What is the high temperature alloy?

High temperature alloy refers to a type of metal composite material based on iron, nickel, and cobalt that can work at a high temperature above 600 ℃ and a certain degree of in-situ stress. It has excellent high temperature compressive strength and excellent resistance Oxidation and heat corrosion resistance, excellent fatigue characteristics, impact toughness and other comprehensive properties, also known as "superalloy".  It is mainly used in the aerospace industry and power energy industry.

high temperature alloy /superalloy classification

1.Iron-based superalloy

Iron-based superalloys can also be called high-temperature-resistant carbon steels. Its matrix is Fe, and a small amount of Ni, Cr and other alloy elements are added. The high temperature carbon steel can be divided into austenite, martensite, ferrite, and ferritic heat-resistant steel according to its quenching regulations.

2.Nickel-based superalloy

The nickel content of nickel-based superalloys is more than half, which is suitable for working standards above 1000 ℃. The production process of heat treatment and tempering and aging is selected, which can greatly increase the stress relaxation resistance and compressive strength and tensile strength. improve. Based on the analysis of superalloys used in high-temperature natural environments, the scope of application of nickel-based superalloys far exceeds the use of iron-based and cobalt-based superalloys. In addition, nickel-based superalloys are also a kind of superalloy with large production volume and large demand in my country. Many turbine blades and engine combustion chambers of turbine engines, and even turbochargers, also use nickel-based superalloys as raw materials. For more than a century and a half, the high temperature raw materials used in aircraft engines have increased from 750°C in the late 1940s to 1200°C in the late 1990s. It should be said that this tremendous improvement has also promoted the forging process. And surface coatings are developing rapidly.

3.Cobalt-based superalloy

Cobalt-based superalloys are based on cobalt, and the content of cobalt is about 60%. In addition, Cr, Ni and other elements must be added to improve the temperature resistance of the superalloy. Although this kind of superalloy has good temperature resistance, it is because of the cobalt resources of various countries The production volume is relatively small, and the production and processing are relatively difficult, so the use volume is small. Generally used for high-temperature standards (600-1000℃) and long-term extreme and complex geo-stressed high-temperature components, such as aircraft engine leaves, supercharged discs, hot end components of engine combustion chambers and aerospace engines. In order to obtain better temperature resistance, the general standard needs to add elements such as W, MO, Ti, Al, Co during preparation to ensure its excellent heat resistance and fatigue resistance.