X12NiCrSi35-16 forgings
Open-die forged rings, flanges, discs, shafts, sleeves and tube sheets in the heat-resistant austenitic alloy X12NiCrSi35-16. Forged to your drawing, solution annealed, ultrasonically tested, and supplied with EN 10204 3.1 or 3.2 certification.
- EN material No.
- 1.4864
- UNS No.
- N08330
- Common name
- Alloy 330
- Standard
- EN 10095
- Alloy family
- Ni-Fe-Cr-Si
- Max. service
- ~1150 °C
X12NiCrSi35-16 is a heat-resistant austenitic nickel-iron-chromium-silicon alloy specified in EN 10095 under material number 1.4864. It contains 33–37 % nickel, 15–17 % chromium and 1.0–2.0 % silicon with iron as the balance, and is the European equivalent of UNS N08330, widely sold as Alloy 330 or RA330. The high nickel and silicon content resists carburisation and thermal cycling; chromium and silicon together resist oxidation and scaling in continuous service in air up to about 1150 °C (2100 °F).
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu Province, China, produces X12NiCrSi35-16 in forged ring, seamless rolled ring, flange, disc, bar, shaft, sleeve, bushing and tube sheet form to customer drawing, with EN 10204 3.1 or 3.2 material certification.
Key facts at a glance
- Designations: X12NiCrSi35-16, EN 1.4864, UNS N08330, Alloy 330 / AISI 330, SUH 330, 12Cr16Ni35
- Type: Solid-solution austenitic heat-resistant alloy. It is not precipitation hardenable and cannot be age hardened.
- Delivery condition: Solution annealed, typically 1050–1150 °C followed by rapid cooling.
- Typical strength: 552–586 MPa tensile, 207–296 MPa yield (Rp0.2), 30 % minimum elongation.
- Best at: Carburising and cyclic furnace atmospheres; radiant tubes, retorts, baskets, fans, hearth and grate parts.
- Not suited to: High-sulphur reducing atmospheres, and pressure-retaining creep service where an ASME code grade such as 800H is required.
1. Designations and equivalent grades
X12NiCrSi35-16 is the EN chemical designation; 1.4864 is the EN material number for the same alloy. When buying internationally the same material appears under the names below. Chemistry limits differ slightly between standards, so always state the standard you require on the purchase order.
| Standard / region | Designation | Notes |
|---|---|---|
| EN 10095 (Europe) | X12NiCrSi35-16 / 1.4864 | Primary specification for this grade |
| UNS (USA) | N08330 | Chemistry designation only |
| ASTM / AISI (USA) | Alloy 330, Type 330 | Bars and shapes to ASTM B511 |
| Trade names | RA330, Incoloy 330 | Proprietary names of the respective producers |
| DIN (Germany, superseded) | X12NiCrSi36-16 / 1.4864 | Older designation, same material number |
| JIS G4311 (Japan) | SUH 330 | Close equivalent |
| GB/T 1221 (China) | 12Cr16Ni35 (formerly 1Cr16Ni35) | Close equivalent |
| AFNOR (France) | Z12NCS35.16 | Close equivalent |
Equivalences are close but not always identical. Where a code case or a customer specification is involved, order to the exact standard rather than to an equivalent.
2. Chemical composition of X12NiCrSi35-16
The chemical composition of X12NiCrSi35-16 is given below to EN 10095, with the corresponding UNS N08330 limits from ASTM B511 for comparison. Silicon is the element that most distinguishes this alloy from ordinary austenitic stainless steels: at 1.0–2.0 % it strongly improves both oxidation and carburisation resistance.
| Element | X12NiCrSi35-16 (EN 10095) | UNS N08330 (ASTM B511) | Role in the alloy |
|---|---|---|---|
| Carbon (C) | 0.15 max | 0.08 max | Kept low for ductility and weldability |
| Silicon (Si) | 1.00 – 2.00 | 0.75 – 1.50 | Forms a protective silica sub-scale; the key carburisation barrier |
| Manganese (Mn) | 2.00 max | 2.00 max | Deoxidiser, austenite stabiliser |
| Phosphorus (P) | 0.045 max | 0.030 max | Residual, controlled |
| Sulphur (S) | 0.015 max | 0.030 max | Residual, controlled for hot workability |
| Chromium (Cr) | 15.0 – 17.0 | 17.0 – 20.0 | Forms the Cr₂O₃ oxide scale |
| Nickel (Ni) | 33.0 – 37.0 | 34.0 – 37.0 | Stabilises austenite; resists carburisation and chloride SCC |
| Nitrogen (N) | 0.11 max | n/a | Residual |
| Iron (Fe) | Balance | Balance | Matrix |
Note the difference in chromium and silicon limits: EN 1.4864 carries lower chromium and higher silicon than ASTM N08330. Specify one or the other; do not assume a certificate to one standard satisfies the other.
3. Mechanical properties
Values below are for X12NiCrSi35-16 in the solution annealed condition at room temperature. Because this is a solid-solution alloy, section size has only a modest effect on properties, but forgings are still tested per heat and per heat-treatment lot.
| Property | Metric | Imperial | Basis |
|---|---|---|---|
| Tensile strength, Rm | 483 MPa min; 552–586 typical | 70 ksi min; 80–85 typical | ASTM B511 / mill data |
| Yield strength, Rp0.2 | 207 MPa min; 207–296 typical | 30 ksi min; 30–43 typical | ASTM B511 / mill data |
| Elongation A₅ | 30 % min; 40–45 typical | 30 % min; 40–45 typical | ASTM B511 / mill data |
| Hardness | ≤ 90 HRB; 70–85 typical | ≤ 90 HRB; 70–85 typical | Mill data |
| Modulus of elasticity, 20 °C | 196 GPa | 28.4 × 10⁶ psi | Mill data |
| Impact toughness | Good; remains tough after long exposure, with no sigma-phase embrittlement | Alloy characteristic | |
Elevated-temperature strength falls steeply above roughly 700 °C. X12NiCrSi35-16 is selected for its scaling and carburisation resistance rather than for load-bearing creep strength; for pressure-retaining creep service, compare against Alloy 800H / N08810.
4. Physical properties
| Property | Value | Condition |
|---|---|---|
| Density | 7.94 g/cm³ (0.287 lb/in³) | 20 °C |
| Melting range | 1371 – 1427 °C (2500 – 2600 °F) | n/a |
| Coefficient of thermal expansion | ≈ 14.4 × 10⁻⁶ /K | 20 – 100 °C |
| Thermal conductivity | ≈ 12.6 W/m·K | 20 °C |
| Specific heat capacity | ≈ 460 J/kg·K | 20 °C |
| Electrical resistivity | ≈ 1.02 µΩ·m | 20 °C |
| Magnetic permeability | ≈ 1.02 (non-magnetic) | Solution annealed |
| Max. continuous service in air | ≈ 1150 °C (2100 °F) | Unstressed, air |
| Max. scaling temperature | ≈ 1100 °C per EN 10095 | Air |
Physical property values are typical and are given for engineering guidance. Service temperature limits depend on atmosphere, stress and whether exposure is continuous or cyclic. Confirm the figure against the actual duty before selecting the grade.
5. Heat treatment and delivery condition
X12NiCrSi35-16 cannot be hardened by heat treatment. It is a solid-solution alloy with no precipitation-hardening elements, so the solution-plus-ageing route used for grades such as Inconel 718 and 17-4PH does not apply here and must not be specified. Solution annealing is the only heat treatment used in production.
- Forging temperature range: approximately 1180 °C down to 950 °C. Finishing below about 950 °C risks cracking; the material must be reheated rather than forged cold.
- Solution annealing: typically 1050–1150 °C, held to through-heat the section, then cooled rapidly in water or forced air depending on section thickness.
- Stress relief: where required after heavy machining or welding, at a temperature agreed with the customer; note that any hold in the carbide-precipitation range should be kept short.
- Scale removal: pickling or shot blasting after annealing, as specified.
Strength can only be raised in this alloy by cold work, which is normally undesirable because it is lost on the first high-temperature exposure. Design for the annealed properties.
6. Forged product forms and size capability
Jiangyin Jiangnan Metal Co., Ltd. produces X12NiCrSi35-16 as open-die forgings and seamless rolled rings to customer drawing. The sizes below are the ranges routinely produced in this grade; larger or heavier pieces can often be accommodated, so send the drawing and let us confirm.
| Product form | Typical size range | Usual supply condition |
|---|---|---|
| Forged rings & seamless rolled rings | OD 200 – 3000 mm, wall 30 – 400 mm, height 30 – 800 mm | Solution annealed, rough machined |
| Forged flanges | OD 100 – 2500 mm, per drawing or ASME B16.5 / B16.47 | Solution annealed, rough or finish machined |
| Forged discs & blanks | Ø 150 – 2000 mm, thickness 20 – 600 mm | Solution annealed, rough machined |
| Forged round bars | Ø 80 – 800 mm, length to 6000 mm | Solution annealed, peeled or black |
| Forged shafts & spindles | Ø 100 – 900 mm, length to 6000 mm | Solution annealed, rough machined |
| Sleeves, bushings, hollow bars | OD 150 – 1500 mm, ID from 60 mm | Solution annealed, bored |
| Tube sheets & forged plate | Up to 2500 mm across, thickness 30 – 500 mm | Solution annealed, machined |
| Single piece weight | 20 kg – 8000 kg | n/a |
Forged to drawing with machining allowance agreed per piece. Finish machining, drilling and grooving to the customer's finished drawing is available in-house.
7. How we make an X12NiCrSi35-16 forging
The route below is the standard production sequence for this grade. Each stage is recorded against the heat number so the finished piece is fully traceable on the certificate.
- MeltingElectric arc furnace with AOD or VOD refining, and electro-slag remelting (ESR) where the customer specifies improved cleanliness and a tighter inclusion rating.
- Ingot inspection and croppingIngot surface conditioning, and cropping of the hot top and bottom to remove segregation and shrinkage.
- Open-die forgingHeated to about 1180 °C and forged with a controlled forging ratio to break down the as-cast structure and produce a wrought grain flow following the part contour. Rings are pierced and rolled on the ring mill.
- Solution annealing1050–1150 °C, through-heated and rapidly cooled, with a calibrated furnace chart recorded for the certificate.
- Rough or finish machiningTurning, boring and facing to the agreed machining allowance, or to the finished drawing where required.
- Non-destructive testingUltrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, plus liquid penetrant testing to ASTM E165 / EN ISO 3452 where specified.
- Certification and dispatchChemistry, mechanical results, heat treatment record and NDT report issued as an EN 10204 3.1 certificate, or 3.2 with third-party witness. Marked, preserved and packed for sea or air freight.
8. Testing, inspection and certification
Every X12NiCrSi35-16 forging leaves the works with an EN 10204 3.1 inspection certificate as standard. EN 10204 3.2 certification witnessed by a third party such as TÜV, SGS, BV, DNV or Lloyd's Register is available on request and should be stated at enquiry stage, since it affects lead time.
Chemical analysis
- Ladle analysis per heat
- Product analysis on request
- Spectrometer and combustion analysis for C and S
- PMI (positive material identification) on request
Mechanical testing
- Tensile test at room temperature (EN ISO 6892-1 / ASTM A370)
- Elevated-temperature tensile on request
- Hardness survey
- Charpy impact where specified
- Grain size and micro-examination on request
Non-destructive testing
- Ultrasonic testing: EN 10228-3, SEP 1921, ASTM A388
- Liquid penetrant: ASTM E165, EN ISO 3452
- Dimensional inspection report
- Intergranular corrosion test (ASTM A262 / G28) on request
Documentation
- EN 10204 3.1 as standard, 3.2 on request
- Full heat number traceability and hard stamping
- Heat treatment furnace charts
- NDT operator qualification records
- Certificate of origin and packing list for export
9. Where X12NiCrSi35-16 forgings are used
X12NiCrSi35-16 is chosen where a part has to survive repeated heating and cooling in a carburising or oxidising atmosphere, the conditions that scale and distort 304, 310 or 316 within months. The duties listed below are the ones we forge this grade for most often.
Heat treatment plant
- Carburising and hardening baskets, trays and fixtures
- Retorts and muffles
- Radiant tube components and supports
- Furnace fan hubs and shafts
- Hearth rolls, roller ends and bearing sleeves
- Grate bars and skid rails
Petrochemical and chemical
- Reformer and cracking furnace internals
- Pigtails, headers and support rings
- Forged flanges and nozzles for hot gas duty
- Thermowells and burner components
Power and incineration
- Boiler and superheater support hardware
- Ash handling and grate components
- Waste incinerator internals
- Flue gas duct rings and flanges
Ore, cement and glass
- Kiln nose ring and cooler segments
- Sinter plant hardware
- Glass furnace and lehr components
- Calciner and roaster internals
Typical forged shapes for these duties are rings, seamless rolled rings, flanges, discs, bushings, sleeves, shafts, spindles, tube sheets and machined blanks.
10. X12NiCrSi35-16 compared with other heat-resistant grades
Buyers usually arrive at X12NiCrSi35-16 while comparing it with 310S, 253 MA or Alloy 800H. The table sets out where each grade wins so you can confirm the choice before ordering.
| Grade | Ni % | Cr % | Strongest at | Choose it when |
|---|---|---|---|---|
| X12NiCrSi35-16 1.4864 / N08330 |
33–37 | 15–17 | Carburisation and thermal-cycling resistance | Furnace parts that cycle daily in a carburising or nitriding atmosphere |
| 310S 1.4845 / S31008 |
19–22 | 24–26 | Oxidation resistance at lower cost | Steady oxidising service and budget matters more than cycling life |
| 253 MA 1.4835 / S30815 |
10–12 | 20–22 | Strength-to-cost at high temperature | Load-bearing parts to ~1100 °C in oxidising service, low nickel budget |
| Alloy 800H 1.4958 / N08810 |
30–35 | 19–23 | Creep and stress-rupture strength | Pressure-retaining parts needing ASME code allowable stresses |
| Alloy 601 2.4851 / N06601 |
58–63 | 21–25 | Oxidation resistance above 1150 °C | The very hottest oxidising duty, where cost is secondary |
If the atmosphere carburises and the part cycles daily, X12NiCrSi35-16 is normally the right answer. If the part is pressure-retaining and creep governs the design, specify 800H instead. For steady oxidising service on a tighter budget, 310S or 253 MA will do the job. Above what 330 tolerates, move up to 601. Jiangyin Jiangnan Metal forges all five grades; see the full nickel alloy range.
11. Buying X12NiCrSi35-16 forgings from Jiangyin Jiangnan Metal
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China, supplying X12NiCrSi35-16 (EN 1.4864 / UNS N08330 / Alloy 330) forgings worldwide. We forge to the customer's drawing rather than selling from a fixed catalogue, so odd sizes, one-off replacement parts and small batches can all be quoted. Enquiries go to the engineering team, and a quotation normally comes back within one working day.
What you get with every order in this grade: forging to drawing, solution annealing with a recorded furnace chart, ultrasonic testing to EN 10228-3 / SEP 1921 / ASTM A388, full heat-number traceability, and an EN 10204 3.1 certificate, or 3.2 with third-party witness on request.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Works address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone / WhatsApp / WeChat
- +86 189 2135 9659
- sales@steelforgepieces.com
- Business type
- Open-die forging factory (manufacturer, not a trader)
- Export markets
- Europe, North America, the Middle East, South-East Asia, India, Japan and Korea
- Material range
- Carbon steel, alloy steel, tool steel, stainless steel and nickel alloys
- Standard certification
- EN 10204 3.1; EN 10204 3.2 on request
What to send with your enquiry
- A drawing (PDF, DWG or STEP), or the finished dimensions and the machining allowance you want
- Quantity, and whether this is a one-off, a spare or a repeat order
- The standard you require: EN 10095 or ASTM B511 chemistry
- Testing and certification: UT class, EN 10204 3.1 or 3.2, any customer specification
- Supply condition: black, rough machined or finish machined
- Destination port and required delivery date
12. Frequently asked questions about X12NiCrSi35-16
What is X12NiCrSi35-16?
X12NiCrSi35-16 is a heat-resistant austenitic nickel-iron-chromium-silicon alloy specified in EN 10095, with the EN material number 1.4864. It contains 33–37 % nickel, 15–17 % chromium and 1.0–2.0 % silicon, with iron as the balance. The high nickel and silicon give it strong resistance to carburisation, and the chromium plus silicon give resistance to oxidation and scaling at high temperature.
What is the UNS equivalent of X12NiCrSi35-16?
X12NiCrSi35-16 corresponds to UNS N08330, commonly sold as Alloy 330, AISI 330 or under the trade name RA330. The Japanese equivalent is SUH 330 (JIS G4311) and the Chinese equivalent is 12Cr16Ni35, formerly designated 1Cr16Ni35, in GB/T 1221.
What is the maximum service temperature of X12NiCrSi35-16?
X12NiCrSi35-16 is normally used in continuous service in air up to about 1150 °C (2100 °F). EN 10095 gives a maximum scaling temperature in air of about 1100 °C. The real limit depends on the atmosphere, the stress on the part and whether service is continuous or cyclic, so confirm the temperature against the specific duty rather than relying on a single headline figure.
Can X12NiCrSi35-16 be hardened by heat treatment?
No. X12NiCrSi35-16 is a solid-solution alloy and is not precipitation hardenable, so it cannot be strengthened by ageing. Forgings are supplied solution annealed, typically at 1050–1150 °C followed by rapid cooling. Strength can only be raised by cold work, which is generally undesirable for high-temperature service because it is lost on the first hot exposure.
Which standards cover X12NiCrSi35-16 and UNS N08330?
The European standard is EN 10095, heat resisting steels and nickel alloys, which lists X12NiCrSi35-16 / 1.4864. On the ASTM side, UNS N08330 is covered by ASTM B511 for bars and shapes, B535 for seamless pipe and tube, B536 for plate, sheet and strip, B546 for welded pipe and B710 for welded tube. There is no dedicated ASTM forging specification for N08330, and it does not fall within the scope of ASTM B564. Forgings are therefore ordered to EN 10095 or ASTM B511 chemistry, with mechanical properties and testing agreed on the purchase order.
What is the difference between Alloy 330 and Incoloy 800H?
Alloy 330 (X12NiCrSi35-16 / N08330) carries around 34–37 % nickel with 1.0–2.0 % silicon, which makes it markedly better at resisting carburisation and thermal cycling. Incoloy 800H (N08810) has around 30–35 % nickel with lower silicon but controlled carbon and grain size, giving higher creep and stress-rupture strength for pressure-retaining service. Choose Alloy 330 for carburising and cyclic furnace atmospheres, and 800H where ASME code creep strength is required.
What forged shapes can be produced in X12NiCrSi35-16?
Jiangyin Jiangnan Metal Co., Ltd. produces X12NiCrSi35-16 as open-die forged rings and seamless rolled rings, flanges, discs and blanks, round bars, shafts, sleeves, bushings, hollow bars and tube sheets, all forged to the customer's drawing and supplied black, rough machined or finish machined.
Is X12NiCrSi35-16 magnetic?
No. X12NiCrSi35-16 is fully austenitic at all temperatures and is essentially non-magnetic in the solution annealed condition, with relative permeability close to 1.02. Because it stays austenitic it is also not subject to sigma-phase embrittlement, unlike lower-nickel heat-resistant grades.
What certification is supplied with X12NiCrSi35-16 forgings?
An EN 10204 3.1 inspection certificate is supplied as standard, covering heat chemistry, mechanical test results and heat treatment records with full heat traceability. EN 10204 3.2 certification witnessed by a third party such as TÜV, SGS, BV or Lloyd's Register is available on request. Ultrasonic testing is performed to EN 10228-3, SEP 1921 or ASTM A388 as specified on the order.
How do I get a price for X12NiCrSi35-16 forgings?
Send a drawing or the finished dimensions, the quantity, the required standard and any testing or certification requirements to sales@steelforgepieces.com, or call +86 189 2135 9659. Jiangyin Jiangnan Metal Co., Ltd. is located at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, and normally returns a quotation within one working day.
14. Request a quotation for X12NiCrSi35-16 forgings
Send a drawing or the dimensions and we will come back with a firm price, forging weight and lead time, normally within one working day. You can also email sales@steelforgepieces.com or call +86 189 2135 9659 directly.
Technical data reviewed by the Jiangyin Jiangnan Metal engineering department against EN 10095, ASTM B511 and published mill data. Published 18 May 2016. Last reviewed 2 September 2026. Values are typical and given for engineering guidance; they are not a warranty of properties for a specific application.