Introduction to the main grades and characteristics of high-temperature alloys

Main grades of high temperature alloys:

Solid solution strengthened iron-based alloys:

GH1015, GH1035, GH1040, GH1131, GH1140

Age-hardenable iron-based alloys:

GH2018, GH2036, GH2038, GH2130, GH2132, GH2135, GH2136, GH2302, GH2696

Solid solution strengthened nickel-based alloy:

GH3030, GH3039, GH3044, GH3028, GH3128, GH3536, GH605, GH600

Age-hardening nickel-based alloys:

GH4033, GH4037, GH4043, GH4049, GH4133, GH4133B, GH4169, GH4145, GH4090

Foreign high-temperature alloys include inconel series, incoloy series, Hastelloy series

760℃ high temperature material deformation high temperature alloy

Deformable high temperature alloy refers to a type of alloy that can be subjected to hot and cold deformation processing, has an operating temperature range of -253 to 1320°C, has good mechanical properties and comprehensive strength and toughness indicators, and has high oxidation and corrosion resistance. According to its heat treatment process, it can be divided into solid solution strengthening alloys and aging strengthening alloys. The first digit after GH indicates the classification number, i.e. 1. Solid solution strengthening iron-based alloy 2. Age hardening iron-based alloy 3. Solid solution strengthening nickel-based alloy 4. Cobalt-based alloy After GH, the second, third, and fourth digits indicate the sequence number.

1. Solid solution strengthened alloy

The operating temperature range is 900-1300℃, and the highest anti-oxidation temperature is 1320℃. For example, GH128 alloy has a room temperature tensile strength of 850MPa and a yield strength of 350MPa; a tensile strength of 140MPa and an elongation of 85% at 1000℃, and a lifespan of 200 hours and an elongation of 40% at 1000℃ and 30MPa stress. Solid solution alloys are generally used to make combustion chambers and casings of aviation and aerospace engines.

2. Age-hardened alloy

The operating temperature is -253～950℃, and it is generally used to make turbine pans and blades and other structural parts of aviation and aerospace engines. The alloy working temperature for making turbine pans is -253～700℃, and it is required to have good high and low temperature strength and anti-fatigue performance. For example: GH4169 alloy, the maximum yield strength at 650℃ is 1000MPa; the alloy temperature for making blades can reach 950℃, for example: GH220 alloy, the tensile strength at 950℃ is 490MPa, and the endurance life at 940℃ and 200MPa is more than 40 hours.

Deformed high-temperature alloys mainly provide structural forgings, cakes, rings, bars, plates, pipes, strips and wires for aerospace, aviation, nuclear energy, and petroleum civilian industries. High-temperature alloys refer to a type of metal material based on iron, nickel, and cobalt that can work for a long time at high temperatures above 600°C and under certain stresses; and have high high-temperature strength, good oxidation resistance and corrosion resistance, good fatigue performance, fracture toughness and other comprehensive properties. High-temperature alloys are single austenitic structures, with good organizational 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". They are 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 use 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 parts of aviation jet engines and various industrial gas turbines. If the endurance strength of 150mpa-100h is used as the standard, the highest temperature that nickel alloys can withstand is >1100℃, while nickel alloys are about 950℃ and iron-based alloys are <850℃, that is, nickel-based alloys are correspondingly 150℃ to 250℃ higher. So people call nickel alloys the heart of the engine. At present, nickel alloys have accounted for half of the total weight in advanced engines. Not only turbine blades and combustion chambers, but also turbine disks and even the blades of the last few compressors have begun to use nickel alloys. Compared with iron alloys, the advantages of nickel alloys are: higher operating temperature, stable organization, less harmful phases and greater resistance to oxidation and corrosion. Compared with cobalt alloys, nickel alloys can work under higher temperatures and stresses, especially in the case of moving blades.