Haynes 188 Sheet Suppliers

Haynes 188, also known as Alloy 188, is a cobalt-based superalloy primarily used in high-temperature applications where both strength and resistance to oxidation and corrosion are crucial. The alloy is widely recognized for its exceptional performance in extreme environments, making it a preferred material in various industries, particularly in aerospace and gas turbine applications.

Composition and Properties

Haynes 188 is composed predominantly of cobalt, with significant additions of chromium, nickel, tungsten, and small amounts of lanthanum. The typical chemical composition is as follows:

• Cobalt (Co): Balance
• Chromium (Cr): 21-23%
• Nickel (Ni): 20-24%
• Tungsten (W): 13-16%
• Lanthanum (La): 0.02-0.12%
• Iron (Fe): ≤ 3%
• Silicon (Si): ≤ 1.25%
• Manganese (Mn): ≤ 1.25%
• Carbon (C): 0.05-0.15%

This unique combination of elements gives Haynes 188 its superior characteristics:

• High-temperature strength: The alloy maintains its strength at temperatures up to 1093°C (2000°F), making it ideal for high-stress applications.
• Oxidation resistance: Haynes 188 exhibits excellent oxidation resistance due to the formation of a stable oxide layer that protects the material from further degradation at elevated temperatures.
• Corrosion resistance: The alloy is highly resistant to a wide range of corrosive environments, including those containing sulfur and chlorine, which are typically challenging for many materials.
• Good formability: Despite its strength, Haynes 188 is relatively easy to form and fabricate, allowing for the production of complex shapes and components.

Applications

The exceptional properties of Haynes 188 make it suitable for a variety of demanding applications, particularly in the aerospace and power generation industries. Common uses include:

• Gas turbine components: Due to its ability to withstand extreme temperatures and corrosive environments, Haynes 188 is often used in the production of combustion chambers, afterburners, and other critical components of gas turbines.
• Aerospace parts: The alloy’s high-temperature capabilities and oxidation resistance make it a valuable material for manufacturing components such as exhaust nozzles and augmentor rings in jet engines.
• Industrial heating systems: Haynes 188 is also employed in industrial applications that require materials capable of enduring prolonged exposure to high temperatures, such as in heat exchangers and furnace components.

Fabrication and Welding

Haynes 188 can be fabricated using conventional methods, including machining, forming, and welding. However, due to its high strength and work-hardening characteristics, certain considerations must be made during fabrication:

• Machining: Carbide tools are generally recommended for machining Haynes 188. Due to its work-hardening tendency, slower cutting speeds and higher feed rates are advisable.
• Forming: The alloy can be cold-formed but may require intermediate annealing to relieve stresses and improve ductility.
• Welding: Haynes 188 can be welded using techniques such as gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW). Preheating and post-weld heat treatment are typically unnecessary, but stress relief treatments can be applied to reduce residual stresses.

Conclusion

Haynes 188 sheet is an indispensable material in industries that demand high-performance alloys capable of withstanding harsh environments. Its unique combination of high-temperature strength, oxidation and corrosion resistance, and good fabricability makes it a top choice for critical applications in aerospace, power generation, and industrial sectors. Whether it’s used in gas turbines or jet engines, Haynes 188 continues to be a reliable and versatile alloy for advanced engineering solutions.