Inconel751 (N07751) visokotemperaturna legura koja otvrdnjava precipitacijom
Inconel 751/ Legura 751/2.4694/ N07751
hemijski sastav
C(%): Manje ili jednako 0.10
Si(%): Manje ili jednako 0.01
Mn(%): Manje ili jednako 1.00
Cr(%): 14.0-17.0
Ni(%): veće ili jednako 70.0
Po(%): -
Co(%): -
W(%): -
Al(%): 0.90-1.50
Cu(%): Manje ili jednako 0.50
Ti(%): 2.00-2.60
Fe(%): 5.00-9.00
Ostali (%): Nb {{0}}.70-1.20, S manje ili jednako 0.01, Nb 2.50-3.50
Inconel 751 je visokotemperaturna legura koja se stvrdnjava na taloženje slična 750. Ima dobru otpornost na habanje, dobru čvrstoću, otpornost na koroziju i vruću tvrdoću na visokim temperaturama. Koristi se za ispušne ventile na motorima sa unutrašnjim sagorevanjem itd.
High-temperature alloy refers to a type of metal material based on iron, nickel, and cobalt that can work at high temperatures above 600°C and under certain stress for a long time; and has high high-temperature strength, good anti-oxidation and anti-corrosion properties, Good fatigue performance, fracture toughness and other comprehensive properties. High-temperature alloys have a single austenite structure and have good structural stability and reliability at various temperatures. Based on the above performance characteristics, and the high degree of alloying of high-temperature alloys, they are also called "superalloys". An important material widely used in aviation, aerospace, petroleum, chemical industry, and ships. According to the matrix elements, high-temperature alloys are divided into iron-based, nickel-based, cobalt-based and other high-temperature alloys. The service temperature of iron-based high-temperature alloys can generally only reach 750~780°C. For heat-resistant parts used at higher temperatures, nickel-based and refractory metal-based alloys are used. Nickel-based high-temperature alloys occupy a particularly important position in the entire field of high-temperature alloys. They are widely used to manufacture the hottest components of aviation jet engines and various industrial gas turbines. If 150MPA-100H durability strength is used as the standard, the current maximum temperature that nickel alloys can withstand is >1100 stepeni, dok su legure nikla oko 950 stepeni, legure na bazi gvožđa su<850℃, that is, nickel-based alloys are correspondingly 150℃ higher. to about 250℃. So people call nickel alloy the heart of the engine. At present, in advanced engines, nickel alloys account for half of the total weight. Not only turbine blades and combustion chambers, but also turbine disks and even later compressor blades have begun to use nickel alloys. Compared with iron alloys, the advantages of nickel alloys are: higher working temperature, stable structure, fewer harmful phases, and greater resistance to oxidation and corrosion. Compared with cobalt alloys, nickel alloys can operate at higher temperatures and stresses, especially in moving blade applications.
Gore navedene prednosti legure nikla povezane su sa nekim od njenih odličnih svojstava. Nikl je lice centrirana kocka vrlo stabilne strukture i ne prolazi alotropsku transformaciju od sobne temperature do visoke temperature; ovo je veoma važno za izbor materijala matrice. Dobro je poznato da struktura austenita ima niz prednosti u odnosu na feritnu strukturu.
Nikl ima visoku hemijsku stabilnost, skoro da nema oksidacije ispod 500 stepeni, i na njega ne utiču topli vazduh, voda i određeni vodeni rastvori soli na akademskim temperaturama. Nikl se sporo otapa u sumpornoj kiselini i hlorovodoničkoj kiselini, ali se brzo otapa u azotnoj kiselini.
Nikl ima veliku sposobnost legiranja, te se štetne faze neće pojaviti ni kada se doda više od deset legirajućih elemenata, što pruža potencijalne mogućnosti za poboljšanje različitih svojstava nikla.
