UNS N07718 Inconel 718 Nickel-chromium Based High Temperature Alloy Rod
Inconel 718 nickel-chromium-based high-temperature alloy rods have become an important material in the fields of aerospace, energy, and chemical industry due to their excellent high-temperature strength, corrosion resistance, and creep resistance.
Material:
Inconel 718 (UNS N07718) is a precipitation-strengthened nickel-chromium-based high-temperature alloy. By adding elements such as niobium (Nb), molybdenum (Mo), aluminum (Al) and titanium (Ti), γ'' (Ni₃Nb) and γ' (Ni₃(Al,Ti)) strengthening phases are formed, so that it can maintain excellent mechanical strength, creep resistance and corrosion resistance at high temperatures.
Main components (wt.%):
Nickel (Ni): 50-55% (matrix)
Chromium (Cr): 17-21% (anti-oxidation/corrosion)
Iron (Fe): Balance (reduces cost and stabilizes austenite structure)
Niobium + Molybdenum (Nb+Mo): ~5% (main strengthening element)
Aluminum + Titanium (Al+Ti): 0.8-1.2% (auxiliary strengthening)
Core characteristics:
- High temperature performance: long-term working temperature can reach 700°C (1290°F), short-term resistance to 980°C (1800°F).
- High strength: yield strength (≥1030 MPa) and tensile strength (≥1240 MPa) far exceed ordinary stainless steel.
- Corrosion resistance: Resistant to chloride stress corrosion, oxidation, and sulfidation environments, suitable for acidic and marine environments.
- Processing friendliness: Mechanical properties can be further improved by age-hardening.
| Core performance advantages |
| Features | Description |
| High temperature strength | High yield strength (≥800 MPa) at 650°C (1200°F) and short-term resistance to 980°C (1800°F). |
| Oxidation resistance/corrosion resistance | Resistant to chloride stress corrosion, sulfide environment, acid and seawater corrosion, more than 5 times better than 304 stainless steel. |
| Fatigue and creep resistance | Not prone to deformation or cracking under high-frequency cyclic loads and long-term high-temperature stress. |
| Weldability and formability | Weldable (TIG/electron beam welding), recoverable by age hardening after cold working. |
Heat treatment:
Solution treatment: 955°C ±10°C, 1 hour/25mm thickness, water quenching.
Age hardening: 720°C ±5°C (8 hours) → 620°C ±5°C (8 hours), air cooling.
-
| Selection comparison (Inconel 718 vs. other high temperature alloys) |
| Alloy | Maximum operating temperature | Key Benefits | Limitation |
| Inconel718 | 700℃ | Best comprehensive performance, high cost performance | When the temperature is >650℃ for a long time, the γ" phase will coarsen. |
| Inconel 625 | 870℃ | Higher corrosion resistance, no age hardening | Lower strength (yield strength ~550 MPa). |
| Haynes 282 | 800℃ | Better creep resistance | High cost and difficult processing. |
-
Typical application areas
Aerospace: jet engine turbine discs, compressor shafts, combustion chamber components (accounting for more than 50% of aviation alloy usage)
Energy industry: gas turbine blades, nuclear reactor pressure vessel bolts
Petrochemical: downhole tools, valve stems, high-corrosion environment pump shafts
Automobile racing: turbocharger housings, exhaust system high-temperature bolts
Quality Assurance:
-
Full process control: vacuum induction melting (VIM) + electroslag remelting (ESR) to ensure low oxygen/sulfur content.
More grades:
|
|
UNS N07718 Inconel 718 Nickel-chromium Based High Temperature Alloy Rod Images
|
