Abstract: The metal powder producing apparatus includes: a first gas jet nozzle that includes jet holes disposed in a bottom surface of a gas jet device so as to form first rings each, and jets gas against molten metal flowing down through the liquid nozzles; a second gas jet nozzle that includes jet holes disposed in the bottom surface of the gas jet device so as to form second rings each on an outer side of a corresponding one of the first rings, and jets gas to prevent scatter of metal particles; and a third gas jet nozzle that includes jet holes disposed in the bottom surface of the gas jet device so as to form a third ring on an outer side of the second gas jet nozzle, and jets gas against an inner wall surface of the spray chamber.

Abstract: A metal-powder producing apparatus includes a spray chamber, and a plurality of spray nozzles that liquid-spray a melted metal into the spray chamber. Each of the plurality of spray nozzles includes: a liquid nozzle that allows the melted metal to flow down into the spray chamber; and a gas-jet nozzle that has a plurality of gas-jet holes arranged around the liquid nozzle and causing a gas fluid to collide with the melted metal having flowed down from the liquid nozzle.

Abstract: A metal powder production apparatus capable of easily preventing an oxide in a molten metal from entering a liquid nozzle is provided. The metal powder apparatus includes a first crucible heating and melting a melting material to generate molten metal, a first heating device heating and melting the metal in the first crucible, a stopper opening and closing a first opening provided on the bottom surface of the first crucible, an introduction pipe having one end connected to the first opening of the first crucible and leading a molten metal in the first crucible to the outside of the first crucible, a second crucible receiving the molten metal flowing out of the introduction pipe, a second heating device heating the second crucible, and a liquid nozzle provided on the bottom surface of the second crucible.

Abstract: The present invention aims to provide sintered materials of austenite steel powder each having a strength which is equivalent to or in excess of the strength of a Ni-based alloy and insusceptible to oxygen and turbine members each being composed of each sintered material. There is provided the sintered material of austenite steel powder which contains 25 to 50% Ni; 12 to 25% Cr, 3 to 6% Nb; 0.001 to 0.05% B; not more than 1.6% Ti; not more than 6% W; not more than 4.8% Mo; and not more than 0.5% Zr in percentage by mass, with a balance made up of Fe and unavoidable impurities.

Abstract: 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 working the Ni based superalloy softening material into a desired shape and a solution-aging step for obtaining a Ni based superalloy member. The composition of the Ni based superalloy contains, in mass %, 10% or more and 25% or less of Cr, 30% or less of Co, 3% or more and 9% or less of the total of Ti, Nb and Ta, 1% or more and 6% or less of Al, 10% or less of Fe, 10% or less of Mo, 8% or less of W, 0.03% or less of B, 0.1% or less of C, 0.08% or less of Zr, 2.0% or less of Hf, and 5.

Abstract: There is provided an additive manufactured (AM) article formed of a Co based alloy having a composition comprising: in mass %, 0.08-0.25% C; 0.1% or less B; 10-30% Cr; 30% or less in total of Fe and Ni, the Fe being 5% or less; 5-12% in total of W and/or Mo; 0.5-2% in total of Ti, Zr, Nb and Ta; 0.5% or less Si; 0.5% or less Mn; 0.003-0.04% N; and the balance being Co and impurities. The AM article comprises crystal grains with an average size of 10-100 ?m. In the crystal grains, segregation cells with an average size of 0.15-1.5 ?m are formed, in which components constituting an MC type carbide phase comprising the Ti, Zr, Nb and/or Ta are segregated in boundary regions of the cells, and/or grains of the MC type carbide phase are precipitated at an average intergrain distance of 0.15-1.5 ?m.

Abstract: 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 ? and ?? phases, and have features in that: a solvus temperature of the ?? phase is 1050-1250° C.; and the ?? phase precipitates at least 10 vol. % at 1050° C. and has two kinds of forms of intra-grain ?? phase precipitations within the ? phase grains and inter-grain ?? phase precipitations between/among the ? phase grains.

Abstract: There are provided: an Ni-based alloy member including a ?? phase precipitation with 36 to 60 volume % and exhibiting a high durable temperature and good cold workability; a method for producing the member; an Ni-based alloy product to be used as a precursor of the member; and a method for producing the product. The Ni-based alloy product has a two-phase structure composed of a ? phase and a ?? phase being incoherent to the ? phase, the incoherent ?? phase being present at a ratio of 20 volume % or higher. The Ni-based alloy member produced by cold working the Ni-based alloy product and subsequently by conducting heat treatment comprises a ? phase and a ?? phase being coherent to the ? phase, the coherent ?? phase being present at a ratio of 36 to 60 volume %, and has a predetermined shape.

Abstract: 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.

Abstract: There is provided an additive manufactured (AM) article formed of a Co based alloy having a composition comprising: in mass %, 0.08-0.25% C; 0.1% or less B; 10-30% Cr; 30% or less in total of Fe and Ni, the Fe being 5% or less; 5-12% in total of W and/or Mo; 0.5-2% in total of Ti, Zr, Nb and Ta; 0.5% or less Si; 0.5% or less Mn; 0.003-0.04% N; and the balance being Co and impurities. The AM article comprises crystal grains with an average size of 10-100 ?m. In the crystal grains, segregation cells with an average size of 0.15-1.5 ?m are formed, in which components constituting an MC type carbide phase comprising the Ti, Zr, Nb and/or Ta are segregated in boundary regions of the cells, and/or grains of the MC type carbide phase are precipitated at an average intergrain distance of 0.15-1.5 ?m.

Abstract: There is provided an additive manufactured (AM) article formed of a Co based alloy having a composition comprising: in mass %, 0.08-0.25% C; 0.1% or less B; 10-30% Cr; 30% or less in total of Fe and Ni, the Fe being 5% or less; 5-12% in total of W and/or Mo; 0.5-2% in total of Ti, Zr, Nb and Ta; 0.5% or less Si; 0.5% or less Mn; 0.003-0.04% N; and the balance being Co and impurities. The AM article comprises crystal grains with an average size of 10-100 ?m. In the crystal grains, segregation cells with an average size of 0.15-1.5 ?m are formed, in which components constituting an MC type carbide phase comprising the Ti, Zr, Nb and/or Ta are segregated in boundary regions of the cells, and/or grains of the MC type carbide phase are precipitated at an average intergrain distance of 0.15-1.5 ?m.

Abstract: There are provided: an Ni-based alloy member including a ?? phase precipitation with 36 to 60 volume % and exhibiting a high durable temperature and good cold workability; a method for producing the member; an Ni-based alloy product to be used as a precursor of the member; and a method for producing the product. The Ni-based alloy product has a two-phase structure composed of a ? phase and a ?? phase being incoherent to the ? phase, the incoherent ?? phase being present at a ratio of 20 volume % or higher. The Ni-based alloy member produced by cold working the Ni-based alloy product and subsequently by conducting heat treatment comprises a ? phase and a ?? phase being coherent to the ? phase, the coherent ?? phase being present at a ratio of 36 to 60 volume %, and has a predetermined shape.

Abstract: Provided herein are an austenite steel that satisfies desirable strength and desirable castability at the same time, and an austenite steel casting using same. The austenite steel according to an embodiment of the present invention contains Ni: 25 to 50%, Nb: 3.8 to 6.0%, Zr: 0.5% or less, B: 0.001 to 0.05%, Cr: 12 to 25%, Ti: 1.6% or less, Mo: 4.8% or less, and W: 5.2% or less in mass %, and the balance Fe and unavoidable impurities, wherein the parameter Ps represented by the following formula (1) satisfies Ps?38, Ps=8.3[Nb]?7.5[Ti]+2.4[Mo]+3.5[W]??formula (1), where [Nb], [Ti], [Mo], and [W] represent the contents of Nb, Ti, Mo, and W, respectively, in mass %.

Abstract: It is an objective of the invention to provide a steam turbine rotor of which a rotor shaft is made of a low-cost heat resistant ferritic steel and that can withstand high main steam temperatures of about 650° C. There is provided a steam turbine rotor comprising: a rotor shaft made of a heat resistant ferritic steel such as a 12-Cr steel; and a rotor blade made of a Ti—Al alloy, wherein the Ti—Al alloy includes: from 38 to 45 atomic % of Al; from 0.5 to 2 atomic % of V; from 2 to 6 atomic % of Cr and/or Mo; and the balance being Ti and incidental impurities.

Abstract: There is provided an additive manufactured (AM) article formed of a Co based alloy having a composition comprising: in mass %, 0.08-0.25% C; 0.1% or less B; 10-30% Cr; 30% or less in total of Fe and Ni, the Fe being 5% or less; 5-12% in total of W and/or Mo; 0.5-2% in total of Ti, Zr, Nb and Ta; 0.5% or less Si; 0.5% or less Mn; 0.003-0.04% N; and the balance being Co and impurities. The AM article comprises crystal grains with an average size of 10-100 ?m. In the crystal grains, segregation cells with an average size of 0.15-1.5 ?m are formed, in which components constituting an MC type carbide phase comprising the Ti, Zr, Nb and/or Ta are segregated in boundary regions of the cells, and/or grains of the MC type carbide phase are precipitated at an average intergrain distance of 0.15-1.5 ?m.

Abstract: Provided is a method for manufacturing an Ni-based alloy member in which the equilibrium amount of ?? phase precipitation at 700° 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 ? phase grains is 50 ?m or less, by using the Ni-based alloy powder; and heating the precursor body to a temperature at least the ?? phase solvus temperature and subsequently slow-cooling the heated precursor body from the temperature to a temperature at least 100° C. lower than the ?? phase solvus temperature at a cooling rate of 100° C./h or lower. There is obtained a softened body in that the ?? phase particles of at least 20 volume % precipitate between/among the ? phase grains having an average grain diameter of 50 ?m or less.

Abstract: In a manufacturing method of a turbine rotor blade using an Ni-based forged alloy, provided is a manufacturing method of a turbine rotor blade having an excellent workability and a high degree of freedom in the design of a cooling structure. A manufacturing method of a turbine rotor blade according to the present invention is, in a manufacturing method of a turbine rotor blade, using an Ni-based forged alloy, characterized by including: a softening process of increasing a ?? phase incoherent with a ? phase that is a matrix phase in the Ni-based forged alloy; a first working process of forming at least two members constituting a rotor blade by using the Ni-based forged alloy after subjected to the softening process; a second working process of forming cooling structural parts in the respective members; and a third working process of joining the members.

Abstract: A Ni-based alloy for a welding material including, by mass, 0.001 to 0.1% of C, 18 to 25% of Co, 16 to 20% of Cr, 2.5 to 3.5% of Al, 9.0 to 15.0% of Mo+W, 0.001 to 0.03% of B and the balance being Ni and inevitable impurities.

Abstract: This method is a method for manufacturing a gas turbine blade, including: producing a gas turbine blade having a cooling pass inside thereof; and partially coating an inner surface of the cooling pass with Al. The step of partially coating an inner surface of the cooling pass with Al further including: a first step of specifying a temperature range which satisfies both of oxidation resistance and fatigue strength and the temperature distribution of the inner surface of the cooling pass based on an examination result or result of a numerical analysis; a second step of setting an Al-coating-applying portion of the inner surface of the cooling pass as the temperature range specified at the first step; and a third step of applying Al coating only into the set Al-coating-applying portion.

Abstract: Provided herein are an austenite steel that satisfies desirable strength and desirable castability at the same time, and an austenite steel casting using same. The austenite steel according to an embodiment of the present invention contains Ni: 25 to 50%, Nb: 3.8 to 6.0%, Zr: 0.5% or less, B: 0.001 to 0.05%, Cr: 12 to 25%, Ti: 1.6% or less, Mo: 4.8% or less, and W: 5.2% or less in mass %, and the balance Fe and unavoidable impurities, wherein the parameter Ps represented by the following formula (1) satisfies Ps?38, Ps=8.3[Nb]?7.5[Ti]+2.4[Mo]+3.5[W]??formula (1), where [Nb], [Ti], [Mo], and [W] represent the contents of Nb, Ti, Mo, and W, respectively, in mass %.