Bar and Rod
Plate and Sheet
Strip
Pipe and Tube
Wire
Welding
Powder Material
Cast Products
Forged Products
Fittings
Fastening
Round Bar:
φ2–500 mm, 1–6 m length
Flat/Square Bar:
4–100 mm thickness/width
Hex Bar:
A/F 3–100 mm
Hollow Bar:
OD 20–300 mm
Sheet:
0.3–6 mm thickness
Medium Plate:
6–25 mm thickness
Heavy Plate:
25–100 mm thickness
Standard Strip:
0.05–3 mm thick,
10–600 mm wide
Precision strip:
0.01–0.5 mm thick,
tight tolerance ±0.005 mm
Foil:
0.005–0.1 mm thick
Seamless Tube:
OD 6–450 mm,
WT 1–50 mm,
1–12 m length
Welded Tube:
OD 10–600 mm,
WT 1–20 mm
Capillary Tube:
OD 1–10 mm,
WT 0.1–2 mm
Wire Form:
Cold Drawn Wire,
Bright Wire,
Spring Wire,
Fine Wire,
Ultra-fine Wire
General Diameter:
φ0.1–10 mm
Coil Weight:
50–500 kg,
customizable tolerance
Solid Wire:
φ0.8–4.0 mm
Flux-cored Wire:
φ1.2–4.0 mm
Welding Rod:
φ2.0–5.0 mm
Powder Form:
AM 3D Printing Powder,
Spherical Powder,
Gas-atomized Powder,
Water-atomized Powder
Particle Size:
10–150 μm
Sphericity:
≥90% for AM grade
Cast Ingot:
φ200–800 mm
Precision Casting:
min wall 0.5 mm
Cast Pipe:
OD 100–600 mm,
WT 10–50 mm
Forged Bar:
Φ35–500 mm
Forged Ring:
OD 200–2000 mm
Forging Weight:
1–5000 kg
Fittings Form:
Elbow, Tee, Reducer, Flange, Cap, Outlet, Lap Joint
Size range:
1/2''–24'' (DN15–DN600)
Wall thickness:
Sch10–Sch160, STD, XS, XXS
Pressure Class:
150–2500 LB
Fastening Form:
Bolt, Nut, Screw, Stud, Washer, Pin, Rivet
Metric: M3–M64
Imperial: #4–2.5''
Length: 6–500 mm
2.4634 is a wrought nickel–cobalt–chromium-base alloy strengthened by additions of molybdenum, aluminium and titanium, developed for high-strength, creep-resistant service at temperatures up to 950 °C (1740 °F). This datasheet presents the material within the European (EN / Werkstoff-Nummer / BS) standard system.
It combines the high strength of the age-hardening nickel-base alloys with good creep resistance. Cobalt (~20%) and chromium (~15%) provide matrix strength and oxidation resistance; molybdenum gives solid-solution strengthening; and the relatively high aluminium (~4.7%) with titanium forms a substantial gamma-prime [Ni₃(Al,Ti)] phase during aging, providing high tensile and creep-rupture strength. The increased aluminium also improves oxidation resistance relative to earlier grades.
It is produced by high-frequency air melting and casting, or — for more critical applications — by vacuum melting and electroslag refining. Typical applications include gas-turbine blades, discs, forgings and ring sections, and high-temperature bolts and fasteners. Strength is developed by a solution treatment followed by aging; the high aluminium-plus-titanium content makes the alloy more challenging to weld than lower-strength grades.
Values per official datasheet, solution-treated and aged condition.
| Property | Value | Unit |
|---|---|---|
| Density | 7.99 | g/cm³ |
| Melting range | 1290–1345 | °C |
| Young's modulus (20 °C) | 224 | GPa |
| Specific heat capacity (20 °C) | 419 | J/kg·K |
| Thermal conductivity (20 °C) | 10.8 | W/m·K |
| Electrical resistivity (20 °C) | 1.30 | µΩ·m |
| Coefficient of thermal expansion (20–100 °C) | 12.2 | µm/m·°C |
| Maximum creep-resistance temperature | ~950 | °C |
Composition per DIN 17742 (W.Nr. 2.4634, NiCo20Cr15MoAlTi).
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Nickel | Ni | Balance | — | Base; FCC matrix |
| Cobalt | Co | 18.0 | 22.0 | Solid-solution + γ′ strengthening |
| Chromium | Cr | 14.0 | 15.7 | Oxidation / corrosion resistance |
| Molybdenum | Mo | 4.5 | 5.5 | Solid-solution strengthening |
| Aluminium | Al | 4.5 | 4.9 | γ′ Ni₃Al precipitation strengthening |
| Titanium | Ti | 0.9 | 1.5 | γ′ precipitation strengthening |
| Iron | Fe | — | 1.0 | Residual |
| Manganese | Mn | — | 1.0 | Deoxidiser |
| Silicon | Si | — | 1.0 | Deoxidiser |
| Carbon | C | 0.05 | 0.20 | Carbide strengthening |
| Boron | B | — | 0.02 | Grain-boundary strengthening |
| Zirconium | Zr | — | 0.15 | Grain-boundary strengthening |
| Phosphorus | P | — | 0.02 | Residual impurity |
| Sulphur | S | — | 0.015 | Residual impurity |
Nominal: Ni-20Co-15Cr-5Mo-4.7Al-1.2Ti. A high-γ′ age-hardenable Ni-Co-Cr-Mo alloy with high aluminium for maximum precipitation strengthening; developed for the most demanding creep service to ~950 °C — gas-turbine blades.
Solution-treated and aged condition, per DIN 17742 for W.Nr. 2.4634.
| Property | Value | Unit |
|---|---|---|
| Tensile strength (Rm) | ≥1100 | MPa |
| 0.2% proof strength (Rp0.2) | ≥750 | MPa |
| Elongation at fracture (A) | ≥15 | % |
| Brinell hardness | ~320–400 | HB |
Values per EN/DIN; confirm against the inspection certificate (EN 10204).
| Environment | Performance | Notes |
|---|---|---|
| Creep / stress-rupture (to 950 °C) | Outstanding | Co + high-γ′ strengthening; primary selling point |
| High-temperature oxidation | Very Good | Higher Al improves scale stability vs earlier |
| High-cycle fatigue | Excellent | High fatigue strength |
| Thermal stability | Excellent | Stable γ′ for long-term high-temperature service |
| Chloride stress-corrosion cracking | Good | High nickel content |
| General corrosion | Good | Ni-Co-Cr base |
A precipitation-hardening alloy. Strength is developed by solution treatment followed by aging.
Solution Treatment Temperature: ~1149 °C (2100 °F), air cool
Aging Temperature: ~1075 °C/4 h/AC + ~850 °C/16 h/AC (typical multi-stage), air cool Purpose: precipitates a high volume fraction of γ′ [Ni₃(Al,Ti)] for maximum tensile and creep-rupture strength.
The high aluminium-plus-titanium content increases susceptibility to strain-age cracking, so heat-treatment and welding sequences must be controlled.
Weldable by GTAW, GMAW, SAW and SMAW, but the high aluminium-plus-titanium content makes the alloy markedly more susceptible to strain-age cracking than lower-strength grades. Welding is done in the solution-treated condition, with age-hardening applied afterwards.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG · GMAW / MIG | Possible (solution-treated; care needed) | Matching Ni-Co-Cr-Mo filler (solution-treated base) |
| SAW / SMAW | Possible | Matching Ni-Co-Cr electrode |
Use a matching filler metal; if unavailable, a filler rich in Ni-Co-Cr-Mo may be used. Control restraint and pre/post-weld heat treatment to avoid cracking.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Preferred condition | Solution-treated (machine before final aging where possible) |
| Tooling | Avoid plain carbon steels (galling risk); use soft die materials + heavy-duty lubricants |
| Work hardening | High rate; rigid setup, positive rake, sharp tooling |
| Coolant | Generous flood coolant |
Forming Processes
| Process | Notes |
|---|---|
| Hot working | High-temperature hot working; ESR/vacuum-melt for critical parts |
| Cold forming | Good ductility; conventional methods + heavy-duty lubricants |
| Final aging | After forming/machining to develop full strength |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Gas turbines | Turbine blades, discs, forgings, ring sections | High creep-rupture strength to 950 °C |
| Aerospace | Aero-engine hot-section components | High strength + oxidation + fatigue resistance |
| High-temperature fasteners | Bolts and fasteners | High-temperature strength |
| Industrial gas turbines | Hot-section structural parts | Long-term creep strength |
| Product Form | Standard | Other |
|---|---|---|
| Round bar and extruded section | BS HR3 | AFNOR NK20CDA / NCKD20ATv |
| Forgings | W.Nr. 2.4634 | MSRR 7017 / 7018 |
| Composition / designation | W.Nr. 2.4634 · NiCo20Cr15MoAlTi | ISO NW3021 · AECMA PrEN 2179–2181 |
| Welding consumables | Matching Ni-Co-Cr-Mo filler | — |
W.Nr. 2.4634 (NiCo20Cr15MoAlTi); BS HR3; AFNOR NK20CDA; ISO NW3021.
| W.Nr. | Ni % | Cr % | Other | Best Used For |
|---|---|---|---|---|
| 2.4634 | ~54 | ~15 | Co 20, Mo 5, Al 4.7 | Age-hardened Ni-Co-Cr; creep to 950°C |
| 2.4632 | bal | 18–21 | Co ~18, Ti+Al | Age-hardened Ni-Cr-Co; to 920°C |
| 2.4952 | bal | 18–21 | Ti+Al (no Co) | Age-hardened Ni-Cr; to 815°C |
| 2.4636 | bal | ~15 | Co 15, higher Al+Ti | Highest strength; to 1010°C |
| 2.4654 | bal | 18–21 | Co 12–15, Mo | Comparable γ′ superalloy; >700°C |
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