after order placement.

**What size and weight is possible?**
Seamless rolled rings to 6,000 mm outside diameter, rings from 50 mm by the upset and punch route, shafts to 14,000 mm turned length, discs to 5,000 mm machined diameter, single piece weight to 30,000 kg.

**What is needed to quote?**
A drawing or dimension list, the governing specification, quantity, machining condition, NDT requirement and certificate type. Quotations normally go back within one working day.

## Contact

Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone, WhatsApp and WeChat: +86 189 2135 9659
Email: sales@steelforgepieces.com
Business hours: Monday to Saturday, 08:00 to 17:30 China Standard Time (UTC+8)
Web: https://www.steelforgepieces.com/

Data is for guidance. The purchase specification and the issued mill certificate govern. Last reviewed 8 October 2026.