Common types of high-temperature alloys

1. GH4169 high-temperature alloy
GH4169 alloy is a nickel chromium iron based high-temperature alloy. GH4169 alloy is a nickel based deformation high-temperature alloy. Nickel based alloys are one of the most complex alloys. It is widely used in the manufacturing of various high-temperature components. At the same time, it is also the most noticeable alloy among all high-temperature alloys. Its relative usage temperature is also the highest among all ordinary alloy systems. The proportion of this alloy in advanced aircraft engines is over 50%.
GH4169 alloy is an age hardened nickel chromium iron based deformation alloy developed by Eiselstein from the Huntington branch of the international nickel company, and publicly introduced in 1995. The alloy is a nickel base deformed superalloy with body centered cubic g "and face centered cubic g 'phases as precipitation strengthening. It has high tensile strength, yield strength and good plasticity below 650 ℃, good corrosion resistance, radiation resistance, fatigue, fracture toughness and other comprehensive properties, as well as satisfactory welding and post welding formability. The alloy has stable microstructure and properties over a wide temperature range of -253~650 ℃, making it a widely used high-temperature alloy under deep cooling and high temperature conditions. Due to its excellent comprehensive performance, GH4169 is widely used in compressor discs, compressor shafts, compressor blades, turbine discs, turbine shafts, casings, fasteners, and other structural and sheet welding components of aviation engines [3].
China began to develop GH4169 alloy in the 1970s, mainly used in disk parts with a relatively short service life. Therefore, a dual process of vacuum induction and electroslag remelting was adopted. Since the 1980s, it has been applied in the aviation field, and improving the quality of materials, enhancing the comprehensive performance and reliability of alloys has become the main research direction. The main research directions of GH4169 alloy currently include:
(1) Improving the smelting process, quantifying smelting parameters, achieving stable program operation, making the microstructure of the alloy more uniform, thereby obtaining excellent yield and fatigue strength as well as crack propagation and crack arrest ability, and improving low cycle fatigue strength;
(2) Improve the heat treatment process. The heat treatment process cannot effectively eliminate the segregation at the center of the steel ingot, which has a negative impact on the uniformity of the structure. Therefore, adopting a reasonable homogenization annealing process to obtain fine-grained billets has become one of the main research directions;
(3) Improve usage design. Due to the fact that the working temperature of GH4169 cannot be higher than 650 ℃, it is necessary to strengthen the cooling of components and fully utilize the high performance, low cost and other advantages of this high-temperature alloy;
(4) Improve organizational stability performance. Due to the long service life requirements of aviation engine components, it is also crucial to improve the long-term aging microstructure stability of GH4169 alloy.