Composition
Nickel (Ni): Serves as the base metal, providing a stable matrix and excellent resistance to many corrosive environments.
Chromium (Cr): Enhances the alloy's resistance to oxidation and corrosion, forming a protective chromium - oxide layer on the surface.
Molybdenum (Mo): Improves resistance to pitting and crevice corrosion, especially in chloride - containing environments. It also helps maintain the alloy's strength at high temperatures.
Other elements: Some Hastelloy alloys may contain additional elements like tungsten (W), cobalt (Co), iron (Fe), and copper (Cu) in varying amounts to further optimize specific properties such as strength, hardness, and resistance to specific corrosive media.
Types and Properties
Hastelloy C - 276: One of the most widely used Hastelloy alloys. It has excellent resistance to a broad range of corrosive chemicals, including strong acids like hydrochloric acid, sulfuric acid, and nitric acid. It also offers good resistance to stress - corrosion cracking and is suitable for use in high - temperature and high - pressure applications.
Hastelloy X: This alloy is known for its high - temperature strength and good oxidation resistance. It is often used in aerospace and industrial applications where components are exposed to elevated temperatures, such as in gas turbines and furnace components.
Hastelloy B - 3: Hastelloy B - 3 has outstanding resistance to hydrochloric acid and other reducing acids. It maintains good mechanical properties in corrosive environments and is commonly used in chemical processing applications involving these acids.
Applications
Chemical processing industry: Used in reactors, heat exchangers, pumps, and valves handling corrosive chemicals.
Oil and gas industry: Employed in downhole equipment, pipelines, and refinery components to resist corrosion from acidic gases and fluids.
Pharmaceutical industry: Suitable for equipment used in the production of drugs and chemicals, where high - purity and corrosion - free materials are required.
Aerospace industry: Utilized in components of jet engines and gas turbines due to its high - temperature performance and strength.
Power generation: Found in power plants, particularly in systems dealing with flue - gas desulfurization and other processes involving corrosive environments.
