First of all, Hastelloy® is a registered trade name that belongs to Haynes International, Inc. Haynes is a producer of so called exotic alloys of types widely used in applications for the aerospace, nuclear, oil & gas and petrochemical industries whenever extreme chemical or corrosion resistance is required – especially at elevated temperatures. Hastelloy alloys generally have temperature ratings of around 2000° Fahrenheit.
Such alloys are also known as “superalloys” or “high-performance alloys”. Hastelloy is also an important material in the manufacture of jet engines and gas turbines – particularly for the turbine blades that must be durable at high temperature.
Haynes produces some 22 different grades of their Hastelloy alloy – one of these is designated as Hastelloy C276. They are all alloys that are predominately comprised of nickel alloyed with elements such as chromium, cobalt, manganese, molybdenum, titanium, zirconium, and tungsten amongst others.
Foil
When metals are rolled out into strips, the thinner ones are usually referred to as foil. Hastelloy C276 thin foil is typically from 0.001 inch to around 0.050 of an inch in thickness. The principal manufacturing width for the foil is 24 inches; length is more variable since single runs off the mill will be cut and coiled into convenient handling sizes. The foils can be supplied in “as rolled” condition or annealed. Engineers, suppliers and buyers will often lengthen the name to Hastelloy C276 heat resistant foil.
Applications for these foils are many and varied and somewhat dependent on the thickness. They are often used as a component part of heat reflective or heat shielding systems.
Alternatives
Hastelloy as a name is protected but the material itself is open to manufacture by anyone with the means to do so. Other branded materials such as Nickelvac® HC-276, Inconel® 276 or Nicrofer® 5716 are basically interchangeable with Hastelloy.
Cost
None of the materials that fall into the super alloy category are low in cost and designers intending to use such as Hastelloy C276 Foil on their projects should bear this in mind. They should try to be as economical as possible with the weight and volume of material to be used. They should also try to keep their finished part dimensions as close as possible to the readily available raw material sizes so as to avoid unnecessary wastage or premium pricing for non-standard supply. It goes without saying that they should only specify exotic alloys when the application demands it (as against a sort of “catch all” safety factor).
