Nickel-base superalloy / Open-die forgings
NiCr20Co18Ti Forgings Nimonic 90 · UNS N07090 · W.Nr. 2.4632 / 2.4969 · BS HR2 · AMS 5829 · GH4090
- Rings and seamless rolled rings
- Discs
- Shafts
- Flanges
- Round bars
- Sleeves and bushings
- Tube sheets
- Valve bodies
NiCr20Co18Ti is the EN/DIN chemical designation for a precipitation-hardenable wrought nickel-chromium-cobalt superalloy, also known by the trade name Nimonic 90 and listed as UNS N07090, Werkstoff 2.4632, BS HR2, AMS 5829 and Chinese GH4090. Titanium and aluminium additions form gamma prime precipitates that give the alloy stress-rupture strength and creep resistance to approximately 920 °C (1688 °F).
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu Province, China, produces NiCr20Co18Ti as forged rings, seamless rolled rings, discs, shafts, flanges, round bars, sleeves, bushings and tube sheets to customer drawings, delivered to DIN 17744 with EN 10204 3.1 or 3.2 inspection certificates.
- UNS
- N07090
- Werkstoff
- 2.4632 / 2.4969
- Delivery standard
- DIN 17744
- Alloy type
- Ni-Cr-Co, age hardening
- Creep service to
- 920 °C / 1688 °F
- Density
- 8.18 g/cm³
- Melting route
- EAF + VOD + ESR
- Certificate
- EN 10204 3.1 / 3.2
Figures on this page are for engineering guidance. The binding values for any delivery are those stated on the mill test certificate issued with that heat.
What NiCr20Co18Ti is
NiCr20Co18Ti is a wrought nickel-chromium-cobalt superalloy hardened by precipitation of the gamma prime phase Ni3(Al,Ti). The precipitate forms during ageing and remains coherent with the nickel matrix at elevated temperature, which is the source of the creep strength.
The alloy is normally specified for one of three reasons:
- Creep and stress-rupture life. Rated creep-resisting service temperature is approximately 920 °C (1688 °F). Where tensile strength rather than creep life governs, the working limit is around 704 °C (1300 °F).
- Oxidation and hot corrosion resistance. Chromium at 18 to 21 % forms a protective Cr2O3 scale, giving resistance in oxidising combustion atmospheres and in sulphur-bearing hot gas.
- Forgeability. The alloy can be open-die forged and ring rolled, so forged rings, discs and shafts are a practical route to near-net shapes.
NiCr20Co18Ti is a high-temperature strength alloy, not a wet-corrosion alloy. For acid or chloride service, a Ni-Mo-Cr grade is the appropriate choice. See the nickel alloy index for alternatives.
Equivalent designations and standards
The same alloy is listed under a number of names. State on the purchase order which designation the mill certificate must carry. End users frequently check the certificate against the exact designation written in their own drawing.
| System or country | Designation | Typical scope |
|---|---|---|
| EN / DIN chemical name | NiCr20Co18Ti | DIN 17744, EN 10302 |
| EN / DIN material number | 2.4632 (also 2.4969) | Bar, forging stock, forgings |
| USA, UNS | N07090 | All wrought forms |
| USA, aerospace | AMS 5829 | Bar, forgings, forging stock |
| UK, BS | HR2, HR202, HR402, HR501 to HR503, BS 3075 NA19 | Bar, sheet, tube, wire by form |
| UK, Rolls-Royce | MSRR 7137, MSRR 7017 | Aero-engine material |
| France | NCK20TA (AIR 9165) | Aerospace |
| China, GB | GH4090 (GH90) | High-temperature alloy |
| ISO | NiCr20Co18Ti3 | Wrought nickel alloys |
| Trade names | Nimonic 90, Alloy 90, Nicrofer 7520Ti, Pyromet 90, Nickelvac 90 | Producer-specific |
Nimonic is a registered trade mark of the Special Metals group of companies. Jiangyin Jiangnan Metal Co., Ltd. is not affiliated with that group. The trade name is quoted here only as a cross-reference to the generic alloy NiCr20Co18Ti / UNS N07090.
Chemical composition of NiCr20Co18Ti
Composition limits below are those Jiangyin Jiangnan Metal Co., Ltd. delivers to, per DIN 17744. Values are mass fractions in percent. The ladle analysis for the actual heat is reported on the mill certificate.
| Limit | C | Ni | Cr | Co | Ti | Al | Fe | Mn | Si | Cu | P | S | Zr |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| min | – | Bal. | 18.0 | 15.0 | 2.0 | 1.0 | – | – | – | – | – | – | – |
| max | 0.13 | Bal. | 21.0 | 21.0 | 3.0 | 2.0 | 1.5 | 1.0 | 1.0 | 0.20 | 0.020 | 0.015 | 0.15 |
Nickel is the balance. Titanium and aluminium together control the gamma prime volume fraction and therefore the achievable strength. Cobalt raises the gamma prime solvus and slows coarsening at temperature.
Mechanical properties
Room-temperature properties depend on the heat treatment condition ordered. State the condition explicitly. A solution-treated forging and a solution-treated plus aged forging from the same heat give very different values.
| Condition | Tensile strength Rm | Yield Rp0.2 | Elongation A | Basis |
|---|---|---|---|---|
| Solution treated | ≥ 820 MPa | ≥ 590 MPa | – | Specified minimum, DIN 17744 |
| Solution treated and aged | approx. 1200 MPa | approx. 800 MPa | approx. 20 % | Typical published value for bar and forgings |
The first row is a specified minimum. The second row gives typical published values for hardened bar and forgings and is indicative only, not a guaranteed property. Section thickness, forging reduction and the ageing cycle all affect these figures. Guaranteed values are agreed at order stage and reported on the certificate.
Behaviour at temperature
NiCr20Co18Ti retains useful tensile strength to about 704 °C (1300 °F) and is rated for creep-resisting and stress-rupture duty to about 920 °C (1688 °F). Above that range, oxidation and gamma prime coarsening limit the service life and a different alloy class is required. Where the design code requires creep-rupture allowables for a stated life at a stated stress, send the requirement with the enquiry so that the correct condition and testing can be quoted.
Physical properties
Nominal values used for weight calculation, thermal design and fixture allowance.
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.18 g/cm³ | 0.296 lb/in³ |
| Melting range, approx. | 1310 to 1370 °C | 2390 to 2500 °F |
| Modulus of elasticity | approx. 220 GPa | approx. 32 x 106 psi |
| Thermal conductivity | approx. 11.5 W/(m·K) | approx. 6.6 Btu/(hr·ft·°F) |
| Mean coefficient of expansion | approx. 12.8 µm/(m·K) | approx. 7.1 µin/(in·°F) |
| Specific heat capacity | approx. 410 J/(kg·K) | approx. 0.098 Btu/(lb·°F) |
| Magnetic response | Essentially non-magnetic in the solution treated condition | |
Use 8.18 g/cm³ to convert a machined part volume into a forged weight, then add the machining allowance agreed for the shape. Jiangyin Jiangnan Metal returns a forged weight with every quotation so the buyer can check the calculation.
Melting route, hot working and heat treatment
Melting
NiCr20Co18Ti forging stock supplied by Jiangyin Jiangnan Metal Co., Ltd. is melted by EAF plus VOD followed by electroslag remelting (ESR). The remelting step refines the solidification structure and reduces non-metallic inclusions, which is what makes the tighter ultrasonic acceptance classes achievable on heavy ring and disc sections. Vacuum induction melting followed by ESR or VAR can be arranged where an aerospace specification requires it.
Hot working
The alloy is open-die forged and ring rolled in the range 1050 to 1200 °C, with reheating as required and finishing controlled so that recrystallisation is complete without grain coarsening. It work hardens quickly, so reductions are planned per pass.
Heat treatment
| Step | Temperature | Time | Cooling |
|---|---|---|---|
| Solution treatment | 1080 °C / 1975 °F | 8 h | Air cool |
| Precipitation ageing | 700 °C / 1290 °F | 16 h | Air cool |
This cycle is applied unless the order specifies otherwise. Sheet, strip and some aerospace specifications use different solution and stabilisation stages. State the governing specification if a different cycle is required.
Machining and welding
NiCr20Co18Ti work hardens rapidly. Machine with rigid setups, sharp positive-rake tooling, low surface speed with a heavy positive feed, and flood coolant. Rough machining is easier before ageing. The alloy is joined by TIG, MIG, shielded metal arc and resistance welding, and by electron beam, friction and flash butt methods. Where full strength is required across the joint, solution treat and re-age after welding.
NiCr20Co18Ti forged product forms and size range
All forms are made to the customer drawing on open-die presses and ring rolling mills. Send a drawing or a size list and a forged weight is returned with the price.
| Form | Size range | Typical use |
|---|---|---|
| Seamless rolled rings | OD 200 to 3000 mm, wall 20 to 400 mm, height 20 to 800 mm | Turbine ring sections, casing rings, bearing rings |
| Forged rings, open-die | OD 100 to 1500 mm | Short-run rings, spacer rings, seat rings |
| Discs and blanks | OD 100 to 1500 mm, thickness 20 to 500 mm | Turbine discs, valve discs, blade blanks |
| Shafts, spindles, stems | Dia. 50 to 800 mm, length up to 6000 mm | Rotor shafts, valve stems, eccentric shafts |
| Round bar and forging stock | Dia. 20 to 600 mm | Feedstock for machining and further forging |
| Flanges | To drawing, or to ASME B16.5 / EN 1092-1 pattern | High-temperature pipework, vessel nozzles |
| Sleeves and bushings | OD 80 to 1200 mm | Hot-working tooling, wear sleeves |
| Tube sheets | To drawing | Shell-and-tube heat exchangers, preheaters |
| Blocks, bodies, valve parts | To drawing | Valve bodies, seat rings, manifolds, nozzles |
| Single-piece forged weight | 5 to 2000 kg | – |
Sizes above are the working envelope for this alloy class and are confirmed case by case against press capacity, forging ratio and the required ultrasonic class. Larger or heavier parts are quoted on request.
Delivery condition options
- As forged
- Solution treated
- Solution treated and aged, the usual supply condition
- Rough machined to a proof-machining envelope for ultrasonic testing
- Finish machined to drawing
Applications for NiCr20Co18Ti forgings
The alloy is used where load has to be carried for a long service life at a temperature that would cause a stainless steel to relax.
Gas turbines and power generation
Turbine discs, blade and vane blanks, ring sections, spacers, rotor shafts, and gearbox and compressor components. Seamless rolled rings are used here because ring rolling produces a circumferential grain flow aligned with the hoop stress.
Hot-working tooling and heat-treatment equipment
Die casting inserts and cores, hot-working tool bodies, furnace fixtures and retorts, boiler tube supports, and high-temperature springs and fasteners.
Valves and flow control
Forged valve bodies, seat rings, stems, discs, plugs and blocks for ball, gate, globe, check and plug valves in hot service, and strainer bodies.
Pressure equipment and process plant
Forged flanges, tube sheets, nozzles, pipes and tubes for pressure vessels, shell-and-tube heat exchangers, columns and towers, preheaters, silos and process modules.
Oil, gas and offshore
Bushings, sleeves, discs and forged bodies for subsea and deepwater production systems, wellhead and Christmas-tree components, industrial air compressors, power generators and nitrogen generators.
Automotive and nuclear
Exhaust valves, turbocharger components, forged crankshafts for high-duty engines, and nuclear plant components where creep resistance and a documented material pedigree are both required.
Testing, inspection and certification
Every NiCr20Co18Ti forging leaves the works with a documented pedigree. Specify the standard and acceptance class on the purchase order. If none is stated, the works default applies.
| Check | Standard or method |
|---|---|
| Chemical analysis | Ladle analysis reported per heat, product analysis on request |
| Ultrasonic testing | EN 10228-3, SEP 1921, ASTM A388 |
| Surface examination | Dye penetrant on request |
| Mechanical testing | Tensile and hardness, impact and elevated-temperature tests on request |
| Heat treatment record | Furnace chart supplied with the certificate |
| Dimensional inspection | Against the approved forging drawing |
| Inspection certificate | EN 10204 3.1 (works) or EN 10204 3.2 (third party) |
| Third party witnessing | TUV, SGS, BV, Lloyd's Register, or the buyer's own inspector |
An EN 10204 3.2 certificate must be agreed before production starts, because the inspection body has to witness the tests as they are carried out. It cannot be added afterwards.
How to order NiCr20Co18Ti forgings
An enquiry containing these five items can normally be priced within one working day.
- Drawing or dimensions. PDF, STEP or DWG. For rings give OD x ID x height, for discs OD x thickness, for bars diameter x length. State the quantity.
- Grade and standard as it must appear on the certificate, for example NiCr20Co18Ti to DIN 17744, Nimonic 90 to AMS 5829, or UNS N07090 to BS HR2.
- Delivery condition: as forged, solution treated, or solution treated and aged.
- Testing and acceptance class: the ultrasonic standard (EN 10228-3, SEP 1921 or ASTM A388) and the class, plus any dye penetrant, impact or elevated-temperature testing.
- Certificate type: EN 10204 3.1 or 3.2, and the inspection body if 3.2.
Send it to sales@steelforgepieces.com or call +86-189-2135-9659. Drawings are treated as confidential and a non-disclosure agreement can be signed before quotation.
Frequently asked questions about NiCr20Co18Ti
What is NiCr20Co18Ti?
NiCr20Co18Ti is the EN/DIN chemical designation for a precipitation-hardenable wrought nickel-chromium-cobalt superalloy strengthened by titanium and aluminium additions. It contains 18 to 21 % chromium, 15 to 21 % cobalt, 2 to 3 % titanium and 1 to 2 % aluminium with nickel as the balance, and it retains stress-rupture strength and creep resistance to about 920 °C (1688 °F). Jiangyin Jiangnan Metal Co., Ltd. supplies it as open-die forgings.
Is NiCr20Co18Ti the same as Nimonic 90?
Yes. NiCr20Co18Ti and Nimonic 90 are the same alloy under different naming systems. NiCr20Co18Ti is the European chemical designation, Nimonic 90 is the trade name originally registered by the Special Metals group, and the same material is also listed as UNS N07090, Werkstoff 2.4632 (or 2.4969), BS HR2, AMS 5829 and Chinese GH4090. A single heat can be certified to more than one designation if its chemistry and testing satisfy each specification.
What is the UNS number for NiCr20Co18Ti?
The UNS number is N07090. The European material numbers are 2.4632 and 2.4969, the British specifications are BS HR2, HR202, HR402 and HR501 to HR503, the American aerospace specification for bar and forging stock is AMS 5829, and the Chinese designation is GH4090.
What is the maximum service temperature of NiCr20Co18Ti?
NiCr20Co18Ti is normally rated for creep-resisting and stress-rupture service to approximately 920 °C (1688 °F). Where high tensile strength rather than creep life governs, the usual working limit is about 704 °C (1300 °F). The allowable temperature for a given part depends on stress, required life and the design code applied.
What is the chemical composition of NiCr20Co18Ti?
To DIN 17744: carbon 0.13 % max, nickel balance, chromium 18.0 to 21.0 %, manganese 1.0 % max, phosphorus 0.02 % max, sulphur 0.015 % max, silicon 1.0 % max, iron 1.5 % max, copper 0.2 % max, cobalt 15.0 to 21.0 %, aluminium 1.0 to 2.0 %, titanium 2.0 to 3.0 %, zirconium 0.15 % max.
What heat treatment is used for NiCr20Co18Ti forgings?
The standard bar and forging cycle is solution treatment at 1080 °C (1975 °F) for 8 hours with air cooling, followed by precipitation ageing at 700 °C (1290 °F) for 16 hours with air cooling. This is the cycle Jiangyin Jiangnan Metal Co., Ltd. applies unless the customer specifies an alternative condition.
What is the difference between Werkstoff 2.4632 and 2.4969?
There is no difference in the alloy. 2.4632 and 2.4969 are two material numbers listed for the same nickel-chromium-cobalt alloy NiCr20Co18Ti, also known as Nimonic 90 and UNS N07090. Buyers should state which number the mill test certificate must show, because some end users check the certificate against the number written in their own drawing.
Which melting route is used for NiCr20Co18Ti forging stock?
Jiangyin Jiangnan Metal Co., Ltd. supplies NiCr20Co18Ti forgings made from material melted by electric arc furnace plus vacuum oxygen decarburisation and electroslag remelting (EAF + VOD + ESR). The remelting step reduces segregation and non-metallic inclusions, which matters for the ultrasonic acceptance classes normally applied to superalloy rings and discs.
Can NiCr20Co18Ti be made into seamless rolled rings?
Yes. NiCr20Co18Ti is a wrought alloy and is routinely ring rolled. Jiangyin Jiangnan Metal Co., Ltd. produces NiCr20Co18Ti seamless rolled rings alongside open-die forged discs, shafts, flanges, sleeves, bushings and tube sheets. Ring rolling produces a circumferential grain flow, which is why rolled rings are specified in place of parts cut from plate for rotating and pressure-retaining duty.
What non-destructive testing is performed on NiCr20Co18Ti forgings?
Forgings are ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388, to the quality class stated on the order. Dye penetrant examination, hardness survey, mechanical testing and dimensional inspection can be added, and any test can be witnessed by a third party inspection body.
Which certificate is supplied with NiCr20Co18Ti forgings?
Forgings are released with an EN 10204 3.1 inspection certificate issued by the works, or an EN 10204 3.2 certificate countersigned by an independent third party such as TUV, SGS, BV or Lloyd's Register when the order requires it. The certificate reports the heat number, ladle analysis, heat treatment record, mechanical test results and the ultrasonic testing result.
What is the density of NiCr20Co18Ti?
The density of NiCr20Co18Ti is approximately 8.18 g/cm³ (0.296 lb/in³). This figure is used to convert a machined part volume into a forged weight when preparing a quotation, together with the machining allowance agreed for the shape.
What is NiCr20Co18Ti used for?
Gas turbine discs, blades, ring sections and rotor components, hot-working tools and die inserts, high-temperature springs and fasteners, automobile exhaust valves, furnace and heat-treatment fixtures, boiler tube supports, and valve bodies, seat rings and stems for high-temperature service. It also appears in offshore, nuclear and power generation equipment where creep resistance above 700 °C is required.
How is NiCr20Co18Ti machined and welded?
The alloy work hardens rapidly, so machining uses rigid setups, positive-rake tooling, low surface speed with a heavy positive feed and generous coolant. Rough machining is easier in the solution treated condition before ageing. It is welded by TIG, MIG, shielded metal arc and resistance methods, and post-weld solution treatment plus ageing is advisable where full strength is required across the joint.
Who supplies NiCr20Co18Ti 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, producing NiCr20Co18Ti (Nimonic 90 / UNS N07090 / W.Nr. 2.4632) forged rings, seamless rolled rings, discs, shafts, flanges, bars, sleeves, bushings and tube sheets to customer drawings. Enquiries: +86-189-2135-9659, sales@steelforgepieces.com, www.steelforgepieces.com.
About the supplier
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. The works produces forged rings, seamless rolled rings, discs, shafts, flanges, sleeves, bushings, tube sheets and valve components in carbon steel, alloy steel, tool steel, stainless steel and nickel-base superalloys, all to customer drawings.
This page is maintained by the company's engineering and sales team and is reviewed when a governing standard changes or when new production data becomes available.
Jiangyin Jiangnan Metal Co., Ltd.Open-Die Forging Factory
No.1 Chengxiqiao Road, Zhouzhuang Town,
Jiangyin City, Jiangsu Province, China
Tel: +86-189-2135-9659
Email: sales@steelforgepieces.com
Web: www.steelforgepieces.com
Cite this page
Reference for use in a specification, report or technical bibliography:
Jiangyin Jiangnan Metal Co., Ltd. (2026). "NiCr20Co18Ti Forgings (Nimonic 90 / UNS N07090 / W.Nr. 2.4632)." steelforgepieces.com. https://www.steelforgepieces.com/Nickel-Alloy/NiCr20Co18Ti.html. Last updated 24 August 2026.
Technical disclaimer. Data on this page is compiled from published standards and general engineering practice and is offered for guidance only. It does not constitute a warranty, express or implied, and it is not a substitute for the governing specification or for design calculation. Properties vary with section size, forging reduction and heat treatment. The binding values for any delivery are those stated on the mill test certificate issued for that heat. Nimonic, Inconel, Incoloy, Hastelloy, Haynes, Waspaloy, Udimet and Rene are trade marks of their respective owners and are used here as cross-references to generic alloy designations.