SUPERALLIAGE A PROPRIETES OPTIMISEES ET DENSITE LIMITEE

Superalliage à propriétés optimisées et densité limitée L'invention concerne de nouvelles compositions de superalliage ayant une densité limitée et présentant, à chaud, de bonnes propriétés mécaniques ainsi qu'une bonne résistance à l'oxydation et à la corrosion. Figure pour l'abrégé : Fig. 1. A nickel-based superalloy includes, in atomic percentages, 13% to 21% chromium, 15% to 26% cobalt, 4% to 8% aluminum, 4.5% to 8% titanium, 8% to 18% iron, boron in an atomic percentage less than or equal to 0.5% or no boron, carbon in an atomic percentage less than or equal to 1% or no carbon, at least one additional element selected from molybdenum, tungsten, tantalum and niobium, a total atomic content of the at least one additional element being less than or equal to 1.5% or no such at least one additional element, the remainder being nickel and unavoidable impurities, with a sum of the atomic percentages of aluminum and titanium being comprised between 8.5% and 15%. The novel superalloy composition has a limited density and exhibiting, when hot, good mechanical properties as well as good resistance to oxidation and corrosion.