# X3CrNiMoN27-5-2 (EN 1.4460) Duplex Stainless Steel Forgings

**X3CrNiMoN27-5-2, material number EN 1.4460, is an austenitic-ferritic duplex stainless steel with 25 to 28 % chromium, 4.5 to 6.5 % nickel, 1.3 to 2.0 % molybdenum and 0.05 to 0.20 % nitrogen.**

The two-phase structure carries a proof strength of at least 460 MPa, roughly twice that of a standard austenitic grade, together with resistance to pitting, crevice corrosion, chloride stress corrosion cracking and corrosion fatigue. The grade is listed in EN 10088-1, EN 10088-3 and EN 10088-5, in EN 10250-4 for open die forgings and in EN 10297-2 for seamless tube.

Jiangyin Jiangnan Metal Co., Ltd. melts this grade on site through the electric arc furnace, ladle furnace and vacuum oxygen decarburisation route, then forges, heat treats, machines and certifies it in the same works. The certificate traces the part to its melt number rather than to a purchased billet.

## Supplier

| Field | Detail |
|---|---|
| Legal name | Jiangyin Jiangnan Metal Co., Ltd. |
| Business | Integrated melting works, open-die forge and ring rolling mill |
| Established | 1997 |
| Plant | No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China |
| Telephone | +86 189 2135 9659 |
| Email | sales@steelforgepieces.com |
| Page | https://www.steelforgepieces.com/Stainless-Steel/X3CrNiMoN27-5-2.html |
| Approvals | CCS, BV, DNV, LR, NK |
| Minimum order | 10 kg, no minimum piece count |
| Lead time | 20 to 60 days |

## Grade summary

| Field | Value |
|---|---|
| EN name | X3CrNiMoN27-5-2 (also written X3CrNiMoN27.5.2) |
| EN number | 1.4460 |
| Type | Austenitic-ferritic stainless steel (duplex) |
| Density | 7.8 g/cm3 |
| PREN, calculated | approx. 34 |
| Delivery condition | Solution annealed and quenched (+AT) |
| Standards | EN 10088-1, EN 10088-3, EN 10088-5, EN 10250-4, EN 10297-2 |

## Chemical composition, % by weight

| C | Si | Mn | P | S | Cr | Ni | Mo | N | Fe |
|---|---|---|---|---|---|---|---|---|---|
| ≤ 0.05 | ≤ 1.00 | ≤ 2.00 | ≤ 0.035 | ≤ 0.030 | 25.0–28.0 | 4.5–6.5 | 1.30–2.00 | 0.05–0.20 | Balance |

Sulphur is set deliberately. EN 10088-3 states that a controlled sulphur content of 0.015 to 0.030 % is recommended and permitted for machinability, 0.008 to 0.030 % for weldability, and 0.015 % maximum for polishability. The three cannot all be optimised in one heat, so state which one governs the part on the enquiry.

## Mechanical properties, specified, room temperature

| Property | Symbol | Value |
|---|---|---|
| Tensile strength | Rm | 620–880 MPa |
| 0.2 % proof strength | Rp0.2 | ≥ 460 MPa |
| Elongation | A | ≥ 20 % |
| Hardness, annealed | HB | ≤ 260 |
| Modulus of elasticity | E | 200 GPa |

## Mechanical properties, typical measured values

| Property | Metric | Imperial |
|---|---|---|
| Ultimate tensile strength | 750 MPa | 110 ksi |
| Yield / proof strength | 510 MPa | 74 ksi |
| Elongation at break | 21 % | 21 % |
| Brinell hardness | 220 HB | 220 HB |
| Charpy V-notch impact | 83 J | 61 ft-lb |
| Fatigue strength | 330 MPa | 48 ksi |
| Shear strength | 470 MPa | 68 ksi |
| Shear modulus | 80 GPa | 12 x 10^6 psi |
| Poisson's ratio | 0.27 | 0.27 |

## Elevated temperature

| Temperature | Rp0.2 | Modulus E | Linear expansion |
|---|---|---|---|
| 20 °C | ≥ 460 MPa | 200 GPa | – |
| 100 °C | ≥ 360 MPa | 194 GPa | 13.0 x 10-6 K-1 |
| 200 °C | ≥ 310 MPa | 186 GPa | 13.5 x 10-6 K-1 |
| 300 °C | – | 180 GPa | 14.0 x 10-6 K-1 |

## Physical and thermal data

| Property | Value |
|---|---|
| Density | 7.8 g/cm3 |
| Thermal conductivity | 15 W/m·K |
| Specific heat capacity | 480 J/kg·K |
| Thermal expansion | 13 µm/m·K |
| Latent heat of fusion | 300 J/g |
| Melting onset (solidus) | 1390 °C |
| Melting completion (liquidus) | 1430 °C |
| Maximum temperature, corrosion service | 450 °C |

Like other duplex steels, 1.4460 embrittles after long exposure between roughly 300 and 900 °C, where sigma phase and 475 °C embrittlement develop. Design continuous service below about 300 °C, and below about 450 °C in corrosive media. The grade is not creep resisting.

## Equivalent grades

Cross-references disagree in the published literature. Virgamet and Langley Alloys equate 1.4460 with AISI 329 and UNS S32900. The duplex comparison table on Wikipedia maps 1.4460 to UNS S31200. The compositions below show why both positions can be argued: each overlaps 1.4460 without matching it.

| Standard | Designation | Cr % | Ni % | Mo % | N % |
|---|---|---|---|---|---|
| EN / DIN | X3CrNiMoN27-5-2 · 1.4460 | 25.0–28.0 | 4.5–6.5 | 1.30–2.00 | 0.05–0.20 |
| ASTM / AISI | AISI 329 · S32900 · Alloy 7Mo | 23.0–28.0 | 2.5–5.0 | 1.00–2.00 | – |
| ASTM | S31200 · 44LN · Grade F50 | 24.0–26.0 | 5.5–6.5 | 1.20–2.00 | 0.14–0.20 |
| AFNOR | Z5CND27-05 Az | 26.0–27.0 | 4.5–5.0 | 1.30–2.00 | 0.05–0.20 |
| SS (Sweden) | SS 2324 | 24.0–27.0 | 4.5–7.0 | 1.30–1.80 | – |
| UNE (Spain) | X8CrNiMo26-6 · F-3552 | 24.0–27.0 | 4.5–7.0 | 1.30–1.80 | ≤ 0.10 |
| UNE (Spain) | X8CrNiMo27-05 · F-3309 | 26.0–28.0 | 4.0–5.0 | 1.30–2.00 | – |
| ASTM cast | CD6MN · J93371 · A781 Gr. 3A | 24.0–27.0 | 4.0–6.0 | 1.75–2.50 | 0.15–0.25 |

These are near-equivalents, not drop-in substitutions. Order against the EN 1.4460 limits and name the standard the project is audited to.

## Corrosion behaviour

The duplex structure, 25 to 28 % chromium and 1.3 to 2.0 % molybdenum give good resistance to pitting, crevice corrosion, intergranular corrosion, corrosion fatigue and chloride stress corrosion cracking. Intergranular resistance is retained after welding.

The calculated PREN is about 34, using %Cr + 3.3 x %Mo + 16 x %N. A PREN of 32 to 35 is commonly treated as the minimum for seawater service and super duplex grades sit near 40 and above, so 1.4460 is at the lower edge of seawater capability. For hot aerated seawater or sour service, compare against 2507 or Zeron 100 type grades first. Some suppliers list 1.4460 as super duplex because of its chromium content; on PREN it is a standard duplex.

## Machining, welding and forming

- **Machining.** With a controlled sulphur content it machines more easily than 1.4462, which suits parts with heavy turning, drilling and threading content. Corrosion resistance is slightly lower than 1.4462, and higher sulphur costs polishability.
- **Welding.** Weldable, with intergranular corrosion resistance retained after welding. Weld as an austenitic material with low, controlled heat input and a held interpass temperature.
- **Forming.** Hot and cold forming are both possible. Duplex steels work-harden faster and spring back more than austenitics. After hot forming, solution anneal and quench to restore the phase balance.
- **Heat treatment.** Supplied solution annealed and quenched. Not hardenable by heat treatment. Avoid slow cooling through the sigma phase range.

## Forged forms supplied

- **Bar.** Round, square, rectangular, flat and hexagonal bars, stepped shafts, machining blanks.
- **Hollow sections.** Hollow bars, bored cylinders, sleeves, bushes, bushings, heavy-wall pipe sections, barrels, casings, shells, hubs, housings.
- **Rings.** Seamless rolled rings, forged and contoured rings, flange and gear ring blanks, retaining rings, valve seat rings.
- **Discs and shapes.** Discs, blocks, plates, tube sheets, covers, propeller shafts, pump shafting, spindles, pistons, stirrers, bolts, nuts, valve parts.

## Working envelope

| Product | Size limit | Set by |
|---|---|---|
| Seamless rolled rings | to OD 6,000 mm | 6 m radial-axial ring mill |
| Forged shafts | to 14,000 mm turned length | C61160 lathe, 15 m well furnace |
| Discs, tube sheets, blocks | to 5,000 mm machined diameter | 5,000 mm vertical turning lathe |
| Bored cylinders, hollow shafts | to 1,600 mm dia x 10,000 mm | CNC deep-hole drilling machine |
| Single-piece weight | to 30,000 kg | 60 t heat size, 6,300 t press |
| Minimum ring size | from OD 50 mm | Upset and punch route |

## Applications

Pumps and pump shafts, valves and valve parts, screws, heat exchangers for power engineering, radiators, tanks, chlorine-bearing housings, pipelines, special anchors, stirrers and sleeves, across chemical, cryogenic, pulp and paper, marine and aviation plant. Marine propeller shafting, pump shafting, pistons, bolts and nuts are the common forged applications.

## Testing and certification

EN 10204 3.1 mill test certificates as standard, 3.2 third-party certification on request. Available tests: spectrometer analysis, tensile and proof strength at room or elevated temperature, Charpy V-notch impact, Brinell hardness, ferrite content, microstructure examination for sigma phase, ultrasonic examination, dye penetrant inspection, intergranular corrosion testing and ASTM G48 pitting testing. The works holds CCS, BV, DNV, LR and NK approvals.

## Questions buyers ask

**What is X3CrNiMoN27-5-2 steel?**
An austenitic-ferritic duplex stainless steel, EN number 1.4460, with 25.0 to 28.0 % chromium, 4.5 to 6.5 % nickel, 1.30 to 2.00 % molybdenum and 0.05 to 0.20 % nitrogen. Proof strength is at least 460 MPa, about double a standard austenitic grade, with resistance to pitting, crevice corrosion, chloride stress corrosion cracking and corrosion fatigue.

**What is the UNS or ASTM equivalent of 1.4460?**
Sources disagree. Virgamet and Langley Alloys equate it with AISI 329 and UNS S32900; the Wikipedia duplex table maps it to UNS S31200. Other near-equivalents are AFNOR Z5CND27-05 Az, SS 2324, F-3552, F-3309 and the cast grade CD6MN / J93371. None matches exactly.

**Is it a super duplex stainless steel?**
No. The calculated PREN is about 34, below the value near 40 that defines super duplex grades such as 1.4410 / UNS S32750.

**How does it compare with 1.4462 (2205)?**
It machines more easily but has slightly lower corrosion resistance. EN 10088-3 permits 0.015 to 0.030 % controlled sulphur where machinability matters, which is how the machinability-improved versions are produced.

**Can it be welded?**
Yes, with low and controlled heat input, keeping exposure between roughly 300 and 900 °C short. Intergranular corrosion resistance is retained after welding.

**What sizes can be produced?**
Rolled rings to 6,000 mm OD, single pieces to 30 t, shafts turned to 14,000 mm, discs to 5,000 mm diameter, bored cylinders to 1,600 mm dia x 10,000 mm. Minimum order 10 kg, lead time 20 to 60 days.

**What certification comes with the material?**
EN 10204 3.1 as standard, 3.2 third-party certification on request. Chemical analysis, tensile, impact, hardness, ferrite content, microstructure, ultrasonic and dye penetrant examination, intergranular corrosion and ASTM G48 pitting tests can all be included.

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Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Telephone +86 189 2135 9659. Email sales@steelforgepieces.com.

Data compiled from EN 10088-1, EN 10088-3 and EN 10250-4 grade listings and published material databases. Values apply to the solution annealed condition and do not replace the governing standard or an agreed order specification. Last reviewed 10 October 2026.