Abstract: An optical fiber-embedded PC steel strand includes a PC steel strand in which a plurality of PC steel wires are twisted together, and an optical fiber. The optical fiber is fixed with a resin in a twist groove that is a groove between two PC steel wires of the PC steel wires, the two PC steel wires being disposed at an outer surface of the PC steel strand and being next to each other. A coefficient of variation in distance between a common tangent of the two PC steel wires that form the twist groove and are next to each other, and a center of the optical fiber is 0.5 or less, as measured in 10 cross sections of the PC steel strand that are perpendicular to a longitudinal direction of the PC steel strand.

Abstract: There is provided a ferritic stainless steel which has a composition containing, in % by mass, C: 0.003 to 0.030%, Si: 0.01 to 1.00%, Mn: 0.05 to 0.30%, P: 0.050% or less, S: 0.020% or less, Cr: 24.0 to 30.0%, Ni: 1.50 to 3.00%, Mo: 1.00 to 3.00%, Al: 0.001 to 0.020%, Nb: 0.20 to 0.80%, and N: 0.030% or less, the balance being Fe and incidental impurities. The composition satisfies certain inequalities.

Abstract: According to the present invention, the steam turbine rotor includes an embedded fin which includes: a bent bottom part; and an upright part including a fin tip and a fin root, and which is inserted in a fixing groove and fixed in the fixing groove by means of a locking strip, and has an arrangement wherein a static friction coefficient between a side surface of the fixing groove and a side surface of the fin root, a static friction coefficient between a side surface of the locking strip and a side surface of the fin root, and a static friction coefficient between the side surface of the fixing groove and the side surface of the locking strip are increased.

Abstract: A steam turbine rotor blade achieving both abrasion resistance and reliability, and a method for manufacturing a steam turbine rotor blade capable of obtaining such a steam turbine rotor blade are provided. A steam turbine rotor blade according to the invention is characterized by including a blade base material and an erosion shield formed on a surface of the blade base material, wherein the blade base material is composed of a titanium alloy, and the erosion shield is composed of a weld overlay layer including a parent phase composed of pure titanium in which a metal element is solid-dissolved or a titanium alloy in which a metal element is solid-dissolved, and a hard phase dispersed in the parent phase.

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: A steam turbine rotor blade achieving both abrasion resistance and reliability, and a method for manufacturing a steam turbine rotor blade capable of obtaining such a steam turbine rotor blade are provided. A steam turbine rotor blade according to the invention is characterized by including a blade base material and an erosion shield formed on a surface of the blade base material, wherein the blade base material is composed of a titanium alloy, and the erosion shield is composed of a weld overlay layer including a parent phase composed of pure titanium in which a metal element is solid-dissolved or a titanium alloy in which a metal element is solid-dissolved, and a hard phase dispersed in the parent phase.

Abstract: A segment 31 for a sealing device according to the present invention is used in a sealing device 28 provided between a turbine rotor 12 and a stationary body 14 that covers the turbine rotor 12. The segment 31 for the sealing device is characterized by including a base 32 that engages with the turbine rotor 12 and a free-cutting layer 34 that covers a stationary body opposed surface 37, which is a surface of the base 32 opposed to the stationary body 14.

Abstract: It is an objective of the present invention to provide a precipitation-hardening martensitic stainless steel having well-balanced properties of high mechanical strength, high toughness and good corrosion resistance properties. There is provided a precipitation-hardening martensitic stainless steel comprising: 0.10 mass % or less of C; 13.0 to 15.0 mass % of Cr; 7.0 to 10.0 mass % of Ni; 2.0 to 3.0 mass % of Mo; 0.5 to 2.5 mass % of Ti; 0.5 to 2.5 mass % of Al; 0.5 mass % or less of Si; 0.1 to 1.0 mass % of Mn; and the balance including Fe and incidental impurities, in which the mass % content of the Ti (represented by [Ti content]), the mass % content of the Al (represented by [Al content]) and the mass % content of the C (represented by [C content]) satisfy relationships of “0.5?[Ti content]?2.5” and “0.5?[Al content]+2[C content]?2.7”.

Abstract: The problem to be solved of the present invention is to provide a precipitation hardening martensitic stainless steel having excellent tissue stability, strength, toughness, and corrosion-resistance, requiring no sub-zero treatment, and having excellent productivity; and also a steam turbine long blade using the same. The problem is solved by providing a precipitation hardening martensitic stainless steel containing, by mass, 0.1% or less of C; 0.1% or less of N; 9.0% or more and 14.0% or less of Cr; 9.0% or more and 14.0% or less of Ni; 0.5% or more and 2.5% or less of Mo; 0.5% or less of Si; 1.0% or less of Mn; 0.25% or more and 1.75% or less of Ti; 0.25% or more and 1.75% or less of Al, and the rest is Fe and inevitable impurities; and a steam turbine long blade using the precipitation hardening martensitic stainless steel.

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: It is an object of the present invention to provide a sealing mechanism that, while preventing a clearance that passes in an axial direction through an entire abutting surface without involving large resistance and that invites blow-by of a working fluid, can prevent adjacent seal segments from sticking to each other, and a method for manufacturing the sealing mechanism. A sealing device includes: an annular sealing ring that includes a plurality of seal segments annularly juxtaposed; a plurality of seal fins provided in an axial direction on an inner peripheral surface of the sealing ring; a joint surface on a circumferential end of the seal segment, the joint surface facing a joint surface on an adjacent seal segment; a groove that extends in a radial direction in the joint surface; and a protrusion formed by bending part of a surface that constitutes a long side of the groove toward an outside of the joint surface.

Abstract: There is provided a steam turbine rotor with high reliability and corresponding to increase in length of a high strength steel blade, in which only a low-pressure last stage is highly strengthened. The steam turbine rotor includes a steam turbine low-pressure last stage long blade made of a precipitation hardening type martensitic stainless steel containing, in mass, 0.1% or less of C, 0.1% or less of N, 9.0% to 14.0% inclusive of Cr, 9.0% to 14.0% inclusive of Ni, 0.5% to 2.5% inclusive of Mo, 0.5% or less of Si, 1.0% or less of Mn, 0.25% to 1.75% inclusive of Ti, 0.25% to 1.75% inclusive of Al, and the balance consisting of Fe and inevitable impurities, and a disk having a specific alloy composition is joined to a last stage section of the turbine rotor made of a low-alloy steel.

Abstract: As a precipitate hardening stainless steel has excellent structure stability, strength, toughness, and corrosion resistance, requires no sub-zero treating and is excellent in terms of productivity, a long blade for a steam turbine uses the same. The following are provided: a precipitate hardening stainless steel, which comprises C at 0.05 mass % or less, N at 0.05 mass % or less, Cr at 10.0 mass % to 14.0 mass %, Ni at 8.5 mass % to 11.5 mass %, Mo at 0.5 mass % to 3.0 mass %, Ti at 1.5 mass % to 2.0 mass %, Al at 0.25 mass % to 1.00 mass %, Si at 0.5 mass % or less, and Mn at 1.0 mass % or less, and the balance is composed of Fe and inevitable impurities. The long blade for a steam turbine is composed of this precipitate hardening stainless steel.

Abstract: It is an objective of the invention to provide a precipitation-hardening martensitic stainless steel having a far better balance between a high mechanical strength and a high toughness than conventional ones as well as having good corrosion resistance properties. There is provided a precipitation-hardening martensitic stainless steel throughout which precipitates of intermetallic compounds are dispersed, the martensitic stainless steel including: 0.1 mass % or less of C; 11 to 13 mass % of Cr; 7.5 to 11 mass % of Ni; 0.9 to 1.7 mass % of Al; 0.85 to 1.35 mass % of Mo; 1.75 to 2.75 mass % of W; and the balance including Fe and inevitable impurities, in which “[Mo content]+0.5×[W content]” is from 1.9 mass % to 2.5 mass %, and “[Mo content]/[W content]” is from 0.4 to 0.6.

Abstract: A precipitation hardenable martensitic stainless steel excellent in the stability of martensite, having the high strength, high toughness and high corrosion resistance is provided. The precipitation hardenable martensitic stainless steel contains at a mass rate, C: 0.05-0.10%, Cr: 12.0-13.0%, Ni: 6.0-7.0%, Mo: 1.0-2.0%, Si: 0.01-0.05%, Mn: 0.06-1.0%, Nb: 0.3-0.5%, V: 0.3-0.5%, Ti: 1.5-2.5%, Al: 1.0-2.3%, and the remainder consisting of Fe and an unavoidable impurity.

Abstract: A precipitation hardening martensitic stainless steel is provided with excellent mechanical property and corrosion resistance and contains, by mass, 0.1% or less of C; 0.1% or less of N; 10.0%˜15.0% of Cr; 10.0%˜15.0% of Ni; 0.5%˜2.5% of Mo; 1.0%˜3.0% of Al; 1.0% or less of Si; 1.0% or less of Mn, and the rest is Fe and inevitable impurities. A steam turbine long blade is made of the precipitation hardening martensitic stainless steel.

Abstract: This invention provides a precipitate hardening stainless steel having excellent structure stability, strength, toughness, and corrosion resistance, which requires no sub-zero treating and thus is excellent in terms of productivity, and a long blade for a steam turbine using the same. The following are provided: a precipitate hardening stainless steel, which comprises C at 0.05 mass % or less, N at 0.05 mass % or less, Cr at 10.0 mass % to 14.0 mass %, Ni at 8.5 mass % to 11.5 mass %, Mo at 0.5 mass % to 3.0 mass %, Ti at 1.5 mass % to 2.0 mass %, Al at 0.25 mass % to 1.00 mass %, Si at 0.5 mass % or less, and Mn at 1.0 mass % or less, and the balance is composed of Fe and inevitable impurities; and a long blade for a steam turbine composed of the precipitate hardening stainless steel.

Abstract: It is an objective of the present invention to provide a precipitation-hardening martensitic stainless steel having well-balanced properties of high mechanical strength, high toughness and good corrosion resistance properties. There is provided a precipitation-hardening martensitic stainless steel comprising: 0.10 mass % or less of C; 13.0 to 15.0 mass % of Cr; 7.0 to 10.0 mass % of Ni; 2.0 to 3.0 mass % of Mo; 0.5 to 2.5 mass % of Ti; 0.5 to 2.5 mass % of Al; 0.5 mass % or less of Si; 0.1 to 1.0 mass % of Mn; and the balance including Fe and incidental impurities, in which the mass % content of the Ti (represented by [Ti content]), the mass % content of the Al (represented by [Al content]) and the mass % content of the C (represented by [C content]) satisfy relationships of “0.5?[Ti content]?2.5” and “0.5?[Al content]+2[C content]?2.7”.

Abstract: A precipitation hardenable martensitic stainless steel excellent in the stability of martensite, having the high strength, high toughness and high corrosion resistance is provided. The precipitation hardenable martensitic stainless steel contains at a mass rate, C: 0.05-0.10%, Cr: 12.0-13.0%, Ni: 6.0-7.0%, Mo: 1.0-2.0%, Si: 0.01-0.05%, Mn: 0.06-1.0%, Nb: 0.3-0.5%, V: 0.3-0.5%, Ti: 1.5-2.5%, Al: 1.0-2.3%, and the remainder consisting of Fe and an unavoidable impurity.

Abstract: A motion toy body consisting of a trunk containing a housing therein, and a head; a frame in the housing which can be vertically moved, and which supports a crankshaft on which left and right feet are mounted so that the feet can be moved forward and backward; a slide shaft supported by a frame so that the slide shaft can be moved axially and turned, and which has a change-over gear, adapted to engage and disengage from a foot-driving gear by which power is transmitted to the crankshaft, and a singing gear; a screw on the outer circumferential surface of the slide shaft; a support member fixed to a bottom member of the housing and having a feed screw adapted to be engaged with and disengaged from the screw on the slide shaft and thereby move the slide shaft when the feed screw is engaged with the screw on the slide shaft; a spring fitted around the slide shaft for urging the slide shaft constantly toward the support member; an electric motor fixed to the frame and adapted to turn the slide shaft; a spring pro