Superalloys, also known as heat-resistant alloys or high-temperature alloys, are classified into four groups, i.e., nickel-based, cobalt-based, iron/nickel-based, and titanium-based alloys. Superalloys exhibit high-temperature corrosion resistance, oxidation resistance, and creep resistance. Among these superalloys, nickel-based superalloys are used predominantly in hazardous components of aircraft engines and gas turbines. The categorization of nickel-based superalloys is made on the basis of their chemical composition. The different grades of nickel-based superalloys, along with their composition and properties, are summarized in Nickel-based superalloys, owing to their excellent properties, such as fatigue strength, thermal stability, and resistance to corrosion, are used under severe conditions; in fact, nearly 50% by weight of aircraft engines are made up of nickel-based superalloys. In addition, these alloys are used in aircraft gas turbines, for example, disks, combustion chambers, bolts, castings, shaft exhaust systems, blades, vanes, etc.; steam turbine power plants, for example, bolts, blades, stack gas reheaters; reciprocating engines, for example, turbocharger, exhaust valves, hot plugs, etc.; metal processing, for example, hot work tool and dies, casting dies; medical applications, for example, dentistry uses, prosthetic devices; space vehicles; heat treating equipment; nuclear power systems; chemical and petrochemical industries; pollution control equipment; and coal gasification and liquefaction systems.for more information see https://doi.org/10.1016/B978-0-12-803581-8.09817-9
| Different grades of nickel-based superalloys |
Composition | Properties |
|---|---|---|
| Inconel 718 | Ni 54.48, Cr 17.50, Fe 22.3, Nb 4.90, Al 0.66, Ti 0.96 |
Precipitation hardenable, high creep-rupture strength at high temperatures to about 7001C and excellent strength. Precipitates of primary niobium carbide (NbC), titanium carbide (TiC) diskshaped gamma double prime precipitates (Ni3Nb), and needle-like precipitates of δ (Ni3Nb) present |
| Inconel 100 | Ni 60, Cr 10, Co 15, Mo 3, Al 5.5, Ti 4.7, C 0.18, B 0.014, Zr 0.06 |
Precipitation hardenable, high rupture strength through 8701C. The high percentages of titanium, aluminum, and low refractory metal increase strength-to-density ratio |
| Inconel 825 | Ni 37.1, Fe 32.2, Cr 22.8, Mo 3.24, Cu 2.07, Ti 0.859, C 0.0155 |
Good resistance to pitting, intergranular corrosion, chloride-ion stress-corrosion cracking, and general corrosion in a wide range of oxidizing and reducing environments |
| IN-713LC | Ni 74.2, Cr 12.6, Mo 4.9, Nb 1.96, Al 5.7, Zr 0.1, Ti 0.63, C 0.047, B 0.007 |
Good combination of tensile and creep-rupture properties as a result of gamma-prime strengthening enhanced by solid solution and grain-boundary strengthening, and good castability |
| Udimet 720LI | Ni 57.4, Cr 16, Co 15, Mo 3, Ti 5, Al 2.5, W1, C 0.1 |
Solid solution strengthened with tungsten and molybdenum and precipitation-hardened with titanium and aluminum. High strength, excellent impact strength retention at elevated temperatures, good oxidation and corrosion resistance, and high degree of work hardening |
| FGH95 | Ni 62.5, Cr 12.98, Co 8.00, Nb, 3.50, Al 3.48, Ti 2.55, W 3.40, Mo 3.40, C 0.060, B 0.012 |
Precipitation hardened having higher tensile and yield strength at 6501C. A compact structure after hot isostatic pressing (HIP) consisting of coarse gamma prime phase (g0) precipitated along previous particle boundaries (PPB) appear in the grain |
| ME-16 | Ni 56.3, Cr 10.4, Co 20.5, Al 3.1, Ti 2.6, W 3, Ta 1.4, Mo 1.3, Nb 1.4 |
Good strength and creep resistance at high temperatures (600–8001C). Good resistance to fatigue crack initiation at the lower temperatures (300–6001C). Can maintain strength and lower density at elevated temperature |
| RR1000 | Ni 52.4, Cr 15, Co 18.5, Mo 5, Ti 3.6, Al 3, Ta 2, Hf 0.5, C 0.03 |
Solid solution strengthened with chromium, molybdenum, and cobalt. Good strength, good toughness, creep resistance, good oxidation, and corrosion resistance at high temperature |
| Nimonic C-263 | Ni 51.0, Cr 20.0, Co 20.0, Mo 5.8, Ti 2.2, Al 0.5 |
A readily weldable, age-hardenable superalloy with excellent strength, ductility, and corrosion resistance up to around 8501C. Molybdenum for solid-solution strengthening |
| Nimonic 105 | Ni 54.0, Co 20.0, Cr 15.0, Mo 5.0, Al 4.7, Ti 1.3 |
An age-hardenable superalloy within creased aluminum for improved oxidation-resistance and strength, and high creeprupture properties up to around 9501C. Strengthened by additions of molybdenum, aluminum, and titanium |
| Nimonic 75 | Ni 80.5, Cr 19.5 | Good corrosion and heat resistance, high-temperature strength, and outstanding oxidation-resistance |
| Nimonic 80 A | Ni 76.0, Cr 19.5, Ti 2.4, Al 1.4 | An age-hardenable creep-resistant alloy for service at temperatures up to around 8151C |
| Hastelloy alloy C-2000 | Ni 47, Cr 22, Fe 18, Mo 9, Co 1.5, W 0.6 | Localized corrosion resistance, good resistance to hot acids, and excellent resistance to stress-corrosion cracking |
| Haynes 282 | Ni 57, Cr 20, Co 10, Mo 8.5, Ti 2.1, Al 1.5, Fe 1.5, Mn 0.3, Si 0.15, C 0.06, B 0.005 |
g0 precipitation strengthened nickel based superalloy along with excellent creep properties, fabricability, and thermal stability |
