Research on the corrosion resistance of nickel-based superalloys
Superalloys are a type of high-temperature structural material based on iron, cobalt and nickel. They can usually work in a high-temperature environment above 600°C, have surface stability, and can withstand large and complex stresses. Superalloys are also called heat-resistant alloys, heat-resistant alloys or superalloys. They are widely used in the nuclear industry, aerospace industry, etc. The continuous deepening of superalloy research has not only promoted the progress of cutting-edge science and technology such as the national defense industry, but also promoted the technological development of national economic industries such as the nuclear power industry, energy and power, transportation and petrochemical industry.
Nickel-based superalloys are the most widely used and highest-temperature strength superalloys among superalloys. The main reasons are:
(1) Nickel-based superalloys can dissolve more alloy elements and maintain good structural stability;
(2) Nickel-based superalloys can form a coherent and ordered AB-type intermetallic compound [Ni3(Al,Ti)] phase as a strengthening phase, which greatly strengthens the alloy performance;
(3) Cr-containing nickel-based superalloys have good oxidation resistance and gas corrosion resistance.
In modern gas turbine engines, more than 50% (mass fraction) of the materials are made of high-temperature alloys, of which the use of nickel-based high-temperature alloys accounts for about 40% (mass fraction) of the engine materials. Nickel-based alloys have excellent comprehensive properties at medium and high temperatures, are suitable for long-term work at high temperatures, and can resist corrosion and abrasion. Therefore, nickel-based high-temperature alloys are often used as key hot end components of modern aircraft engines, spacecraft and rocket engines, as well as ships and industrial gas turbines. At the same time, nickel-based high-temperature alloys are also important high-temperature structural materials required in nuclear reactors, coal conversion technology, chemical technology, etc. Nickel-based deformed high-temperature alloys are a type of alloy with good mechanical properties and comprehensive strength and toughness indicators in nickel-based alloys, and have high oxidation resistance and corrosion resistance. Among them, Inconel625 alloy is a nickel-based deformed high-temperature alloy containing a large amount of Cr, Mo, Fe elements, and Nb as the main added element. The working temperature of Inconel625 alloy can be from deep cooling to 982℃. With its outstanding high strength, easy processing and corrosion resistance, it is widely used in aerospace, petrochemical, nuclear power, marine and other fields. In addition, GH4169 deformable high-temperature alloy has been widely used in the development of my country's aviation engines. In recent years, its performance and processing technology level have been significantly improved, and it can be applied to large aircraft engines and helicopter turboshaft series engines.
