What is UNS N06075?
UNS N06075 is a wrought nickel-chromium alloy, roughly 75% nickel and 20% chromium, with small controlled additions of titanium and carbon. Chromium provides solid-solution strengthening and forms the protective oxide. Titanium and carbon combine as MC carbides that sit on the grain boundaries and restrict grain-boundary sliding under load.
There is no gamma-prime phase in this alloy, so it cannot be age hardened. That is the trade-off: lower strength than Nimonic 80A or Waspaloy, but far better formability and weldability.
The alloy dates from the 1940s, when it was developed for early gas turbine hardware. It is still specified for hot parts running in oxidising atmospheres that do not carry heavy sustained load: furnace internals, heat-treatment fixtures, turbine casings and shroud rings, and nuclear structural hardware outside the pressure boundary.
The practical selection window is 550 °C to 1100 °C. Below 550 °C, stabilised austenitic stainless grades such as 321 and 347 do the same job for less money. Above 815 °C under continuous load, an age-hardenable grade is the correct answer.
Equivalent designations and product standards
UNS N06075, Nimonic 75, Alloy 75, W.Nr. 2.4951, W.Nr. 2.4630 and NiCr20Ti all describe the same base alloy. Composition windows and test requirements differ slightly between specifications, so the purchase order should name the governing specification and the delivery condition.
| System | Designation | Scope / product form |
|---|---|---|
| UNS (USA) | N06075 | Unified Numbering System identifier |
| Trade names | Nimonic 75, Alloy 75, Nickel Alloy 75 | Nimonic is a registered trademark of Special Metals Corporation |
| Werkstoff (DE) | 2.4951 / 2.4630 | 2.4951 normally denotes the solution-annealed condition |
| DIN / ISO name | NiCr20Ti | Chemical-symbol designation |
| BS (UK) | HR5, HR504 | Bar and forging stock |
| BS (UK) | HR203 | Sheet and plate |
| BS (UK) | HR403 | Tube |
| MSRR | MSRR 7004 / 7104 | Bar and sheet, Rolls-Royce material specification |
| DIN | 17742, 17750–17752 | Wrought nickel-alloy product standards |
| ISO | 9723, 9724, 9725 | Bar, wire and forgings in nickel alloys |
| AFNOR (FR) | NC20T | French designation |
| GOST (RU) | EI435 | Approximate Russian counterpart, verify against the certificate |
| GB (CN) | GH3030 / GH30 | Approximate Chinese counterpart, composition overlaps but is not a drop-in substitute |
A note on ASTM: UNS N06075 is not covered by ASTM B637, which applies to precipitation-hardening nickel alloys such as N07718 and N07750. Where an ASTM route is mandated for N06075, order to the relevant fittings or forging standard and state the acceptance criteria explicitly.
Chemical composition of UNS N06075
The chemical composition of UNS N06075 is 18.0–21.0% chromium, 0.20–0.60% titanium and 0.08–0.15% carbon, with nickel as the balance and iron limited to 5.0% maximum, all by weight percent. The chromium level produces the adherent Cr₂O₃ scale that gives the alloy its oxidation resistance. The titanium and carbon form the carbides that carry its creep resistance.
| Element | Min | Max | Role |
|---|---|---|---|
| Nickel, Ni | — | Balance | Austenitic matrix |
| Chromium, Cr | 18.00 | 21.00 | Oxidation and scaling resistance, solid-solution strengthening |
| Titanium, Ti | 0.20 | 0.60 | MC carbide former, grain-boundary stabilisation |
| Carbon, C | 0.08 | 0.15 | Carbide former |
| Iron, Fe | — | 5.00 | Residual |
| Silicon, Si | — | 1.00 | Deoxidiser, residual |
| Manganese, Mn | — | 1.00 | Deoxidiser, residual |
| Copper, Cu | — | 0.50 | Residual |
| Aluminium, Al | — | 0.30 | Residual, held low to avoid gamma-prime formation |
| Sulfur, S | — | 0.015 | Typical mill limit, controls hot ductility |
Composition windows vary marginally between BS, DIN and ISO specifications. Jiangyin Jiangnan Metal Co., Ltd. reports both ladle and product analysis on the EN 10204 3.1 mill certificate for every heat.
Mechanical properties of UNS N06075
Solution annealed at room temperature, UNS N06075 forgings typically develop a tensile strength of 750 MPa (109 ksi), a 0.2% proof stress of 275 MPa (40 ksi) and 42% elongation, with a modulus of elasticity of 206 GPa. Typical values shift with section size, forging reduction and grain size. Specification minima sit below typical values and are the figures a purchase order should reference.
| Property | Typical | Imperial | Common spec. minimum |
|---|---|---|---|
| Tensile strength, Rm | 750 MPa | 109 ksi | 650 MPa |
| Proof stress 0.2%, Rp0.2 | 275 MPa | 40 ksi | 240 MPa |
| Elongation at break, A | 42 % | 42 % | 25 % |
| Reduction of area, Z | 50 % | 50 % | 30 % |
| Modulus of elasticity, E | 206 GPa | 29.9 × 10³ ksi | — |
| Hardness | ≤ 230 HB | ≤ 230 HB | ≤ 230 HB |
Physical properties
The density of UNS N06075 is 8.37 g/cm³ (0.302 lb/in³). This figure converts a drawing volume into forging weight, so it is the number most often needed at the quotation stage.
| Property | Value | Imperial |
|---|---|---|
| Density | 8.37 g/cm³ | 0.302 lb/in³ |
| Melting range (approx.) | 1340–1380 °C | 2440–2515 °F |
| Modulus of elasticity | 206 GPa | 29.9 × 10³ ksi |
| Magnetic response | Non-magnetic (austenitic) in the annealed condition | |
| Crystal structure | Face-centred cubic gamma austenite with dispersed MC carbides | |
Coefficient of thermal expansion, thermal conductivity and specific heat all vary with temperature. Request the full temperature-dependent property set from sales@steelforgepieces.com if it is needed for a thermal-stress calculation.
Service temperature envelope
UNS N06075 has two temperature limits and they are frequently confused on drawings. The strength limit is about 815 °C (1500 °F), beyond which tensile and creep-rupture properties fall away quickly. The oxidation limit is about 1100 °C, the point at which the protective chromia scale stops adhering. A lightly loaded part can sit at 1000 °C for a long time. A heavily loaded one can fail at 850 °C.
Melting, forging route and heat treatment
Melting route
UNS N06075 forging stock is produced by EAF melting with VOD refining followed by an ESR remelt, giving a double-melted ingot with low residual gas and controlled inclusion content. VIM + ESR or VIM + VAR routes can be arranged where an aerospace specification calls for them.
Hot forging
UNS N06075 is hot forged in the range 982–1204 °C (1800–2200 °F). Jiangyin Jiangnan Metal Co., Ltd. starts at 1150–1180 °C and finishes above 1000 °C, reheating as required so that the final reduction is taken hot enough to recrystallise fully but cool enough to avoid grain coarsening. Finishing below about 950 °C risks edge cracking. Finishing too hot leaves a coarse grain that will not pass a fine-grain ultrasonic acceptance class.
Solution annealing
| Operation | Temperature | Soak | Cooling |
|---|---|---|---|
| Hot forging | 982–1204 °C | To section | Air |
| Solution anneal, bar and heavy forgings | 1050 °C (1920 °F) | 30–60 min | Air cool |
| Solution anneal, thin sections | 1050 °C (1920 °F) | 5–10 min | Air cool |
| Age hardening | Not applicable, UNS N06075 is not age hardenable | ||
| Stress relief after welding | Not normally required, consider only for severe corrosive service | ||
Welding and machining
UNS N06075 welds readily by MMA, TIG, MIG and submerged-arc processes, and should be in the annealed condition before welding. Post-weld heat treatment is not normally required. For machining, treat it as a work-hardening austenitic material: rigid setup, positive rake geometry, low surface speed, heavy positive feed to stay under the hardened layer, and flood coolant.
UNS N06075 forged product forms and size range
Jiangyin Jiangnan Metal Co., Ltd. produces UNS N06075 as open-die forgings and seamless rolled rings made to drawing. There is no fixed size catalogue. Each piece is forged to the customer's dimensions with an agreed machining allowance.
| Product form | Size range | Typical use |
|---|---|---|
| Seamless rolled rings | OD 200–4000 mm | Turbine casings, retaining rings, flange blanks |
| Forged rings and sleeves | OD 100–2000 mm | Bushings, spacers, wear sleeves |
| Round bars | Ø 50–800 mm | Machining stock, fastener blanks, stems |
| Discs and blanks | Ø 150–2500 mm | Turbine discs, blind flanges, tube sheets |
| Shafts and spindles | Length to 8000 mm | Drive shafts, eccentric shafts, rolls |
| Flanges | To DN 1500 or drawing | Pressure vessels, heat exchangers, piping |
| Hollow and step forgings | To drawing | Valve bodies, nozzles, manifolds |
| Unit weight | 20 kg – 20 000 kg | Single-piece forging weight |
| Minimum order | 1 piece | Prototype and single-item orders accepted |
| Typical lead time | 25–45 days | From drawing approval, subject to stock and NDT scope |
Delivery conditions available: as-forged, rough machined, solution annealed, pickled, shot blasted, or finish machined to drawing. State the required condition on the enquiry so that forging weight and allowance are quoted correctly.
Applications of UNS N06075 forgings by industry
| Industry | Typical forged components |
|---|---|
| Gas and steam turbines | Seamless rolled rings, casings, shroud rings, turbine shafts, spacers, ancillary hardware |
| Industrial furnaces and heat treatment | Furnace internals, retort components, fixtures, muffle supports, roller trunnions |
| Pressure vessels and heat exchangers | Forged flanges, forged tube sheets, forged tubes and pipes, shell courses, air receivers |
| Valves | Valve bodies, stems, valve seat rings, blocks and bonnets for ball, gate, globe, check and plug valves |
| Oil and gas, offshore | Subsea and deepwater production hardware, wellhead components, Christmas-tree parts, bushings and sleeves |
| Nuclear | Boiler tube supports, structural hardware outside the pressure boundary, core internals fixtures |
| Process plant | Columns and towers, tanks, silos, preheaters, crystalliser equipment, process modules |
| Power transmission | Forged gears, spindles, rolls, gearbox shafts, compressor components |
| Automotive and general | Exhaust-valve components, die-casting inserts and cores, forged wheels, manifolds |
Jiangyin Jiangnan Metal Co., Ltd. supplies UNS N06075 open-die forging parts into all of the sectors above, forging to drawing rather than to a fixed catalogue.
Testing, non-destructive examination and certification
Every UNS N06075 forging leaving the Jiangyin factory is ultrasonically tested and delivered with a mill test certificate. Name the acceptance class on the purchase order, since the forging reduction and heat-treatment plan are set from it.
| Scope | Standard or method |
|---|---|
| Ultrasonic testing (UT) | EN 10228-3 · SEP 1921 · ASTM A388 |
| Liquid penetrant (PT) | ASTM E165 · EN ISO 3452 |
| Chemical analysis | Ladle and product analysis, spectrometric |
| Mechanical testing | Tensile and hardness; impact and elevated-temperature tensile on request |
| Grain size and microstructure | ASTM E112 on request |
| Certification | EN 10204 3.1 |
| Third-party certification | EN 10204 3.2 |
| Inspection agencies | TÜV, SGS, BV, Lloyd's Register and customer witness inspection accepted |
UNS N06075 compared with adjacent grades
Two specification errors come up repeatedly. One is calling for UNS N06075 where the duty actually needs an age-hardenable alloy. The other is paying superalloy prices for service below 550 °C, where a stabilised stainless would do the job. The table below covers both.
| Grade | Strengthening | Typical Rp0.2 | Choose it when |
|---|---|---|---|
| UNS N06075 (Nimonic 75) | Solid solution plus MC carbides | 275 MPa | Oxidation resistance, weldability and formability matter more than strength |
| Nimonic 80A (N07080) | Gamma-prime precipitation, Al plus Ti | ~600 MPa | Same environment but sustained load above 700 °C |
| Inconel 601 (N06601) | Solid solution plus Al | ~300 MPa | Cyclic oxidation and carburisation resistance is the priority |
| Incoloy 800H (N08810) | Solid solution, Fe-Ni-Cr | ~170 MPa | Long-term creep service where a lower alloy cost is acceptable |
| Hastelloy X (N06002) | Solid solution plus Mo | ~350 MPa | Combustion-zone strength and fabricability to 1200 °C |
| Stainless 321 / 347 | Stabilised austenitic | ~205 MPa | Service stays below 550 °C, far more cost-effective there |
How to order UNS N06075 forgings
- Send the drawing or size. Email the drawing, rough size or finished dimensions to sales@steelforgepieces.com, stating grade UNS N06075 or Nimonic 75, quantity and required delivery condition.
- Receive the quotation. Jiangyin Jiangnan Metal returns forging weight, machining allowance, heat-treatment plan, NDT scope and lead time, normally within 24 hours.
- Approve the manufacturing plan. Confirm melting route, forging ratio, solution annealing parameters, ultrasonic acceptance class and certification level: EN 10204 3.1, or 3.2 with third-party inspection.
- Production and delivery. The forgings are produced, heat treated, tested and shipped with the mill test certificate. Witness inspection can be arranged before release.
Frequently asked questions about UNS N06075
What is UNS N06075?
UNS N06075 is a solution-strengthened 80/20 nickel-chromium superalloy with controlled additions of titanium and carbon. It contains 18–21% chromium, 0.2–0.6% titanium and 0.08–0.15% carbon with nickel as the balance. UNS N06075 is used where oxidation and scaling resistance up to about 1100 °C is needed together with moderate strength and good weldability. Jiangyin Jiangnan Metal Co., Ltd. forges UNS N06075 into rings, bars, discs, shafts and flanges at its factory in Jiangyin, Jiangsu, China.
Is UNS N06075 the same as Nimonic 75?
Yes. UNS N06075 is the Unified Numbering System designation for the alloy sold commercially as Nimonic 75, Alloy 75 or Nickel Alloy 75. The same material appears as W.Nr. 2.4951 and 2.4630 in German specifications, NiCr20Ti in DIN and ISO, NC20T in AFNOR, and BS HR5, HR203, HR403 and HR504 in British specifications. Composition limits differ slightly between these specifications, so the purchase order should state the governing specification.
What is the chemical composition of UNS N06075?
UNS N06075 contains chromium 18.0–21.0%, titanium 0.20–0.60%, carbon 0.08–0.15%, iron 5.0% maximum, silicon 1.0% maximum, manganese 1.0% maximum, copper 0.50% maximum and aluminium 0.30% maximum, with nickel as the balance, all by weight percent.
What is the maximum service temperature of UNS N06075?
UNS N06075 holds useful tensile and creep-rupture strength to about 815 °C (1500 °F) and resists oxidation and scaling in air to about 1100 °C under low stress. For sustained structural loading the practical ceiling is nearer 650 °C. Above 815 °C under continuous stress, precipitation-hardened grades such as Nimonic 80A, Waspaloy or Inconel X-750 are normally specified instead.
What is the difference between Nimonic 75 (N06075) and Nimonic 80A (N07080)?
Nimonic 75 (UNS N06075) is solution-strengthened only and cannot be age hardened, which gives it good formability and weldability but moderate high-temperature strength. Nimonic 80A (UNS N07080) adds about 1.0–1.8% aluminium and 1.8–2.7% titanium to precipitate a gamma-prime phase, roughly doubling the room-temperature yield strength and extending useful strength above 815 °C. Nimonic 75 suits oxidation resistance, welded fabrications and low to moderate stress. Nimonic 80A suits higher stressed turbine hardware.
Can UNS N06075 forgings be welded?
Yes. UNS N06075 welds readily by MMA, TIG, MIG and submerged-arc processes. The material should be in the solution annealed condition before welding. Post-weld heat treatment is not normally required unless the service environment is severely corrosive, in which case a stress relief is advisable.
Which forged product forms are available in UNS N06075?
Jiangyin Jiangnan Metal Co., Ltd. supplies UNS N06075 as seamless rolled rings, forged rings, round and profiled bars, discs, blanks, shafts, spindles, sleeves, bushings, flanges, tube sheets, hollow forgings, valve bodies, valve seat rings, nozzles and custom open-die shapes made to drawing.
Which standards cover UNS N06075 forgings?
UNS N06075 forgings are commonly ordered to BS HR5 or HR504 for bar, BS HR203 for sheet and plate, BS HR403 for tube, MSRR 7004 and 7104 for aerospace, DIN 17742 and DIN 17750–17752, and ISO 9723–9725. Ultrasonic testing is normally performed to EN 10228-3, SEP 1921 or ASTM A388, and material is certified to EN 10204 3.1 or 3.2. ASTM B637 does not cover N06075; it applies to precipitation-hardening nickel alloys.
Who manufactures UNS N06075 open-die forgings in China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, that manufactures UNS N06075 (Nimonic 75) forgings to customer drawings. The company can be reached on +86-189-2135-9659 or at sales@steelforgepieces.com, and supplies EN 10204 3.1 and 3.2 certified material worldwide.
What certification is supplied with UNS N06075 forgings?
Every UNS N06075 forging is delivered with a mill test certificate to EN 10204 3.1, covering heat number, ladle and product analysis, mechanical test results, heat-treatment record and NDT report. EN 10204 3.2 certification with third-party inspection by an agency such as TÜV, SGS, BV or Lloyd's can be arranged when specified on the purchase order.
What is the density of UNS N06075?
The density of UNS N06075 is 8.37 g/cm³ (0.302 lb/in³) at room temperature. This value converts a drawing volume into forging weight when quoting.
How is UNS N06075 heat treated after forging?
UNS N06075 is solution annealed at 1050 °C (1920 °F) followed by air cooling. Bar and heavy forged sections are held 30–60 minutes at temperature; thin sections are held 5–10 minutes. The alloy is not age hardenable, so no precipitation treatment follows.
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About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory, Jiangyin, China
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory located at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The company forges nickel-based superalloys including UNS N06075 (Nimonic 75), together with carbon steel, alloy steel, tool steel and stainless steel, into seamless rolled rings, forged rings, bars, discs, shafts, sleeves, bushings, flanges and tube sheets made to customer drawings.
All UNS N06075 forgings are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 and supplied with an EN 10204 3.1 mill test certificate. EN 10204 3.2 certification with third-party inspection is available on request. Enquiries with a drawing or size are quoted within 24 hours.
Company
Jiangyin Jiangnan Metal Co., Ltd.
Factory address
No.1 Chengxiqiao Road, Zhouzhuang Town,
Jiangyin City, Jiangsu Province, ChinaTelephone / WhatsApp
Email
Website
Business
Open-die forgings and seamless rolled rings