2.4632 (NiCr20Co18Ti / UNS N07090 / DIN 2.4969), also identified by the trade name Nimonic® Alloy 90, is a precipitation-hardenable nickel-chromium-cobalt superalloy. Maximum service temperature: 920°C. Minimum tensile strength (precipitation-hardened, EN 10302:2008): 1,100 MPa. Density: 8.18 g/cm³. Applications: gas turbine blades, turbine discs, valve seats, and seamless rolled rings.
What Is 2.4632 (NiCr20Co18Ti)?
2.4632 is the DIN/EN material number for a precipitation-hardenable nickel-chromium-cobalt superalloy. Its ISO chemical designation NiCr20Co18Ti directly describes its three dominant alloying elements: approximately 20% chromium, 18% cobalt, and a controlled titanium addition — balanced in a nickel matrix that constitutes 49–64% of the alloy by weight per EN 10302:2008.
Originally developed in the mid-twentieth century for early jet engine applications, this alloy became a workhorse of gas turbine engineering and remains a primary material choice wherever service temperatures fall between 750°C and 920°C and both creep resistance and oxidation resistance are simultaneously required.
Both 2.4632 and 2.4969 refer to the same NiCr20Co18Ti chemical composition. The 2.4969 designation applies specifically to the seamless rolled ring and tube product form under certain DIN/EN standards, while 2.4632 is the general designation for bar, disc, and open-die forging stock. Always specify the correct designation on engineering drawings to ensure the MTC references the right product-form standard.
International Standards & Cross-Reference Designations
Different national standards bodies assign different designations to the same alloy. The table below provides the definitive cross-reference for global procurement, certification, and engineering documentation.
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| Standard Body | Designation | Country / Region | Typical Application |
|---|---|---|---|
| DIN / EN | 2.4632 / 2.4969 | Germany / Europe | Forgings, rings (EN 10302:2008) |
| UNS | N07090 | USA | All product forms |
| Trade name* | Nimonic® Alloy 90 | International | Commercial identification |
| AMS | AMS 5829 / AMS 5830 | USA (Aerospace) | Bars, billets, rings |
| BS | HR401 / HR2 | United Kingdom | Sheet, bar, forging |
| AFNOR | NC20K14 | France | General industrial |
| ISO | NiCr20Co18Ti (ISO 9723) | International | Bars and forgings |
| Chemical formula | NiCr20Co18Ti | — | Compositional shorthand |
* Nimonic® is a registered trademark of Special Metals Corporation. All other designations above are standardised material numbers or chemical formulas in the public domain.
When writing an RFQ or purchase order, always state which standard the Mill Test Certificate (MTC) must be certified to — for example: "2.4632 per EN 10302:2008, MTC to EN 10204 3.1". Each standard carries different chemical and mechanical test requirements. Include your end-customer's required national equivalent (DIN 2.4632, AMS 5829, UNS N07090, etc.) so the manufacturer certifies to the correct standard.
Chemical Composition per EN 10302:2008
All Jiangsu Liangyi Co., Limited 2.4632 forgings are produced and certified to EN 10302:2008 — the primary European standard for creep-resisting steels, nickel alloys, and cobalt alloys in high-temperature service.
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| Element | Symbol | Min % | Max % | Role in alloy |
|---|---|---|---|---|
| Nickel | Ni | 49 | 64 | Austenitic matrix; base for γ phase |
| Chromium | Cr | 18 | 21 | Oxidation & hot corrosion resistance; M₂₃C₆ carbides |
| Cobalt | Co | 15 | 21 | Raises γ′ solvus; essential for creep life above 800°C |
| Titanium | Ti | 2.0 | 3.0 | Primary γ′ former: Ni₃(Al,Ti) |
| Aluminum | Al | 1.0 | 2.0 | Co-precipitates γ′; improves oxidation resistance |
| Iron | Fe | — | 1.5 | Tramp element (minimised) |
| Manganese | Mn | — | 1.0 | Deoxidiser |
| Silicon | Si | — | 1.0 | Deoxidiser; aids oxidation resistance |
| Carbon | C | — | 0.13 | Grain boundary carbides (MC, M₂₃C₆) |
| Zirconium | Zr | — | 0.15 | Grain boundary strengthener |
| Boron | B | — | 0.020 | Grain boundary cohesion; improves rupture life |
| Copper | Cu | — | 0.20 | Restricted — reduces hot workability |
| Phosphorus | P | — | 0.020 | Restricted — grain boundary embrittler |
| Sulfur | S | — | 0.015 | Restricted — hot-short cracking risk |
Major element distribution (nominal mid-range values):
Strengthening Mechanisms: Why 2.4632 Survives 920°C
1. γ′ Precipitation Hardening
The primary strengthening mechanism is the precipitation of ordered L1₂-structure γ′ phase — Ni₃(Al,Ti) — inside the face-centred cubic γ matrix. These coherent precipitates (typically 30–200 nm after optimum heat treatment) block dislocation movement because the anti-phase boundary (APB) energy required to shear them increases with temperature up to approximately 750°C — the "anomalous yield strength" effect. This is why 2.4632 retains useful strength at temperatures that would severely degrade precipitation-hardened stainless steels.
2. Solid-Solution Hardening by Cobalt and Chromium
The 15–21% cobalt content is the most distinctive feature of this alloy compared to simpler nickel-chromium alloys. Cobalt raises the γ′ solvus temperature, meaning the hardening phase remains stable for longer in high-temperature service. Chromium contributes solid-solution strengthening and M₂₃C₆ grain-boundary carbides that pin boundaries against sliding creep.
3. Grain Boundary Engineering
Trace additions of boron (≤0.020%) and zirconium (≤0.15%) segregate to grain boundaries and increase their cohesive energy, improving stress-rupture life and high-temperature ductility. Carbon controls carbide volume fraction: too little leaves boundaries unprotected; too much produces brittle continuous carbide films.
Cast 2.4632 / NiCr20Co18Ti often shows coarse, segregated microstructures with uncontrolled γ′ distribution. Hot forging followed by controlled two-stage heat treatment breaks down segregation, refines grain size, and produces a uniform γ′ distribution — which is why forged material consistently outperforms cast material in creep and fatigue testing, and why aerospace and power-generation specifications mandate forgings for critical rotating components.
To source bars, rings, discs, or custom open-die shapes that fully realise these metallurgical advantages, see the complete range of 2.4632 forged parts from Jiangsu Liangyi — covering product dimensions, available heat treatment conditions, and MTC options.
Physical Properties of 2.4632 (Precipitation-Hardened Condition)
These properties are required for thermal management calculations, resonance analysis, component weight estimation, and thermal expansion assessments.
Design note: At 11.47 W/(m·K) (20°C), 2.4632 conducts heat approximately 28% less efficiently than 316 stainless steel. Steeper thermal gradients during quenching must be accounted for in heat treatment fixture design and cooling rate calculations to avoid residual stress or quench cracking.
Room-Temperature Mechanical Properties
Tensile strength (Rm) ≥ 1,100 MPa · 0.2% proof strength (Rp₀.₂) ≥ 700 MPa · Elongation (A) ≥ 15%
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| Property | Symbol | Min Value | Unit | Condition |
|---|---|---|---|---|
| Tensile Strength | Rm | 1,100 | MPa | Precipitation hardened (+P) |
| 0.2% Proof Strength | Rp₀.₂ | 700 | MPa | Precipitation hardened (+P) |
| Elongation at Fracture | A | 15 | % | L₀ = 5.65√S₀ |
Typical actual values achieved in practice by quality-controlled forged 2.4632 are higher than the standard minimums: tensile strength approximately 1,250 MPa, proof stress approximately 830 MPa, and elongation approximately 22%. The gap between specification minimums and typical actuals gives designers a practical safety margin.
High-Temperature Mechanical Properties
At 800°C, 2.4632 retains a tensile strength of approximately 740 MPa — a level most austenitic stainless steels cannot sustain above 550°C.
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| Temperature | Tensile Strength (MPa) | 0.2% Proof Stress (MPa) | Elongation (%) |
|---|---|---|---|
| 20°C (room temp) | 1,250 | 830 | 22 |
| 400°C | 1,180 | 790 | 20 |
| 500°C | 1,140 | 770 | 18 |
| 600°C | 1,100 | 740 | 17 |
| 700°C | 1,020 | 700 | 16 |
| 800°C | 740 | 530 | 18 |
| 850°C | 530 | 400 | 20 |
| 900°C | 300 | 240 | 28 |
Industry data indicates that precipitation-hardened 2.4632 / NiCr20Co18Ti forgings typically achieve approximately 1,000-hour rupture life at 850°C and 154 MPa applied stress — a standard benchmark in gas turbine design. Engineers designing for service in the 850–920°C range should use 900°C tensile values as a conservative basis, since creep rather than ultimate tensile stress governs design at those temperatures.
Heat Treatment Specifications for 2.4632
Stage 1 — Solution anneal: 1080°C ± 10°C, 4–8 h, rapid cool (air or water quench, reach <600°C within 10 min). Stage 2 — Age: 700°C ± 10°C, minimum 16 h, air cool to room temperature. Both stages in controlled-atmosphere or vacuum furnace.
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| Stage | Temperature | Hold Time | Cooling | Purpose |
|---|---|---|---|---|
| 1 — Solution Annealing | 1080°C ± 10°C | 4–8 h (section dependent) | Rapid air cool or water quench; reach <600°C within 10 min | Dissolve coarse γ′; recrystallise forging; homogenise carbides |
| 2 — Precipitation Ageing | 700°C ± 10°C | 16 h minimum | Air cool to room temperature | Nucleate and grow coherent γ′ Ni₃(Al,Ti) precipitates to optimum 50–100 nm size |
Critical notes: The solution temperature must be high enough to fully dissolve coarse γ′ formed during forging but not so high that excessive grain growth occurs. The 16-hour minimum ageing hold is necessary to grow precipitates to the optimum coherent size that maximises the APB-pinning effect. Insufficient ageing time produces under-aged structures with sub-optimal proof stress.
Forging Temperature & Hot Working Guidelines
2.4632 is significantly more demanding to forge than carbon steel or austenitic stainless steel. Its flow stress at forging temperature is 2–3 times higher, requiring heavy-duty hydraulic presses and careful temperature monitoring.
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| Parameter | Value / Range | Rationale |
|---|---|---|
| Forging start temperature | 1100–1150°C | Below this range the alloy work-hardens rapidly and forging loads rise sharply |
| Min finish temperature | 950°C | Must remain above γ′ solvus; reheat if temperature drops below 950°C |
| Recommended die temperature | 200–350°C | Pre-heated dies reduce thermal shock, chilling, and surface cracking |
| Max reduction per heat | ~50% | Exceeding 60% risks adiabatic shear bands and internal cracking |
| Press type & capacity | Hydraulic; ≥2,000 t for billets >200 mm | Slow hydraulic pressing preferred over mechanical impact loading |
Jiangsu Liangyi Co., Limited operates 2,000–6,300 tonne hydraulic presses and 1–5 metre ring rolling machines, providing the controlled, slow-rate pressing essential for nickel superalloys. Slow hydraulic pressing allows deformation heat to dissipate uniformly and prevents adiabatic shear bands — a primary cause of internal cracking in Nimonic-equivalent alloy forgings.
For full details on weight range (30 kg to 30,000 kg), ring diameters up to 6 m, and available product forms, visit the 2.4632 forging capabilities and available product forms page.
Machining Guidelines for 2.4632 / NiCr20Co18Ti
2.4632 belongs to machinability group 4 — difficult to machine. The three key challenges are rapid tool wear from abrasive carbide particles, work hardening during cutting, and heat generation due to low thermal conductivity (11.47 W/(m·K)).
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| Operation | Tool material | Cutting speed | Feed rate | Coolant |
|---|---|---|---|---|
| Rough turning | PVD-coated carbide (K-grade) | 15–25 m/min | 0.20–0.35 mm/rev | Flood (soluble oil) |
| Finish turning | Fine-grain carbide (PVD-coated) | 20–35 m/min | 0.05–0.15 mm/rev | Flood |
| Rough milling | TiAlN-coated carbide end mills | 12–20 m/min | 0.04–0.08 mm/tooth | Flood |
| Drilling | Solid carbide (short flute) | 5–12 m/min | 0.02–0.06 mm/rev | High-pressure through-tool coolant |
| Grinding | CBN or soft-grade Al₂O₃ | 20–30 m/s | Fine dressing only | Heavy flood coolant |
1. Maintain continuous cutting contact. Interrupting the cut allows a work-hardened layer to form that destroys the next tool edge. 2. Use generous, consistent depth of cut rather than shallow repeated passes that plough the hardened surface layer. 3. Change cutting edges proactively — worn edges work-harden the surface ahead and accelerate failure of the following tool insert.
Welding Considerations
2.4632 / NiCr20Co18Ti is weldable with care but significantly more challenging than solid-solution nickel alloys. The primary risk is strain-age cracking (SAC).
What is strain-age cracking?
The precipitation-hardening response of 2.4632 makes it susceptible to SAC during post-weld heat treatment or in the heat-affected zone (HAZ) during welding of already precipitation-hardened base material. The γ′ precipitation kinetics are faster than stress relaxation kinetics in the HAZ, causing intergranular cracking. Best practice: always weld in the solution-annealed condition, then perform the complete solution + ageing heat treatment cycle after welding.
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| Process | Filler | Preheat | Max interpass temp | Post-weld HT |
|---|---|---|---|---|
| GTAW (TIG) | ERNiCrCo-1 | None (solution-annealed base metal) | 150°C | Full solution anneal + age required |
| GMAW (MIG) | ERNiCrCo-1 | None | 150°C | Full solution anneal + age required |
2.4632 vs Inconel 718 vs Waspaloy: Which Superalloy to Choose?
Engineers in power generation and aerospace routinely face this three-way selection. Each alloy occupies a distinct temperature capability and cost window.
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| Criterion | 2.4632 — NiCr20Co18Ti | Inconel 718 (2.4668) | Waspaloy (2.4654) |
|---|---|---|---|
| Max service temperature | ~920°C | ~700°C | ~980°C |
| Room-temp tensile strength | ~1,250 MPa | ~1,380 MPa | ~1,270 MPa |
| Creep resistance at 850°C | Excellent | Poor — too hot | Excellent |
| Weldability | Moderate (SAC risk) | Good | Moderate (SAC risk) |
| Machinability | Difficult (Group 4) | Moderate (Group 3) | Difficult (Group 4) |
| Relative raw material cost | Moderate | Moderate | Higher (Mo & higher Co) |
| Primary strengthening phase | γ′ Ni₃(Al,Ti) | γ″ Ni₃Nb | γ′ Ni₃(Al,Ti) |
| Typical forging applications | Turbine blades, discs, valve seats (750–920°C) | Compressor discs, shafts, fasteners (<700°C) | High-pressure turbine discs, blades (<980°C) |
Choose 2.4632 (NiCr20Co18Ti) when service temperature is 750–920°C and both creep resistance and oxidation resistance are required at moderate cost. Choose Inconel 718 for applications below 700°C requiring maximum room-temperature strength (~1,380 MPa) and good weldability. Choose Waspaloy only when service exceeds 920°C and budget permits the higher alloy cost.
Industrial Applications of 2.4632 Forged Parts
Power Generation — the Largest Market
Gas and steam turbines account for the largest global consumption of 2.4632 / NiCr20Co18Ti. In gas turbines, the alloy is used for first- and second-stage turbine blades, turbine discs, seal rings, labyrinth rings, and high-temperature bolting. In steam turbines it is used in control valve spindles, valve seats, and guide vanes operating in superheated steam above 500°C. Jiangsu Liangyi Co., Limited supplies 2.4632 turbine components to power generation customers in Asia, Europe, and the Middle East.
Aerospace & Aviation
Aircraft engine exhaust valves, turbine case segments, high-temperature springs, and combustion chamber liners use 2.4632 / NiCr20Co18Ti where the combination of temperature capability, fatigue resistance, and non-magnetic character is required. The alloy meets the material requirements of AMS 5829 and AMS 5830 for aerospace bar and ring product forms.
Automotive & Motorsport
High-performance diesel and petrol engine exhaust valves represent a high-volume application. Exhaust valves in 2.4632 must survive repeated thermal cycles from cold starts to sustained running above 800°C while maintaining sealing force. The alloy's creep resistance and thermal fatigue life at these temperatures is superior to standard exhaust valve stainless steels.
Tool & Die — Aluminium Die Casting Inserts
Hot-work tooling for aluminium and magnesium die casting faces intense cyclic thermal shock from approximately 200°C to 700°C per injection shot. 2.4632 / 2.4969 die casting inserts show significantly longer service life compared to H13 tool steel inserts because the alloy's higher thermal fatigue resistance suppresses heat-checking crack initiation.
Oil & Gas
High-temperature valve seats and stems in refinery heaters, steam crackers, and HPHT (high pressure, high temperature) downhole completions use 2.4632 where service temperatures exceed the capability of duplex stainless steels and aggressive process environments rule out carbon steels.
Serving all five industries above, Jiangsu Liangyi Co., Limited produces 2.4632 / NiCr20Co18Ti forgings to customer drawings and specifications. Request a custom 2.4632 forging quote — include material standard, dimensions, heat treatment condition, and NDT requirements for a same-day response.
Alloy Selection Decision Framework
Use this four-step process when evaluating whether 2.4632 / NiCr20Co18Ti is the right material choice for your application:
Check service temperature
If maximum metal temperature is below 650°C, consider 316 stainless or Alloy 625 first — they are cheaper and easier to machine. If temperature is 750–920°C, 2.4632 is likely optimal. Above 950°C, evaluate Waspaloy or directionally solidified alloys depending on stress level and budget.
Assess the dominant damage mechanism
If creep governs design life: 2.4632's γ′ strengthening gives excellent resistance. If corrosion fatigue dominates: evaluate chromium level against the specific environment. If low-cycle thermal fatigue is primary: specify tight grain size control in the forging specification, as LCF life is strongly grain-size dependent.
Define the product form
Turbine blades → open-die forging. Rings and flanges → seamless rolled ring (product form 2.4969). Discs → pancake forging. Bars for further machining → round bar forging. Each form has different minimum order quantities, lead times, and press capacity requirements; specify product form early.
Confirm standard, condition, and NDT
State the applicable standard (EN 10302:2008, AMS 5829, etc.), required heat treatment condition (+P precipitation hardened, +SA solution annealed, or as-forged), hardness range if specified, and NDT methods (UT, FPI, MPI if applicable) with acceptance class and applicable standard. These items plus dimensions form a complete, unambiguous procurement specification.
Frequently Asked Questions
2.4632 is the DIN/EN material number for NiCr20Co18Ti (UNS N07090 / DIN 2.4969), a precipitation-hardenable nickel-chromium-cobalt superalloy also identified by the trade name Nimonic® Alloy 90 (a trademark of Special Metals Corporation). Key properties: max service temperature 920°C, minimum tensile strength 1,100 MPa (precipitation-hardened, per EN 10302:2008), density 8.18 g/cm³. Applications include gas turbine blades, turbine discs, valve seats, and seamless rolled rings.
Both 2.4632 and 2.4969 refer to the same NiCr20Co18Ti chemical composition. The 2.4969 designation is used in DIN/EN standards specifically for the seamless rolled ring and tube product form, while 2.4632 is the general designation for bars, discs, and open-die forgings. Specify the correct designation on engineering drawings to ensure the MTC references the right product-form standard.
No. Nimonic® 80A (DIN 2.4952, UNS N07080) contains approximately 20% Cr, 2% Ti, and 1% Al but no cobalt. Adding 15–21% cobalt in 2.4632 (NiCr20Co18Ti) substantially raises the γ′ solvus temperature and improves creep life above 800°C. Nimonic® 80A is preferable below 750°C where cost is prioritised; 2.4632 is chosen for the 750–920°C range. Nimonic® is a registered trademark of Special Metals Corporation.
Two stages are required: (1) Solution annealing at 1080°C ± 10°C for 4–8 hours, followed by rapid air cool or water quench to below 600°C within 10 minutes. (2) Precipitation ageing at 700°C ± 10°C for a minimum of 16 hours, then air cool to room temperature. Both stages must be performed in a controlled-atmosphere or vacuum furnace. This develops the EN 10302:2008 minimum properties of Rm ≥ 1,100 MPa, Rp₀.₂ ≥ 700 MPa, A ≥ 15%.
Choose 2.4632 (NiCr20Co18Ti) when service temperature is 750–920°C and both creep resistance and oxidation resistance are required — typical for gas turbine blades, turbine discs, and steam valve stems. Choose Inconel 718 for applications below 700°C requiring the highest room-temperature strength (approximately 1,380 MPa) and excellent weldability, such as compressor discs, shafts, and fasteners.
Applicable NDT methods: Ultrasonic Testing (UT) per ASTM E2375 or EN 10228-3 for volumetric defect detection; Liquid Penetrant Inspection (FPI/LPI) for surface-open defects. Magnetic Particle Inspection (MPI) is not applicable because 2.4632 is non-magnetic. Radiographic Testing (RT) may be specified for complex geometries where UT coverage is limited. State the required method, acceptance standard, and class in your RFQ.
Density of 2.4632 (NiCr20Co18Ti) in the precipitation-hardened condition: 8.18 g/cm³. Melting range: 1310–1370°C. Elastic modulus at 20°C: 213 GPa. Specific heat capacity at 20°C: 397 J/(kg·K). Thermal conductivity at 20°C: 11.47 W/(m·K). Thermal expansion coefficient (20–100°C): 12.7 × 10⁻⁶ K⁻¹. The alloy is non-magnetic.
Typical lead times from Jiangsu Liangyi Co., Limited: 4–6 weeks for standard bar stock in the solution-annealed condition; 8–12 weeks for custom open-die forgings with full precipitation heat treatment and NDT; 10–14 weeks for large seamless rolled rings over 2 m diameter. Contact sales@jnmtforgedparts.com or call +86-13585067993 to discuss your requirements.
2.4632 Forged Parts from Jiangsu Liangyi Co., Limited
Jiangsu Liangyi Co., Limited has manufactured precision 2.4632 / NiCr20Co18Ti forged parts since 1997 (25+ years) from their 80,000 m² facility in Jiangyin, Jiangsu Province, China. The company holds ISO 9001:2015 quality management system certification.
Production capabilities include open-die forgings and seamless rolled rings from 30 kg to 30,000 kg per piece, with an annual forging capacity of 120,000 tonnes. Equipment includes 2,000–6,300 tonne hydraulic presses and 1–5 metre ring rolling machines.
Product range: forged round bars, square bars and flat bars; seamless rolled rings up to 6 m outer diameter; forged discs, plates, and flanges up to 3 m diameter; hollow bars, sleeves and bushings; and custom open-die forgings including turbine blades, valve seats, valve spindles, die blocks, and fasteners. Available with complete solution + precipitation heat treatment, EN 10204 3.1 or 3.2 material test certificates, and NDT per customer specification.
2.4632 (NiCr20Co18Ti / 2.4969) Forged Parts — Full Specifications
Dimensional capabilities, product photos, heat treatment options (solution-annealed or precipitation-hardened), NDT requirements, MTC options (EN 10204 3.1 / 3.2), and a direct quote request form are all available on the dedicated product page at jnmtforgedparts.com.
Ready to Source 2.4632 / NiCr20Co18Ti Forgings?
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