Abstract: A method for evaluating a crack in a metal member comprises a first removal step (S10) and a second removal step (S20). In the first removal step (S10), a step for electrolyzing a metal member having an oxide scale formed on a surface thereof, a step for acquiring an image of the oxide scale as a first image, and a step for determining whether or not a scale crack has occurred are repeated until occurrence of a scale crack is determined. In the second removal step (S20), a step for electrolyzing the metal member having the scale crack, a second image acquisition step for acquiring an image of the oxide scale as a second image, and a second determination step for determining whether or not the scale crack has disappeared are repeated until disappearance of the oxide scale is determined.

Abstract: A method for evaluating a crack in a metal member comprises a first removal step (S10) and a second removal step (S20). In the first removal step (S10), a step for electrolyzing a metal member having an oxide scale formed on a surface thereof, a step for acquiring an image of the oxide scale as a first image, and a step for determining whether or not a scale crack has occurred are repeated until occurrence of a scale crack is determined. In the second removal step (S20), a step for electrolyzing the metal member having the scale crack, a second image acquisition step for acquiring an image of the oxide scale as a second image, and a second determination step for determining whether or not the scale crack has disappeared are repeated until disappearance of the oxide scale is determined.

Abstract: A faulted condition determination method is designed to detect a chromium content and a nickel content in a predetermined boundary region proximate to a boundary between a high-strength ferrite steel and a weld material in a welded joint in which the high-strength ferrite steel and another steel are welded together using the weld material containing nickel and to thereby determine the faulted condition of the predetermined boundary region based on the chromium content and the nickel content. Accordingly, it is possible to appropriately determine the faulted condition of welding of a replacement part in which a high-strength ferrite steel and another steel are welded together using a nickel-based weld material.

Abstract: A gas turbine disk material according to the present invention contains: C: from 0.05 to 0.15%; Ni: from 0.25 to 1.50%; Cr: from 9.0 to 12.0%; Mo: from 0.50 to 0.90%; W: from 1.0 to 2.0%; V: from 0.10 to 0.30%; Nb: from 0.01 to 0.10%; Co: from 0.01 to 4.0%; B: from 0.0005 to 0.010%; N: from 0.01 to 0.05%; Mn: 0.40% or less; Si: 0.10% or less; and Al: 0.020% or less. A balance is of Fe and unavoidable impurities. Additionally, as a heat treatment method, a quenching temperature of a forged material having the component composition is set within a range from 1050 to 1150° C.

Abstract: A method for manufacturing a shaft body by welding a plurality of shaft members together and forming the shaft body, the method including: a primary tempering step of subjecting a range in at least one of the shaft members, which is in the vicinity of an end of another shaft member side adjacent thereto, to tempering before the shaft members are welded together so that a strength of an end side of a region thereof is lower than a strength at a side which is opposite to the end of the region thereof; a welding step of welding the shaft members together after the primary tempering step; and a secondary tempering step of tempering the vicinity of a weld part between the shaft members after the welding step.

Abstract: A faulted condition determination method is designed to detect a chromium content and a nickel content in a predetermined boundary region proximate to a boundary between a high-strength ferrite steel and a weld material in a welded joint in which the high-strength ferrite steel and another steel are welded together using the weld material containing nickel and to thereby determine the faulted condition of the predetermined boundary region based on the chromium content and the nickel content. Accordingly, it is possible to appropriately determine the faulted condition of welding of a replacement part in which a high-strength ferrite steel and another steel are welded together using a nickel-based weld material.

Abstract: The precipitation hardened martensitic stainless steel is characterized by containing, in percent by weight, 12.25 to 14.25% Cr, 7.5 to 8.5% Ni, 1.0 to 2.5% Mo, 0.05% or less C, 0.2% or less Si, 0.4% or less Mn, 0.03% or less P, 0.005% or less S, 0.008% or less N, 0.90 to 2.25% Al, the balance substantially being Fe, and the total content of Cr and Mo being 14.25 to 16.75%. A turbine moving blade and a steam turbine are manufactured by using this martensitic stainless steel.

Abstract: A lithium-ion secondary battery including a negative electrode including negative-electrode active-material particles including an element being capable of sorbing and desorbing lithium ions, and being capable of alloying with lithium; or/and an elementary compound including an element that is capable of alloying with lithium; a positive electrode including a positive-electrode active material that enables Li ions to be sorbed therein and desorbed therefrom; and an electrolytic solution made by dissolving an electrolyte in a solvent. The negative-electrode active-material particles include particles whose particle diameter is 1 ?m or more in an amount of 85% by volume or more thereof when the entirety of said negative-electrode active-material particles, which are included in said negative electrode, is taken as 100% by volume, and the negative-electrode active-material particles exhibit a “D10” being 3 ?m or more. The solvent in the electrolytic solution includes a fluorinated ethylene carbonate.

Abstract: A negative-electrode material has negative-electrode active-material particles including: an element being capable of sorbing and desorbing lithium ions, and being capable of undergoing an alloying reaction with lithium; or/and an elementary compound being capable of undergoing an alloying reaction with lithium. The negative-electrode active-material particles includes particles whose particle diameter is 1 ?m or more in an amount of 85% by volume or more of them when the entirety is taken as 100% by volume, exhibit a BET specific surface area that is 6 m2/g or less, and exhibits a “D50” that is 4.5 ?m or more.

Abstract: A negative electrode for lithium-ion secondary battery including a negative electrode that includes a current collector; and a negative-electrode active-material layer formed on a surface of the current collector, and including negative-electrode active-material particles. The negative-electrode active-material particles include an element being capable of sorbing and desorbing lithium ions, and being capable of undergoing an alloying reaction with lithium; or/and an elementary compound being capable of undergoing an alloying reaction with lithium, the negative-electrode active-material particles include particles whose particle diameter is 1 ?m or more in an amount of 85% by volume or more thereof when the entirety is taken as 100% by volume, and exhibit a “D10” being 3 ?m or more. The negative-electrode active-material layer having a thickness that is 1.4 times or more of a “D90” that said negative-electrode active-material particles exhibit.

Abstract: A method for manufacturing a shaft body by welding a plurality of shaft members together and forming the shaft body, the method including: a primary tempering step of subjecting a range in at least one of the shaft members, which is in the vicinity of an end of another shaft member side adjacent thereto, to tempering before the shaft members are welded together so that a strength of an end side of a region thereof is lower than a strength at a side which is opposite to the end of the region thereof; a welding step of welding the shaft members together after the primary tempering step; and a secondary tempering step of tempering the vicinity of a weld part between the shaft members after the welding step.

Abstract: A first measured value of a specific physical quantity at a target portion is correlated with a damage evaluation index to calculate a damage degree corresponding to the first measured value. The specific physical quantity is measured at least once at a position corresponding to the first measurement position in another time period having a different usage elapsed time from that of the first measurement, and these second and subsequent measured values are correlated with damage degrees calculated based on temporal changes corresponding to the second and subsequent measurements. A new damage evaluation index is approximately calculated based on a relationship between the first, second, and subsequent measured values and the damage degrees corresponding to the first, second, and subsequent measured values.

Abstract: A negative-electrode stuff has negative-electrode active-material particles including: an element being capable of sorbing and desorbing lithium ions, and being capable of undergoing an alloying reaction with lithium; or/and an elementary compound being capable of undergoing an alloying reaction with lithium. The negative-electrode active-material particles includes particles whose particle diameter is 1 ?m or more in an amount of 85% by volume or more of them when the entirety is taken as 100% by volume, exhibit a BET specific surface area that is 6 m2/g or less, and exhibits a “D50” that is 4.5 ?m or more.

Abstract: A negative-electrode stuff has negative-electrode active-material particles including: an element being capable of sorbing and desorbing lithium ions, and being capable of undergoing an alloying reaction with lithium; or/and an elementary compound being capable of undergoing an alloying reaction with lithium. The negative-electrode active-material particles includes particles whose particle diameter is 1 ?m or more in an amount of 85% by volume or more of them when the entirety is taken as 100% by volume, exhibit a BET specific surface area that is 6 m2/g or less, and exhibits a “D50” that is 4.5 ?m or more.

Abstract: To provide a lithium ion secondary battery electrode in which a coated layer is held on a surface of an active material layer over a long period of time to suppress decomposition of the electrolysis solution and to enhance the cyclability, a manufacturing process for the same, and a lithium ion secondary battery using the electrode. A lithium ion secondary battery electrode includes a current collector, an active material layer containing a binder formed on a surface of the current collector, and a coated layer formed on the surface of at least a part of the active material layer, wherein the coated layer is an acrylic type copolymer cured substance including an acrylic type main chain and a side chain having polyester or polyether graft-polymerized to the acrylic type main chain and the coated layer is chemically bonded with the binder.

Abstract: To provide a lithium ion secondary battery electrode in which a coated layer is held on a surface of an active material layer over a long period of time to suppress decomposition of the electrolysis solution and to enhance the cyclability, a manufacturing process for the same, and a lithium ion secondary battery using the electrode. A lithium ion secondary battery electrode includes a current collector, an active material layer containing a binder formed on a surface of the current collector, and a coated layer formed on the surface of at least a part of the active material layer, wherein the coated layer contains a silicone-acrylic graft copolymer cured substance including an acrylic type main chain having a functional group and a side chain having a silicone graft-polymerized to the acrylic type main chain, and the coated layer is chemically bonded with the binder.

Abstract: To provide a lithium ion secondary battery electrode in which a coat is held on a surface of an active material layer over a long period of time to suppress decomposition of the electrolysis solution and to enhance the cyclability, a manufacturing process for the same, and a lithium ion secondary battery using the electrode. A lithium ion secondary battery electrode includes a current collector, an active material layer containing a binder formed on a surface of the current collector, and a coat containing modified polydimethylsiloxane formed on a surface of at least a part of the active material layer, wherein the coat is chemically bonded with the binder.

Abstract: The precipitation hardened martensitic stainless steel is characterized by containing, in percent by weight, 12.25 to 14.25% Cr, 7.5 to 8.5% Ni, 1.0 to 2.5% Mo, 0.05% or less C, 0.2% or less Si, 0.4% or less Mn, 0.03% or less P, 0.005% or less S, 0.008% or less N, 0.90 to 2.25% Al, the balance substantially being Fe, and the total content of Cr and Mo being 14.25 to 16.75%. A turbine moving blade and a steam turbine are manufactured by using this martensitic stainless steel.

Abstract: This method for setting aging conditions is provided with: a step for acquiring a master curve (20) indicating the relationship between an aging condition parameter and a material strength parameter by executing an aging process on a standard material; a step for acquiring a fitting point (A) indicating the value of the material strength parameter of a subject material of which the chemical component parameters and/or metal structure parameters differ from those of the standard material; a step for acquiring a corrected aging curve (30) by correcting the master curve (20) in a manner so that a portion of the master curve (20) corresponds to the fitting point (A); and a step for setting aging conditions for the subject material on the basis of the corrected aging curve (30).

Abstract: A first measured value of a specific physical quantity at a target portion is correlated with a damage evaluation index to calculate a damage degree corresponding to the first measured value. The specific physical quantity is measured at least once at a position corresponding to the first measurement position in another time period having a different usage elapsed time from that of the first measurement, and these second and subsequent measured values are correlated with damage degrees calculated based on temporal changes corresponding to the second and subsequent measurements. A new damage evaluation index is approximately calculated based on a relationship between the first, second, and subsequent measured values and the damage degrees corresponding to the first, second, and subsequent measured values.