Abstract: A method for manufacturing a super-refractory nickel-based alloy with a constituent composition such that the gamma-prime average precipitation quantity at 700° C. is at least 35 mol % includes a preparation step in which a material with a crystal grain diameter of 200 ?m or less is manufactured by hot extrusion and a processing step in which this material is subjected to cold plastic processing with a processing rate of at least 30%. The cold plastic processing can be performed a plurality of times with a cumulative processing rate of at least 30%, and heat treatment is not performed between instances of cold plastic processing. The super-refractory nickel-based alloy can have a linear organization of a gamma phase and a gamma-prime phase or can include a carbide aggregated in an isometric crystal organization that includes a gamma phase and a gamma-prime phase.

Abstract: Ni-based super heat-resistant alloys have a composition in which the equilibrium precipitated amount of a gamma prime phase at 700° C. is 35 mol % or greater, and have grains having a maximum diameter of 75 nm or less in cross-sectional structure. One Ni-based super heat-resistant alloy manufacturing method includes preparing a raw material of a Ni-based super heat-resistant alloy having the aforementioned composition, and performing plastic processing of the raw material a plurality of times at a temperature of 500° C. or less so as to obtain a cumulative processing rate of 30% or greater. Another Ni-based super heat-resistant alloy manufacturing method includes preparing an alloy material having the aforementioned composition, a hardness of 500 HV or greater, and the aforementioned crystal grain maximum diameter, performing plastic processing of the alloy material at a temperature of 500° C. or less, and obtaining an alloy having a hardness of 500 HV or greater.