Which Superalloys are highly in demand among worldwide industries?
Superalloys are also called as Heat Resisting Alloys or High Temperature alloys that are extremely important materials. Superalloys are rich in nickel, cobalt and iron. These maintain structural surface and retain their characteristics at the high temperatures under extreme stress and in vigorous environment.
Over the time titanium, aluminum and chromium are successfully added for enhancing the superalloy properties for furnace gate and shaker hearth applications. Superalloys are heat resistant alloys comprising of nickel, nickel-iron and cobalt that offer a great combination of mechanical strength and prevent surface damage. Actually, these are widely used in gas turbines, coal conversion plants, chemical plants and other applications that need heat and corrosion resistance.
A significant characteristic of nickel base alloys is their usefulness in load-handling applications at temperatures near about their melting points, a limit higher than general engineering materials.
Superalloys are categorized as:
- Nickel based
- Iron based
- Cobalt based
Iron based superalloys are inspired from austenitic stainless steels. These are more affordable than their nickel or cobalt based counterparts. The alloys that can be reinforced by a martensitic type of transformation that are austenitic and are reinforced by a series of hot and cold processing.
Iron based super alloys offer high and room temperature strength and prevent creeping, oxidation attack, wear and corrosion.
Cobalt based superalloys are used that can go above 1100oC. The strength of these materials is lower than their nickel based counterparts but they maintain their strength to the higher points. High strength is achieved by the presence of refractory metal carbides that stack up at grain boundaries and make alloy stable up to its melting point. Moreover cobalt based super alloys comprise of high concentration of chromium to make them highly corrosion resistant that is needed in hot exhaust gas applications. These alloys are also less susceptible to cracks in the thermal shocks.
Nickel based super alloys are the most commonly used alloys for hot applications and by most metallurgists. About 50% of their produced volume is only used in aircraft engines. Surface stability of nickel is significantly enhanced by chromium and aluminum. The main application of these alloys is in gas turbine engines for service in commercial and military aircrafts, space crafts, submarines, nuclear plants, military electric equipments, chemical processing tubes and heat exchanger tubes.
These alloys are more commonly used in aircraft development and electric power production units. Nickel based super alloys offer enhanced oxidation and nitriding resistance that make them significant material in chemical processing applications
Commonly used nickel based super alloys are:
- Inconel 600 (76% Nickel-15% Chromium – 8% Iron)
- Inconel 601 (61% Nickel-Silicon-Aluminum)
- Inconel X750 ( Nickel- Aluminum- Titanium)
- Inconel 718 (55% Nickel- 21% Chromium- 5% Niobium- 3% Molybdenum)
- Hastelloy X (48% Nickel – 22% Chromium – 18% Iron – 9% Molybdenum + Tungsten)
The high temperature and high strength Inconel 600 wire offers service up to 1000oF.
Heanjia Super-Metals is a well reputed manufacturer and distributor of Nickel based super alloys. We are based in China and supplying high strength and corrosion resistant alloys to industries across the globe.