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: A high-temperature steam turbine plant is of the top turbine type and structured as follows. It comprises a boiler building including a vertical boiler on the top of which a VHT turbine is installed; and a turbine building installed on the ground as a base. The VHT turbine and a generator connected with it are installed on the top of the boiler. The material for the portion of the steam pipe between the boiler building and the turbine building which is exposed to highest steam pressure is austenite steel which contains 50 weight % or more of ferrite steel or Fe. The inlet temperature of the VHT turbine is 675° C. or more and its outlet temperature is 550° C. or more and 650° C. or less.

Abstract: A Ni-based heat resistant alloy has a composition of, by mass percent, carbon: 0.001 to 0.1%, chromium: 16 to 22%, aluminum: 0.5 to 1.5%, molybdenum: 0.1 to 2.0%, tungsten: 0.1 to 6.0%, niobium: 3.5 to 5.5%, titanium: 0.8 to 3.0%, iron: 16 to 20%, and the balance being nickel and inevitable impurities. A parameter Ps indicating a segregation tendency is in a range of Ps??3.5. The parameter Ps is represented by Formula (1). Ps=1.05×Al content+0.6×Ti content?0.8×Nb content?0.

Abstract: A steam turbine valve has a valve seat, a valve rod or a valve body in which a 3 to 5 mm thick stellite sheet is welded to ferrite cast steel by friction-stir welding, and it is preferable that a stellite layer made of the stellite sheet welded by friction-stir welding is equiaxial crystal and cast structure is not included, that an inclusion of iron into the stellite layer up to 2 mm thick from the surface of the stellite layer in the direction of ferrite cast steel is 3% or less by weight, and that a dilution layer formed between the stellite layer and the ferrite cast steel is 1 to 2 mm thick.

Abstract: In a gas turbine blade where a part of the ?? phase precipitation strengthened type Ni-based alloy base material is composed of a weld metal, the weld metal is a Ni-based alloy containing Ta from 4.8 to 5.3 wt. %, Cr from 18 to 23 wt. %, Co from 12 to 17 wt. %, W from 14 to 18 wt. %, C from 0.03 to 0.1 wt. %, Mo from 1 to 2 wt. %, and Al of 1 wt. % or less, in which the oxygen content is 0 to 30 ppm, the Ti content from 0 to 0.1 wt. %, and the Re content from 0 to 0.5 wt. %. A blade base metal is manufactured by the step of stripping, the step of solution heat treatment where the ?? phase is dissolved again, the step of welding in an inert gas chamber by a TIG method using a welding wire where the weld metal can be obtained, the step of HIP treatment at 1100° C. to 1150° C., and the step of an aging treatment at 835° C. to 855° C.

Abstract: A Ni—Fe based super alloy having high strength and toughness at high temperatures even when used in high-temperature environments, and a process of producing the super alloy. A turbine disk using the super alloy, a process of producing the turbine disk, a turbine spacer using the super alloy, and a process of producing the turbine spacer, as well as a gas turbine are also provided. The Ni—Fe based super alloy contains not more than 0.03% by weight of C, 14-18% of Cr, 15-45% of Fe, 0.5-2.0% of Al, not more than 0.05% of N, 0.5 to 2.0% of Ti, 1.5-5.0% of Nb, and Ni as a main ingredient.

Abstract: It is an object of the present invention to provide an Ni based alloy for forging having high forging-related characteristics with a wide temperature range for high-temperature forging and high upper forging temperature limit. An Ni based alloy for forging, containing Cr at 12 to 20%, Al at 3.5 to 5%, Co at 15 to 23%, W at 5 to 12%, C at 0.001 to 0.05%, and Nb, Ti and Ta at a total content of 0.5 to 1.0%, all percentages by mass, and a steam turbine plant component using the same.

Abstract: To provide a steam turbine rotor and a steam turbine which are highly reliable. The steam turbine rotor is characterized in that a forged material B having a hollow structure is joined to a forged material A of a Ni group super-alloy by welding, and weld back waves on an inner surface are removed, and the inner surface is smoothed, and a forging material C and a forging material B are joined to each other with a bolt.

Abstract: It is an object to provide a friction stir tool excellent in productivity, high temperature strength, and wear resistance at high temperatures. The friction stir tool is formed of a Co-based alloy comprising crystal grains containing a ?? precipitate phase dispersed and precipitated therein, and a crystal grain boundary region and a precipitate phase between adjacent crystal grains, in which the precipitate phase is at least one phase selected from a ? phase, a Laves phase and a carbide phase.

Abstract: A nickel base alloy includes: by mass, 0.001 to 0.1% of carbon; 12 to 23% of chromium; 15 to 25% of cobalt; 3.5 to 5.0% of aluminum; 4 to 12% of molybdenum; 0.1 to 7.0% of tungsten; and a total amount of Ti, Ta and Nb being not more than 0.5%. A parameter Ps represented by a formula (1) shown below is 0.6 to 1.6, Ps=?7×[C]?0.1×[Mo]+0.5×[Al]??(1) where [C] indicates an amount of carbon; [Mo] indicates an amount of molybdenum; and [Al] indicates an amount of aluminum, by mass percent.

Abstract: A Ni based cast alloy consisting essentially of C: 0.01 to 0.2% by weight, Si: 0.5 to 4.0% by weight, Cr: 14 to 22% by weight, Mo+W: 4.0 to 10% by weight, B: 0.001 to 0.02% by weight, Co: up to 10% by weight, Al: up to 0.5% by weight, Ti: up to 0.5% by weight, Nb: up to 5.0% by weight, Fe: up to 10% by weight, the balance being Ni and incidental impurities, wherein a ?? phase precipitates in a matrix phase thereof.

Abstract: In a gas turbine blade where a part of the ?? phase precipitation strengthened type Ni-based alloy base material is composed of a weld metal, the weld metal is a Ni-based alloy containing Ta from 4.8 to 5.3 wt. %, Cr from 18 to 23 wt. %, Co from 12 to 17 wt. %, W from 14 to 18 wt. %, C from 0.03 to 0.1 wt. %, Mo from 1 to 2 wt. %, and Al of 1 wt. % or less, in which the oxygen content is 0 to 30 ppm, the Ti content from 0 to 0.1 wt. %, and the Re content from 0 to 0.5 wt. %. A blade base metal is manufactured by the step of stripping, the step of solution heat treatment where the ?? phase is dissolved again, the step of welding in an inert gas chamber by a TIG method using a welding wire where the weld metal can be obtained, the step of HIP treatment at 1100° C. to 1150° C., and the step of an aging treatment at 835° C. to 855° C.

Abstract: The invention provides a Ni—Fe-based alloy which is preferable for a welding of a joint between different materials such as a steel material and a Ni-based alloy, and a rotor for a steam turbine which is manufactured by using the same. The invention employs a Ni—Fe-based alloy comprising Cr: 14 to 18%, Al: 1.0 to 2.5%, Mo+W: 2.5 to 5.0%, C: 0.01 to 0.10%, B: 0.001 to 0.03%, and Fe: 15 to 20%, in mass, in which the remaining portion is constructed by an unavoidable impurity and Ni, as a welding metal. As a result, it is possible to provide a rotor for a steam turbine which can hold down a reduction of a ductility and a toughness generated in the case of welding the different materials, and is excellent in a strength and the ductility.

Abstract: Disclosed are a high-strength Ni-base alloy, a method of producing the Ni-base alloy, and a method of recovering a member made of a degraded Ni-base alloy. It contains not more than 0.1 wt % C, not more than 50 wt % Fe, not more than 30 wt % Cr, Ti, and at least one of Nb and Al. It has been strengthened by precipitates of a ?? phase (Ni3Al) and/or a ?? phase (Ni3Nb). It contains also a ? phase (Ni3Ti) which is thermodynamically stable in a temperature range of 800° C. to 900° C. When observed a cross-section of the Ni-base alloy, a plurality of nodes exist along each segment connecting two meeting points each of which point is defined by adjacent three crystal grains, and precipitates of the ?? phase and/or the ?? phase in each of crystal grains of the Ni-base alloy have an average particle size of not more than 100 nm.

Abstract: Disclosed is a low-thermal-expansion Ni-based super-heat-resistant alloy for a boiler, which has excellent high-temperature strength. The alloy can be welded without the need of carrying out any aging treatment. The alloy has a Vickers hardness value of 240 or less. The alloy comprises (by mass) C in an amount of 0.2% or less, Si in an amount of 0.5% or less, Mn in an amount of 0.5% or less, Cr in an amount of 10 to 24%, one or both of Mo and W in such an amount satisfying the following formula: Mo+0.5 W=5 to 17%, Al in an amount of 0.5 to 2.0%, Ti in an amount of 1.0 to 3.0%, Fe in an amount of 10% or less, and one or both of B and Zr in an amount of 0.02% or less (excluding 0%) for B and in an amount of 0.2% or less (excluding 0%) for Zr, with the remainder being 48 to 78% of Ni and unavoidable impurities.

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.

Abstract: The present invention provides, in a ?? phase precipitation strengthening type Ni-base alloy, an alloy excellent in heat treatment capability and weldability and suitable for joint with a ferritic steel. Further, the present invention provides a welded turbine rotor having the strength, ductility, and toughness simultaneously over the whole welded structure when a precipitation strengthening type Ni-base alloy having a heatproof temperature of 675° C. or higher is joined to a ferritic steel. A Ni-base alloy according to the present invention contains cobalt, chromium, aluminum, carbon, boron, and at least either tungsten or molybdenum with the remainder being nickel and inevitable impurities, having an alloy composition including 12 to 25 percent by mass of Co, 10 to 18 percent by mass of Cr, 2.0 to 3.6 percent by mass of Al, 0.01 to 0.15 percent by mass of C, 0.001 to 0.03 percent by mass of B, the total amount of tungsten and molybdenum being 5.0 to 10 percent by mass.

Abstract: A Ni-based alloy member has resistance against grain boundary fracture, fatigue strength, and oxidation resistance at temperatures near 1000° C. or higher. The Ni-based alloy member includes a non-repaired region made of a Ni-based alloy base and a region repaired by welding, which is formed on the non-repaired region and which is made of a buildup-welded layer, the buildup-welded layer being made of a Ni-based alloy containing, by weight, 15% or less of Co, 18-22% of Cr, 0.8-2.0% of Al, 5.0% or less of Ta, 0.5% or less of Mo, 0.5% or less of Ti, 13-18% of W, 0.05-0.13% of C, 0.06% or less of Zr, 0.015% or less of B, 0.4-1.2% of Mn, and 0.1-0.3% of Si, the balance of the alloy being preferably essentially made of Ni.

Abstract: A Ni-based alloy member has resistance against grain boundary fracture, fatigue strength, and oxidation resistance at temperatures near 1000° C. or higher. The Ni-based alloy member includes a non-repaired region made of a Ni-based alloy base and a region repaired by welding, which is formed on the non-repaired region and which is made of a buildup-welded layer, the buildup-welded layer being made of a Ni-based alloy containing, by weight, 15% or less of Co, 18-22% of Cr, 0.8-2.0% of Al, 5.0% or less of Ta, 0.5% or less of Mo, 0.5% or less of Ti, 13-18% of W, 0.05-0.13% of C, 0.06% or less of Zr, 0.015% or less of B, 0.4-1.2% of Mn, and 0.1-0.3% of Si, the balance of the alloy being preferably essentially made of Ni.

Abstract: A nickel (Ni) based alloy for forging includes: 0.001 to 0.1 wt. % of carbon (C); 12 to 23 wt. % of chromium (Cr); 3.5 to 5.0 wt. % of aluminum (Al); 5 to 12 combined wt. % of tungsten (W) and molybdenum (Mo) in which the Mo content is 5 wt. % or less; a negligible small amount of titanium (Ti), tantalate (Ta) and niobium (Nb); and the balance of Ni and inevitable impurities.