Inconel

Inconel is a family of nickel-based superalloys designed for high-temperature strength and resistance to corrosion and oxidation. It is a brand-name alloy group developed for demanding applications and is trademarked by Special Metals Corporation, now part of Allegheny Technologies. The term covers a range of alloys, including common grades such as Inconel 600, 625, 718, and 800, each formulated for specific temperature and environmental requirements.

The alloys are characterized by a nickel-rich composition with chromium as a principal alloying element, and varying amounts of iron, niobium, molybdenum, titanium, aluminum, and other elements depending on the grade. They offer excellent strength at elevated temperatures, good creep resistance, and robust oxidation resistance, which makes them suitable for harsh service environments. Some grades are strengthened by precipitation hardening (for example, Inconel 718), while others rely on solid-solution strengthening. Inconel alloys can be more difficult to form and machine than other metals and often require specialized processing and welding techniques.

Applications for Inconel span aerospace, chemical processing, and energy sectors. They are used in turbine engines and hot sections, exhaust systems, heat exchangers, and chemical processing equipment, as well as certain nuclear components. While they share core properties, the performance of each grade is tailored to specific operating temperatures, stresses, and corrosive media.

As a brand, Inconel encompasses multiple standards and designations (such as UNS numbers and ASTM grades). Availability and cost depend on grade, size, and supplier.