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 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 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: 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: An Ni base forged alloy is easy to make hot forging and miniaturization of crystal grains while excellent high-temperature strength and segregation property are compatible. The Ni base forged alloy has solid solution temperature of a precipitation strengthening phase lower than or equal to 970° C., difference in the solid solution temperature between a ?-phase and the precipitation strength phase larger than or equal to 50° C., Al of 0.5 to 1.0%, Cr of 17 to 21%, Fe of 17 to 19%, Nb of 4.5 to 5.5%, Ti of 0.8 to 1.3%, W of 3.0 to 6.0%, B of 0.001 to 0.03%, C of 0.001 to 0.1% and Mo of 1.0% or less in mass percentage [%] and remainder made of Ni and inevitable impurities.

Abstract: To provide, in producing a large product through casting, a Ni-based alloy with a composition that minimizes variations in strength at different locations even when the solidification rate becomes slow and the amount of micro segregation increases. The Ni-based casting alloy of the present invention has a composition of, in mass %, 0.001% to 0.1% C, 15% to 23% Cr, 0% to 11.5% Mo, 3% to 18% W, 5 or less % Fe, 10 or less % Co, 0.4 or less % Ti, 0.4 or less % Al, and Nb and Ta (where 0.5%?Nb+Ta?4.15%), in which 7%?Mo+1/2W?13% is satisfied, and the composition also contains inevitable impurities and Ni.

Abstract: A heat resistant alloy member that maintains the creep strength and improves the fatigue characteristics is provided. The heat resistant alloy member according to the present invention includes a recrystallized structure layer including finer grains on the surface of the member than those inside of the member. The recrystallized structure layer is formed by forming a stirred layer by giving processing strain to the surface of the member using a friction stir processing, and applying recrystallization heat treatment to the stirred layer for recrystallization.

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: To provide, in producing a large product through casting, a Ni-based alloy with a composition that minimizes variations in strength at different locations even when the solidification rate becomes slow and the amount of micro segregation increases. The Ni-based casting alloy of the present invention has a composition of, in mass %, 0.001% to 0.1% C, 15% to 23% Cr, 0% to 11.5% Mo, 3% to 18% W, 5 or less % Fe, 10 or less % Co, 0.4 or less % Ti, 0.4 or less % Al, and Nb and Ta (where 0.5%?Nb+Ta?4.15%), in which 7%?Mo+1/2W?13% is satisfied, and the composition also contains inevitable impurities and Ni.

Abstract: An Ni base forged alloy is easy to make hot forging and miniaturization of crystal grains while excellent high-temperature strength and segregation property are compatible. The Ni base forged alloy has solid solution temperature of a precipitation strengthening phase lower than or equal to 970° C., difference in the solid solution temperature between a ?-phase and the precipitation strength phase larger than or equal to 50° C., Al of 0.5 to 1.0%, Cr of 17 to 21%, Fe of 17 to 19%, Nb of 4.5 to 5.5%, Ti of 0.8 to 1.3%, W of 3.0 to 6.0%, B of 0.001 to 0.03%, C of 0.001 to 0.1% and Mo of 1.0% or less in mass percentage [%] and remainder made of Ni and inevitable impurities.

Abstract: An Ni base alloy uses GTD-111 as a base to improve high-temperature strength while maintaining the weldability and corrosion resistance and a gas turbine blade utilizes the Ni base alloy. The Ni base alloy contains Al of 2.5 to 3.5%, Co of 1.5 to 5.5%, Cr of 11.8 to 13.8%, Mo of 0.4 to 1.4%, Ta of 3.0 to 5.0%, Ti of 5.1 to 6.1%, W of 3.3 to 4.3%, B of 0.01 to 0.02%, C of 0.08 to 0.12% in mass % and remainder containing Ni and inevitable impurities and does not substantially contain Nb.

Abstract: An operation control method for a gas turbine includes making a molten salt map of molten salt for causing high-temperature corrosion on high-temperature components of the turbine due to impurities using a thermodynamic equilibrium calculation on the basis of the impurities contained in low-quality fuel and operation data of the gas turbine, indicating a surface temperature and a pressure of the high-temperature components of the turbine on the molten salt map , predicting a lifetime of the high-temperature components of the gas turbine by estimating a corrosion rate thereof, and controlling the flow rate of the low-quality fuel supplied to a combustor so that an area of surface temperature and pressure regions of the high-temperature components superposing on the region of molten salt in the liquid phase on the molten salt map is reduced.

Abstract: A Ni-base alloy large-size member comprises a base material having strip-shaped carbide segregation, and a homogeneous modified layer formed on a welding groove surface by treatment using Friction stir processing and solution treatment. In addition, a Ni-base alloy welded structure is manufactured by welding the Ni-base alloy large-size member with other member constituting the Ni-base alloy welded structure, such as a member formed of ferrite steel or another Ni-base alloy large-size member under the condition that weld penetration depth is shallower than the thickness of the modified layer.

Abstract: A heat resistant alloy member that maintains the creep strength and improves the fatigue characteristics is provided. The heat resistant alloy member according to the present invention includes a recrystallized structure layer including finer grains on the surface of the member than those inside of the member. The recrystallized structure layer is formed by forming a stirred layer by giving processing strain to the surface of the member using a friction stir processing, and applying recrystallization heat treatment to the stirred layer for recrystallization.

Abstract: It is an objective of the present invention to provide an effective use of the friction stir processing (FSP) technology for Ti-alloy turbine blades with a long radial length, and provide a Ti-alloy turbine blade having both high erosion resistance and high long term reliability. There is provided a turbine blade made of an ?-? titanium alloy having an average Vickers hardness of 320 Hv or less, the turbine blade having a leading edge, in which: the turbine blade includes, at the leading edge thereof, a first hardened surface region having a thickness of from 0.5 to 3.0 mm and having an average Vickers hardness of 340 Hv or more; and the first hardened surface region is formed by friction stir processing a surface region of the leading edge of the turbine blade.

Abstract: An operation control method for a gas turbine comprising the steps of: making a molten salt map in a liquid phase state by calculating a dew point and a solidus temperature of molten salt for causing high-temperature corrosion on high-temperature components of the turbine due to impurities using a thermodynamic equilibrium calculation on the basis of the impurities contained in low-quality fuel and operation data of the gas turbine, indicating a surface temperature and a pressure of the high-temperature components of the turbine on the molten salt map to determine a superposition state thereof on a region of molten salt in a liquid phase, predicting a lifetime of the high-temperature components of the gas turbine by estimating a corrosion rate thereof, and controlling the flow rate of the low-quality fuel supplied to a combustor on the basis of the prediction of the lifetime of the high-temperature components so that an area of surface temperature and pressure regions of the high-temperature components superp

Abstract: A hydrogen-resistant high strength material made of a Ni-based alloy or an Fe—Ni-based alloy includes an aged portion and a hydrogen embrittlement suppressing layer that is to be exposed to hydrogen. The hydrogen embrittlement suppressing layer has a hydrogen embrittlement index of not less than 0.9, wherein the hydrogen embrittlement index is defined as a ratio of an elongation after hydrogen charging in relation to an elongation before hydrogen charging. The aged portion has a tensile strength exceeding 1000 MPa.