NI-BASED ALLOY PRODUCT AND METHOD FOR PRODUCING SAME

• Main Authors: IMANO, Shinya, KAMOSHIDA, Hironori
• Format: Patent
• Language: English; French; German
• Published: 18.03.2020
• Subjects: ALLOYS; CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS ANDNON-FERROUS ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; TREATMENT OF ALLOYS OR NON-FERROUS METALS

An Ni-based alloy product is a production base material for a Ni-based alloy member in which a y' (gamma prime) phase that is thermodynamically stable in a temperature range of 700 to 900°C is present at a ratio of 36 to 60 volume %. The Ni-based alloy product has a two-phase structure composed of a γ phase and γ' phase that is incoherent in crystalline lattice parameters with the γ' phase. The Ni-based alloy product has a two-phase structure composed of a crystalline grains of a γ (gamma) phase and crystalline grains of the γ' (gamma prime) phase that is incoherent in crystalline lattice parameters with the γ phase, the incoherent γ' phase being present at a ratio of 20 volume % or higher in the two-phase structure. The Ni-based alloy product has a Vickers hardness equal to or less than 400 Hv. A method for producing the Ni based alloy product has the following steps:melting a Ni-based alloy material having a composition such that a γ' phase at a ratio of 36 to 60 volume % can be precipitated; andhot-forging the Ni-based alloy material obtained through the melting step at temperatures equal to or higher than 1000°C, and within a temperature range of coexisting γ' phase and γ phase, and in a state of the γ' phase precipitating at a ratio of 10 volume % or higher,wherein during the step of hot-forging, the temperature of the hot-forging is lowered to a temperature by 100°C or more below a hot-forging start temperature.