NiCr20Ti is a solution-strengthened 80/20 nickel–chromium alloy with controlled additions of titanium and carbon, providing good resistance to high-temperature oxidation and corrosion together with useful strength and excellent formability. This datasheet presents the material within the European (DIN / EN / Werkstoff-Nummer / BS) standard system.
First introduced in the 1940s for early gas-turbine components, it remains a basic heat-resistant alloy. The 18–21% chromium content forms a continuous, adherent Cr₂O₃ scale that gives oxidation protection up to 1100 °C, while the small titanium addition refines the grain-boundary carbide distribution and improves scale adhesion under thermal cycling. Strengthening is by solid solution and a modest carbide dispersion; the alloy is not age-hardenable, which keeps it readily weldable and forgeable.
Its service envelope is principally 550–1100 °C in oxidising atmospheres, where oxidation resistance, weldability and formability are required and stress levels are low to moderate. Typical applications include gas-turbine ancillary parts (casings, shrouds, combustion supports), welded rings, industrial-furnace internals and heat-treatment fixtures, and nuclear components. Below ~550 °C, austenitic stainless steels are usually more economical; above ~815 °C under sustained stress, precipitation-hardened alloys (e.g. , 263, Waspaloy) are preferred.
Values per manufacturer data, solution-annealed condition.
| Property | Value | Unit |
|---|---|---|
| Density | 8.37 | g/cm³ |
| Melting range | 1340–1380 | °C |
| Young's modulus (20 °C) | 206 | GPa |
| Specific heat capacity (20 °C) | 461 | J/kg·K |
| Thermal conductivity (20 °C) | 11.7 | W/m·K |
| Electrical resistivity (20 °C) | 1.18 | µΩ·m |
| Coefficient of thermal expansion (20–100 °C) | 12.7 | µm/m·°C |
| Maximum oxidation-resistance temperature | ~1100 | °C |
| Useful strength to | ~815 | °C |
Composition per DIN 17742 / EN 10095 (W.Nr. 2.4951 / 2.4630, NiCr20Ti).
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Nickel (+ Co) | Ni | Balance | — | Base; FCC matrix |
| Chromium | Cr | 18.0 | 21.0 | Oxidation / corrosion resistance |
| Iron | Fe | — | 5.0 | Residual |
| Titanium | Ti | 0.2 | 0.6 | Carbide former (stabiliser) |
| Carbon | C | 0.08 | 0.15 | Carbide strengthening |
| Manganese | Mn | — | 1.0 | Deoxidiser |
| Silicon | Si | — | 1.0 | Deoxidiser |
| Copper | Cu | — | 0.5 | Residual |
| Cobalt | Co | — | 2.0 | Residual |
| Phosphorus | P | — | 0.02 | Residual impurity |
| Sulphur | S | — | 0.015 | Residual impurity |
Nominal: Ni-20Cr-0.4Ti. A solid-solution (non-age-hardening) Ni-Cr alloy with a small titanium addition; used for oxidation- and corrosion-resistant components to ~1000 °C. (W.Nr. 2.4951 = solution-annealed delivery; 2.4630 is also used for this grade.)
Solution-annealed (+AT) condition, per DIN 17742 for W.Nr. 2.4951.
| Property | Value | Unit |
|---|---|---|
| Tensile strength (Rm) | ≥620 | MPa |
| 0.2% proof strength (Rp0.2) | ≥240 | MPa |
| Elongation at fracture (A) | ≥30 | % |
| Brinell hardness | ≤230 | HB |
Values per EN/DIN; confirm against the inspection certificate (EN 10204).
| Environment | Performance | Notes |
|---|---|---|
| Static high-temperature oxidation | Good | Continuous Cr₂O₃ scale; protection to ~1100 °C |
| Cyclic high-temperature oxidation | Good | Ti improves scale adhesion under thermal cycling |
| Carburisation | Moderate | Typical of 80/20 Ni-Cr |
| General atmospheric / mild media | Excellent | Ni-Cr base |
| Chloride stress-corrosion cracking | Good | High nickel content |
| Creep / rupture strength | Moderate | Not an age-hardening alloy; low-to-moderate stress only |
A solution-strengthened alloy; not age-hardenable. Heat treatment is for annealing only.
Anneal Temperature: 1050 °C (1920 °F), followed by air cooling Purpose: softening, recrystallisation and restoration of ductility.
The alloy can also be strain-hardened (cold-worked) for higher tensile strength where required. Strength derives from solid solution and a fine carbide dispersion, not from precipitation aging.
Readily welded — a key feature of this alloy, made possible by the absence of aluminium, niobium and cobalt. Suitable for MMA/SMAW, GTAW/TIG, GMAW/MIG and submerged-arc welding.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG · GMAW / MIG | Excellent | EN ISO 18274 matching Ni-Cr filler |
| SAW (submerged-arc) | Good | Matching submerged-arc wire + flux |
| SMAW / MMA | Good | Matching Ni-Cr electrode |
Clean joint preparation is essential. The alloy's good formability and weldability make it well suited to fabricated sheet and ring components.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Work hardening | Moderate (Ni-Cr behaviour); rigid setup, sharp tooling |
| Cutting | Positive rake, ample feed; flood coolant |
| Preferred condition | Solution-annealed |
Forming Processes
| Process | Notes |
|---|---|
| Hot forming | Standard hot-working practice for Ni-Cr alloys |
| Cold forming | Excellent formability; readily formed into sheet/ring components |
| Annealing | 1050 °C, air cool, after heavy cold work |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Gas turbines | Ancillary parts: casings, shrouds, combustion supports, welded rings | Oxidation resistance + weldability at low-moderate stress |
| Aerospace | Fabricated sheet components, rings, casings | Formability + oxidation resistance |
| Industrial furnaces | Furnace internals, heat-treatment fixtures | Repeated oxidising-atmosphere exposure |
| Nuclear | Fabricated high-temperature components | Oxidation resistance + stability |
| General high-temperature | Sheet/strip/forged parts running hot in oxidising atmospheres | Oxidation resistance to 1100 °C |
| Product Form | DIN Standard | BS / Other |
|---|---|---|
| Rod and bar | DIN 17752 | BS HR5 / HR203 / HR403 |
| Wire | DIN 17742 | — |
| Seamless tube | DIN 17751 | BS HR504 |
| Plate, sheet and strip | DIN 17750 | BS HR504 |
| Composition / designation | W.Nr. 2.4630 / 2.4951 · NiCr20Ti | AFNOR NC20T |
| Welding consumables | EN ISO 18274 matching Ni-Cr filler | — |
W.Nr. 2.4630 / 2.4951 (NiCr20Ti); BS HR5 / HR203 / HR403 / HR504.
| EN Symbol | Ni % | Cr % | Other | Best Used For |
|---|---|---|---|---|
| NiCr20Ti | bal | 18–21 | Ti 0.2–0.6 | Solution-strengthened; oxidation to 1100°C, low stress |
| NiCr20TiAl | bal | 18–21 | Ti+Al (age-hard.) | Age-hardened; higher strength to ~815°C |
| NiCr15Fe | ≥72 | 14–17 | Fe 6–10 | General high-temp; carburisation/nitriding |
| NiCr23Fe | 58–63 | 21–25 | Al 1.0–1.7 | Cyclic oxidation to 1250°C |
| NiCr23Co12Mo | 44.5 | 20–24 | Co+Mo | Gas-turbine hot section; high creep strength |




