Method for producing Ni-base superheat-resistant alloy and Ni-base superheat-resistant alloy

摘要

Provided are: a method for producing a Ni-based super-heat-resisting alloy having such a compositional formula that the equilibrium volume for precipitations in a gamma prime phase at 700°C can become 35 mol% or more; and a Ni-based super-heat-resisting alloy. The method according to the present invention comprises the steps of: (a) subjecting a material having such a compositional formula that the content of carbon is 0.01 to 0.25% by mass and the equilibrium volume for precipitations in a gamma prime phase at 700°C can become 35 mol% or more to a plastic working procedure multiple times at a temperature of 500°C or lower in such a manner that the cumulative working ratio from the material can become 40% or more, thereby producing a first worked material; (b) subjecting the first worked material to a heat treatment at a temperature of 900°C or higher, thereby producing a first heat-treated material; and (c) further subjecting the first heat-treated material to a plastic working procedure once or multiple times at a temperature of 500°C or lower in such a manner the cumulative working ratio from the first heat-treated material can become 10% or more, thereby producing a second worked material. The Ni-based super-heat-resisting alloy according to the present invention has the above-mentioned compositional formula, wherein the defect rate in a cross-sectional structure is 0.5% by area or less.