What type of metal is Hastelloy?
What is Hastelloy?
Hastelloy is the trade name for a group of corrosion-resistant nickel-based alloys. In addition to nickel, these alloys contain other elements such as molybdenum and chromium. These alloys are particularly known for their corrosion resistance, good machinability and resistance to medium and high temperatures (depending on the alloy grade). Hastelloy alloys are generally metastable over the normal operating temperature range (room temperature to approximately 427 °C). This metastability is characterized by a gamma (FCC) phase microstructure achieved by solution annealing and rapid cooling. Although designed to resist second phase precipitation during short-term thermal excursions above 500 °C, long-term exposure reveals its equilibrium, multiphase nature.
What are other terms for Hastelloy metal?
There is no other term that universally represents all alloys in the Hastelloy family. However, Hastelloy metal is a high temperature alloy. This term refers to a group of high-performance alloys characterized by excellent mechanical strength, resistance to thermal creep deformation, and outstanding corrosion resistance, especially at high temperatures. Each specific alloy within the Hastelloy family, such as Hastelloy C-276, Hastelloy C-22 and Hastelloy B-2, represents a unique composition within this broader superalloy class.
What is the origin of Hastelloy?
Hastelloy is a registered trademark owned by Haynes International, Inc., an American company specializing in the development and production of high-performance alloys. The nickel-based superalloy industry began in 1921 when a family of nickel-molybdenum compositions was patented. This laid the foundation for the progressive development of the entire Hastelloy series of alloys, which are renowned for their ability to resist corrosion and high temperatures. Shortly thereafter, the first metals bearing the Hastelloy name, Hastelloy A and Hastelloy B, were produced. The unique composition of Hastelloy B is still used today.
In 1926, Hastelloy C alloy was introduced. The latest version, Hastelloy C-2000 alloy, is widely used in the chemical processing industry. Around the same time, Hastelloy D alloy was developed, a nickel-silicon-copper alloy. Today, the newest variant, Hastelloy D-205 alloy, is used in chemical plants that handle hot, highly concentrated sulfuric acid.
What is Hastelloy metal made of?
Hastelloy is a nickel-based alloy that typically contains about 40-70% nickel. Other metals such as chromium (1-33%) and molybdenum (5-30%) are added to increase the metal's corrosion resistance. Iron can also be added in percentages from 0 to 18%. Other ingredients that may also be included in varying percentages include: tungsten, carbon, cobalt, zirconium, titanium, aluminum, copper, and manganese. The exact chemical composition of some common Hastelloy grades varies depending on the desired properties.
How is Hastelloy metal made?
Hastelloy is manufactured by mixing pure elements in liquid form to obtain various grades of specific chemical compositions. The mixture typically contains nickel, chromium, molybdenum and iron, with additional elements such as tungsten, vanadium, carbon and titanium added depending on the grade. After the elements are combined, the alloy is smelted at high temperatures to ensure an even mix. The molten Hastelloy is then cast into ingots and other forms. After casting, the material undergoes shaping processes such as forging or rolling and heat treatment to optimize mechanical properties. Final processing makes the alloy suitable for a specific application.
