Nimonic 263 Product Introduction
Product Overview
Nimonic 263 (UNS N07263) is a nickel-chromium-cobalt (Ni-Cr-Co) precipitation-hardened superalloy developed for ultra-high-temperature applications requiring exceptional creep rupture strength and oxidation resistance. Unlike Monel series (Ni-Cu-based, corrosion-focused) or Incoloy series (Ni-Fe-Cr-based, medium-temperature service), Nimonic 263 features a tailored composition with chromium (20-24%) for oxidation protection, cobalt (10-14%) for high-temperature matrix stability, and titanium/aluminum (Ti: 1.9-2.4%, Al: 0.3-0.7%) for γ' phase (Ni₃(Ti,Al)) precipitation hardening. This design enables it to operate stably at long-term service temperatures up to 850℃ (short-term up to 1000℃) while maintaining excellent creep resistance (e.g., 800℃/10,000-hour creep strength ≥140 MPa). Widely used in aerospace gas turbines, industrial power generation, and high-temperature chemical processing, it is the benchmark material for critical hot-section components where “ultra-high-temperature performance + structural durability” are non-negotiable.
International Grade Comparison
Standard System | Grade | Description |
ASTM (USA) | N07263 | UNS Unified Numbering System Grade (exclusive for Nimonic 263) |
EN (EU) | NiCr23Co12Mo | EN 10088-1 Standard Grade (high-temperature creep-optimized superalloy) |
JIS (Japan) | NW07263 | JIS G4902 Standard Grade (equivalent to Nimonic 263) |
DIN (Germany) | 2.4650 | DIN 17750 Standard Grade (Ni-Cr-Co-based high-temperature alloy) |
ISO (International) | NiCr23Co12Mo | ISO 6363 Standard Grade (aerospace-grade high-temperature superalloy) |
Physical Properties (Room Temperature & High-Temperature Highlights)
Property Indicator | Typical Value (Room Temp) | Unit | High-Temperature Performance Advantage |
Tensile Strength | ≥900 | MPa | 800℃ tensile strength: ≥650 MPa; 900℃: ≥420 MPa |
Yield Strength (0.2% Offset) | ≥550 | MPa | 800℃ yield strength: ≥480 MPa; no significant softening up to 850℃ |
Elongation (50mm Gauge Length) | ≥25 | % | Retains ≥15% elongation at 800℃ |
Fatigue Strength (10⁷ cycles, room temp) | ≥400 | MPa | 700℃ fatigue strength: ≥320 MPa |
Density | 8.35 | g/cm³ | Higher than Ni-Cu/Ni-Fe alloys due to Co/Cr content |
Melting Point | 1360-1410 | ℃ | Stable liquidus/solidus up to 1000℃ short-term service |
Thermal Expansion Coefficient (20-800℃) | 14.2×10⁻⁶ | /°C | Controlled expansion to minimize thermal stress in cycling |
Chemical Composition (Mass Fraction, Key Elements for High-Temp Performance)
Chemical Symbol | Composition Range (%) | Role in High-Temperature Service |
Ni | Balance (≥50) | Maintains austenitic matrix stability; base for γ' phase formation |
Cr | 20.0-24.0 | Forms dense Cr₂O₃ film; resists oxidation up to 1000℃ |
Co | 10.0-14.0 | Enhances high-temperature creep strength; inhibits γ' phase coarsening |
Mo | 5.0-6.0 | Solid-solution strengthening; improves creep resistance at 700-850℃ |
Ti | 1.9-2.4 | Primary γ' phase former (Ni₃Ti); core precipitation hardener |
Al | 0.3-0.7 | Co-forms γ' phase (Ni₃Al); refines γ' particle size |
C | 0.05-0.15 | Forms MC carbides (TiC); strengthens grain boundaries |
B | 0.005-0.015 | Improves grain boundary cohesion; reduces intergranular cracking |
Zr | 0.02-0.10 | Stabilizes carbides; enhances hot workability |
S/P | ≤0.015/≤0.02 | Ultra-low impurities to prevent high-temp brittleness |
Product Characteristics
1.Exceptional High-Temp Creep Resistance: γ' phase (Ni₃(Ti,Al)) + Mo solid-solution strengthening deliver 800℃/10,000-hour creep rupture strength ≥140 MPa—outperforming most Incoloy alloys and suitable for gas turbine hot sections;
2.Superior Oxidation & Corrosion Resistance: 20-24% Cr content forms a self-healing Cr₂O₃ oxide film, resisting scaling in air, combustion gases, and weak oxidizing atmospheres up to 1000℃;
3.Excellent Thermal Stability: γ' phase remains fine and stable (no coarsening) after 10,000 hours at 850℃; no brittle intermetallic phases (e.g., sigma, mu) form, ensuring long-term structural reliability;
4.Good Weldability & Processability: Compatible with TIG/MIG welding (using matching Ni-Cr-Co fillers) and hot forging (at 1100-1180℃); post-weld heat treatment (solution annealing + aging) restores full creep strength;
5.Broad Temperature Adaptability: Performs reliably from room temperature to 1000℃ (short-term), suitable for components with large temperature gradients (e.g., gas turbine transition pieces).
Metallographic Structure
•Solution-Annealed State: Uniform face-centered cubic (FCC) austenitic matrix (ASTM grain size 4-7 grades) with Ti/Mo/Al dissolved; no visible γ' precipitates—ensuring good formability/weldability;
•Aged State (After Hardening): Austenitic matrix dispersed with nano-scale γ' phase (Ni₃(Ti,Al)) (20-50 nm in size) and fine MC carbides (TiC, 100-200 nm) at grain boundaries. γ' particles act as “dislocation barriers” to resist creep, while MC carbides strengthen grain boundaries—together enabling ultra-high-temperature load-bearing capacity.
Product Forms and Executive Standards
Product Form | Main International Executive Standards | Application Reference |
Plates/Sheets | ASTM B572, EN 10088-2 | Gas turbine combustion chambers, high-temp reactor liners |
Seamless Pipes/Tubes | ASTM B622, EN 10216-5 | Industrial gas turbine heat exchanger tubes, high-temp process pipelines |
Bars/Forgings | ASTM B574, EN 10269 | Gas turbine blades, vanes, and rotor disks; aerospace engine components |
Wires/Filler Metals | ASTM B755, EN 10250-3 | Welding filler wires for high-temp joints, precision high-temp springs |
Forged Components | ASTM B981, EN 10222-5 | Large gas turbine transition pieces, rocket engine nozzles |
