What are high temperature alloys? The development history of high temperature alloys
It is understood that high-temperature alloys are alloy materials that can withstand certain stress at certain high temperatures and have the ability to resist oxidation or corrosion. Next, let's take a closer look at what high-temperature alloys are and their development history.
Introduction:
High-temperature alloys are divided into three types of materials: 760℃ high-temperature materials, 1200℃ high-temperature materials and 1500℃ high-temperature materials, with a tensile strength of 800MPa. In other words, it refers to high-temperature metal materials that work for a long time at temperatures above 760--1500°C and under certain stress conditions. They have excellent high-temperature strength, good resistance to oxidation and hot corrosion, good fatigue properties, fracture toughness and other comprehensive properties. It has become an irreplaceable key material for hot-end components of gas turbine engines for both military and civilian use.
High-temperature alloys are mainly used to manufacture high-temperature components such as turbine blades, guide vanes, turbine discs, high-pressure compressor discs and combustion chambers for aviation, naval and industrial gas turbines. They are also used to manufacture aerospace vehicles, rocket engines, nuclear reactors, petrochemical equipment and Coal conversion and other energy conversion devices.
development path:
Since the late 1930s, Britain, Germany, the United States and other countries have begun to study high-temperature alloys. During World War II, in order to meet the needs of new aerospace engines, the research and use of high-temperature alloys entered a period of vigorous development. In the early 1940s, the United Kingdom first added a small amount of aluminum and titanium to the 80Ni-20Cr alloy to form a γ phase for strengthening, and developed the first nickel-based alloy with high high-temperature strength. During the same period, in order to meet the needs of the development of turbochargers for piston aeroengines, the United States began to use Vitallium cobalt-based alloys to make blades.
In addition, the United States has also developed Inconel nickel-based alloy to make the combustion chamber of jet engines. Later, in order to further improve the high-temperature strength of the alloy, metallurgists added tungsten, molybdenum, cobalt and other elements to the nickel-based alloy, increased the aluminum and titanium content, and developed a series of alloy brands, such as the British "Nimonic", the American "Mar-M" and "IN", etc.; in cobalt-based alloys, elements such as nickel and tungsten are added to develop a variety of high-temperature alloys, such as X-45, HA-188, FSX-414, etc. Due to the lack of cobalt resources, the development of cobalt-based superalloys is restricted.
In the 1940s, iron-based superalloys were also developed. In the 1950s, brands such as A-286 and Incoloy901 appeared. However, due to poor high-temperature stability, development has been slow since the 1960s. The Soviet Union began to produce "ЭИ" brand nickel-based superalloys around 1950, and later produced "ЭП" series deformed superalloys and ЖС series cast superalloys. China began trial production of high-temperature alloys in 1956, and gradually formed the "GH" series of deformed superalloys and the "K" series of cast superalloys. In the 1970s, the United States also used new production processes to manufacture directional crystallized blades and powder metallurgy turbine disks, and developed high-temperature alloy components such as single-crystal blades to meet the increasing needs of aircraft engine turbine inlet temperatures.
So far, all countries are researching new high-temperature alloys, making continuous breakthroughs, innovating, and expanding application fields. In the development of modern industry, they have obviously become an indispensable alloy material.
