Hitachi, Ltd.

Mitsubishi Hitachi Power Systems, Ltd.

Hideo Yoda

Masahiko Arai

Hiroyuki Doi

Shinji Oikawa

Takeshi Kudo

Kiyoshi Namura

Yutaka Yamashita

Eiji Saitou

Koki Sato

Kazuo Ikeuchi

Masakazu Takasumi

Hirotsugu Kawanaka

Kunio Asai

Keiko Shishime

Atsuya Hirano

Shuhei Nogami

Kennichi Murata

Kazuto Mikazuki

Masato Machida

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.

Steam turbine rotor blade and method for manufacturing steam turbine rotor blade

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&#x2266;[Ti content]&#x2266;2.5' and '0.5&#x2266;[Al content]+2[C content]&#x2266;2.7'.

Precipitation hardening martensitic stainless steel and steam turbine component made thereof

A burnishing device and method are provided that enable burnishing processing to be reliably performed on a surface included in an object to be processed and having a change in height and inclination angle. The device includes a burnishing tool having a pressing unit that rotationally presses a surface of an object to be processed, the surface having a change in height and inclination angle; a tool driving device configured to move the burnishing tool; a strain sensor configured to detect the strain amount of the burnishing tool; and a computer that calculates pressing force to be applied by the pressing unit in a normal direction of the surface of the object to be processed, calculates correction amount of displacement of the tool driving device in a pressing direction based on calculated pressing force and stored pressing force in advance, and outputs the correction amount to the tool driving device.

Burnishing device and burnishing method using it

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.

Precipitation hardening martensitic stainless steel, and steam turbine long blade, steam turbine, and power plant using the same

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.

Precipitate hardening stainless steel and long blade using same for steam turbine

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.

Precipitation hardenable martensitic stainless steel and steam turbine blade using the same

A turbine rotor blade which is enhanced in erosion resistance and reduced in stress corrosion cracking sensitivity is provided. When a blade tip end of the turbine rotor blade is hardened by heat treatment, hardness at an outer circumferential side in a radial direction is made higher than hardness at an inner circumferential side, and thereby, enhancement in erosion resistance and reduction in stress corrosion cracking sensitivity are made compatible with each other all over in a blade length direction.

Turbine rotor blade

A steam turbine blade in which the turbine blade has a blade root of the axially-inserted fir tree type and a larger number of turbine blades can be attached in a restricted outer peripheral region of a turbine rotor by arranging the blade root to be oriented in a direction forming a predetermined angle &#x3b1; larger than 0&#xb0; relative to the axial direction of the turbine rotor. The steam turbine blade can suppress peak stresses generated at the bottoms of notches formed in the blade root and a blade groove and also suppress fretting fatigue from being induced by contact between peak stress generating areas and areas opposed to the peak stress generating areas at the notch bottoms. The steam turbine blade includes an airfoil, and a blade root attached to a turbine rotor and having plural stages of hooks in the radial direction of the turbine rotor.

Steam turbine blade, steam turbine rotor, steam turbine with those blades and rotors, and power plant with the turbines

The invention provides a heat resisting steel having superior high-temperature strength and notch rupture strength, a rotor shaft using the heat resisting steel, a steam turbine using the rotor shaft, and a power plant using the steam turbine. The heat resisting steel is made of a Cr&#x2014;Mo&#x2014;V low-alloy steel containing 0.15-0.40% by weight of C, not more than 0.5% of Si, 0.05-0.50% of Mn, 0.5-1.5% of Ni, 0.8-1.5% of Cr, 0.8-1.8% of Mo and 0.05-0.35% of V, and having a (Ni/Mn) ratio of 3.0-10.0.

Heat resisting steel, steam turbine rotor shaft using the steel, steam turbine, and steam turbine power plant

A turbine moving blade has a blade portion extending from the basal portion to the tip of the moving blade. The blade root portion is formed at the basal portion of the blade portion and engaged with a corresponding disk groove of a turbine rotor on a one-by-one basis, and the integral cover is formed at the tip of the blade portion integrally with the blade portion. The integral cover includes at least a pair of pressure and suction sloped surfaces inclined relative to the direction of the rotational axis of a turbine so as to restrain the elastic restoring force of the moving blade torsionally deformed at the time of installation of the moving blade by bringing the integral covers of mutually adjacent blades into contact.

Turbine moving blade

A set of turbine rotor blades is arranged on a rotor disk. Each rotor disk has blade profile, root parts which is fitted axially in an axial disk groove formed circumferenctially in the rotor disk, and an integral cover formed at the outer edge of the blade profile part. A front end surface, faced in a direction the rotor disk rotates, of the integral cover is inclined to a direction in which the root part of the turbine rotor blade is fitted in the disk groove of the rotor disk. The sum of circumferential lengths of the integral covers is greater than a circle at which the integral covers are joined to the blade profile parts. Adjacent integral covers are brought into contact with each other by the blade profile parts that are twisted when root parts of the turbine rotor blades are fitted axially in the disk grooves.

Growing community of inventors

Hitachi, Japan

Hideo Yoda