Mitsubishi Heavy Industries Limited

Mitsubishi Hitachi Power Systems, Ltd.

Mitsubishi Power, Ltd.

Atsuo Ota

Shinya Imano

Hironori Kamoshida

There is provided a Co-based alloy material, having a chemical composition including: Al of 0.1 to 10 mass %; W of 3 to 45 mass %, the total content of Al and W being 50 mass % or less; O of 0.007 to 0.05 mass %; and the balance being Co and impurities, wherein in γ phase crystal grains as a matrix phase of the Co-based alloy material, segregation cells within an average size of 0.15 to 1.5 μm are formed, wherein in the segregation cells, γ′ phase grains within a size of 0.01 to 0.5 μm including Co, Al and W are dispersively precipitated, and wherein on boundary regions of the segregation cells and grain boundaries of the γ phase crystal grains, μ phase grains within a size of 0.005 to 2 μm including Co and W are dispersively precipitated.

Co-based alloy material, co-based alloy product, and method for manufacturing said product

Provided is a method for manufacturing an Ni-based alloy member in which the equilibrium amount of &#x3b3;' phase precipitation at 700&#xb0; C. is from 30 to 70 volume %. The method includes the steps of preparing an Ni-based alloy powder having a predetermined chemical composition; forming a precursor body wherein an average grain diameter of the &#x3b3; phase grains is 50 &#x3bc;m or less, by using the Ni-based alloy powder; and heating the precursor body to a temperature at least the &#x3b3;&#x2032; phase solvus temperature and subsequently slow-cooling the heated precursor body from the temperature to a temperature at least 100&#xb0; C. lower than the &#x3b3;&#x2032; phase solvus temperature at a cooling rate of 100&#xb0; C./h or lower. There is obtained a softened body in that the &#x3b3;&#x2032; phase particles of at least 20 volume % precipitate between/among the &#x3b3; phase grains having an average grain diameter of 50 &#x3bc;m or less.

Method for manufacturing Ni-based alloy member

This method for manufacturing a high-temperature component formed of a Ni-based alloy includes a step of subjecting a workpiece of the Ni-based alloy to hot die forging using predetermined dies to form a forge-molded article, the step including: a die/workpiece co-heating substep of heating the workpiece interposed between the dies to a forging temperature; and a hot forging substep of taking out the workpiece and the dies into a room temperature environment and immediately performing hot forging on the workpiece using a press machine. The predetermined dies are formed of another Ni-based superalloy comprising &#x3b3; and &#x3b3;' phases, and have features in that: a solvus temperature of the &#x3b3;&#x2032; phase is 1050-1250&#xb0; C.; and the &#x3b3;&#x2032; phase precipitates at least 10 vol. % at 1050&#xb0; C. and has two kinds of forms of intra-grain &#x3b3;&#x2032; phase precipitations within the &#x3b3; phase grains and inter-grain &#x3b3;&#x2032; phase precipitations between/among the &#x3b3; phase grains.

Method for manufacturing nickel-based alloy high-temperature component

To provide a manufacturing process of a Ni based superalloy and a member of the Ni based superalloy which achieves both of excellent workability in a manufacturing step of the Ni based superalloy of the precipitation strengthening type which contains much amount of the gamma prime phase and excellent high temperature strength of the Ni based superalloy. The manufacturing process of a Ni based superalloy includes a step for softening the Ni based superalloy and improving the workability, in which the step for softening the Ni based superalloy and improving the workability is a step for precipitating the gamma prime phase that is incoherent with a gamma phase that is a matrix by 20 vol % or more.

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Yokohama, Japan

Atsuo Ota