Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Metals, Ltd.

Hitachi Astemo Ltd.

Hitachi Cable, Inc.

Hitachi Industrial Equipment Systems Co., Ltd.

Matahiro Komuro

Yuichi Satsu

Takao Imagawa

Hiroshi Fukui

Moriaki Fuyama

Hiroyuki Suzuki

Yuzo Kozono

Yoshiaki Kawato

Takashi Yasuhara

Yutaka Matsunobu

Yohji Maruyama

Tomohiro Okada

Katsumi Ishikawa

Yoshii Morishita

Takeyuki Itabashi

Masanobu Hanazono

Mitsuo Katayose

Shun-ichi Narumi

Miki Hara

Shigeaki Funyu

Hisashi Takano

Yuji Enomoto

Shinji Narishige

Tetsuo Ito

Atsushi Kato

Katsuhiro Komuro

Takayuki Kanda

Kiyonori Shiraki

Tadashi Imanaka

Yusuke Asari

Shiroyasu Odai

Hisamitsu Hatou

Ryoso Masaki

Akira Sugawara

Atsushi Nakamura

Hiroyuki Hoshiya

Takanori Yamazaki

Noriaki Hino

Haruo Koharagi

Noboru Shimizu

Masahiro Mita

Katsumi Hoshino

Motoya Ito

Takashi Kawabe

Kunihiro Maeda

Naofumi Chiwata

Shohei Terada

Masaaki Sano

Hirotsugu Fukuoka

Takeshi Yasuda

Katsuya Mitsuoka

Seunghwan Park

Masahiro Masuzawa

Masafumi Noujima

Kazuya Shinagawa

Isao Kitagawa

Naoya Okizaki

Koichiro Ohara

Kotaro Shiino

Shinya Tamura

Koji Numakura

Noboru Yoshida

Masato Miyataki

Tetsuro Kuroda

Nobuo Abe

Shintaro Tsujimi

Tomohiro Tabata

The present invention provides a soft magnetic iron sheet exhibiting a high saturation magnetic flux density and a low iron loss as compared with an electromagnetic pure iron sheet, a method for producing the soft magnetic iron sheet, and, an iron core and a dynamo-electric machine, each using the soft magnetic iron sheet. The soft magnetic iron sheet according to the present invention includes: iron as a main component; and nitrogen, in which the soft magnetic iron sheet includes, along a thickness direction of the soft magnetic iron sheet: a high nitrogen concentration layer having a nitrogen concentration of 2 at. % to 11 at. %; a low nitrogen concentration layer having a nitrogen concentration of half or less of the nitrogen concentration of the high nitrogen concentration layer; and a nitrogen concentration transition layer connecting the nitrogen concentration of the high nitrogen concentration layer and the nitrogen concentration of the low nitrogen concentration layer, and wherein a surface layer region including at least both main surfaces of the soft magnetic iron sheet is the low nitrogen concentration layer.

Soft magnetic iron sheet, method for producing soft magnetic iron sheet, and, iron core and dynamo-electric machine, each using soft magnetic iron sheet

The present invention aims at providing an iron-nitrogen-based soft magnetic steel sheet having a saturation magnetic flux density higher than that of pure iron, a method for manufacturing the soft magnetic steel sheet, and a core and a dynamo-electric machine in which the soft magnetic steel sheet is used. The soft magnetic steel sheet according to the present invention includes C, N, and the balance of Fe and inevitable impurities and is comprised of an α phase, an α' phase, an α″ phase, and a γ phase. The α phase serves as a main phase, a volume ratio of the α″ phase is 10% or more, and a volume ratio of the γ phase is 5% or less. The core according to the present invention includes a laminated body of the soft magnetic steel sheets.

Soft magnetic steel sheet, method for manufacturing the soft magnetic steel sheet, and core and dynamo-electric machine in which the soft magnetic steel sheet is used

Provided are: a sintered magnet having an improved maximum energy product while maintaining the magnetic coercivity of the magnet; and a production method for such a sintered magnet. The sintered magnet () according to the present invention comprises particles () each including: a main phase () in which the main component is a compound containing a rare-earth element and iron; and a diffusion layer () provided on the surface of the main phase (). The diffusion layers () are characterized by: containing, as a main component, a compound resulting from a solid-solution of carbon and/or nitrogen in said compound of the main phase (); and having a concentration gradient of carbon and/or nitrogen from the surfaces of the particles () toward the interior thereof.

Sintered magnet and production method for sintered magnet

A soft magnetic material that is sheet-shaped or foil-shaped and has a high saturation magnetic flux density, contains iron, carbon, and nitrogen, and includes a martensite containing carbon and nitrogen, and γ-Fe, wherein the γ-Fe includes a nitrogen-containing phase. The soft magnetic material is produced by steps of heating an iron-based material that is sheet-shaped or foil-shaped, carburizing the iron-based material with a carburizing gas, dispersing a granular carbide in α-Fe in the iron-based material at a temperature equal to or lower than a eutectoid temperature, transforming the α-Fe into γ-Fe at a temperature higher than the eutectoid temperature, diffusing nitrogen into the γ-Fe using a nitrogen supply gas to form γ-Fe—N—C, and rapidly heating and then rapidly cooling the γ-Fe—N—C to transform the γ-Fe—N—C into a martensite. The result is a thermally stable soft magnetic material having a saturation magnetic flux density higher than that of pure iron.

Soft magnetic material and method for producing the same, and electric motor containing soft magnetic material

An object of the present invention is to provide a ball screw having a structure in which a screw shaft and a nut satisfy required performance and having improved durability, a method for manufacturing the ball screw, a power steering device, and a method for manufacturing the power steering device. A ball screw according to the present invention includes: a nut made of a steel substrate having an inner peripheral surface on which a female screw is formed; a screw shaft that is combined with the nut and is made of a steel substrate having an outer peripheral surface on which a male screw facing the female screw is formed; and a plurality of balls arranged between the female screw and the male screw. A surface of the nut in contact with the ball and a surface of the screw shaft in contact with the ball each have carburized layers. A carbon concentration in the carburized layer of the nut is higher than a carbon concentration in the carburized layer of the screw shaft.

Ball screw, method for manufacturing ball screw, power steering device, and method for manufacturing power steering device

Disclosed herein is a technique to reduce the residual stress of a steel material while improving the mechanical property and the corrosion resistance of the material. A steel material is provided that includes a plurality of ferrite crystal grains, and a laminar iron-rich phase formed at unidirectionally occurring grain boundaries of all grain boundaries of the ferrite crystal grains. A material processing method is provided that includes: heating a steel material that contains a plurality of ferrite crystal grains; applying a magnetic field to a heated portion while heating the steel material; applying an electric field to the heated portion in a direction that crosses the direction of the applied magnetic field while heating the steel material; and measuring a displacement occurring in the steel material under the magnetic field and the electric field.

Steel material, material processing method, and material processing apparatus

The purpose of the present invention is to provide an alcoholic solvent, in which FeCo-based particles becoming a soft magnet are improved, for enhancing properties of a magnetic material using no heavy rare earth elements, and is to provide a sintered magnet produced by using it.

Alcoholic solution and sintered magnet

Disclosed is a sintered magnet which is a rare-earth magnet using a less amount of a rare-earth element but having a higher maximum energy product and a higher coercivity. The sintered magnet includes a NdFeB crystal; and an FeCo crystal adjacent to the NdFeB crystal through the medium of a grain boundary. The FeCo crystal includes a core and a periphery and has a cobalt concentration decreasing from the core to the periphery. The FeCo crystal has a difference in cobalt concentration of 2 atomic percent or more between the core and the periphery. In the NdFeB crystal, cobalt and a heavy rare-earth element are unevenly distributed and enriched in the vicinity of the grain boundary.

Sintered magnet

Characteristics of a magnetic material are improved without using a heavy rare earth element as a scarce resource. By incorporating fluorine into a magnetic powder and controlling the crystal orientation in crystal grains, a magnetic material securing magnetic characteristics such as coercive force and residual flux density can be fabricated. As a result, the resource problem with heavy rare earth elements can be solved, and the magnetic material can be applied to magnetic circuits that require a high energy product, including various rotating machines and voice coil motors of hard discs.

Magnetic material and motor using the same

A ferromagnetic compound magnet in accordance with the present invention includes a ferromagnetic compound based on a binary alloy containing R&#x2014;Fe system (R is a 4f transition element or Y) or a ternary allay containing R&#x2014;Fe-T system (R is a 4f transition element or Y, and T is a 3d transition element except for Fe, or Mo, Nb or W), the ferromagnetic compound being characterized by: atomic percentage of the element R to the element Fe or to the elements Fe and T is 15% or lower; an element F is incorporated into an interstitial position in a crystal lattice of the alloy. The ferromagnetic compound is expressed in a chemical formula of: RFeF; R(Fe,T)F; RFeF; R(Fe,T)F; RFeF; or R(Fe,T)F(0&#x3c;x&#x2266;3, 0&#x3c;y&#x2266;4, 0&#x3c;z&#x2266;1).

Ferromagnetic compound magnet

To mold a high-resistance magnet at low temperature, including room temperature, the magnet includes magnetic powders, metallic powders having a lower hardness than the magnetic powders and a high-resistance layer, wherein the magnetic powders occupy a larger volume than the metallic powders. In particular, the high-resistance layer contains a fluorine compound and is placed between the magnetic powder and the metallic powders.

Powdered-iron magnet and rotating machine using the same

A permanent magnet type electric rotating machine having a high resistance permanent magnet used for the electric rotating machine, the permanent magnet containing a magnetic powder and a fluorine compound, in which the current waveform is controlled for reducing the loss to satisfy a relation: A&#x3c;C&#x3c;B and restrict the 7th higher-harmonic component to 20% or less where A is the content for the 5th higher harmonic component, B is the content for the 7th higher harmonic component, and C is the content for the 11th higher harmonic component, assuming the total of contents for the fundamental components of a current supplied to the findings being 100%.

Permanent magnet type electric rotating machine

An R&#x2014;Fe&#x2014;B sintered magnet has a structure including main phase crystal grains and a grain boundary area surrounding the crystal grains. The sintered magnet includes fluorine and a specified metal element selected from elements belonging to Group 2 through Group 16 of periodic table excepting the rare earth element, carbon and boron. The fluorine has a higher concentration in a region closer to a magnet surface than in the center. The specified element also has a higher concentration in the region closer to the surface. The sintered magnet includes oxyfluoride containing carbon, Dy and the metal element in a grain boundary area region at a distance of 1 &#x3bc;m or greater from the magnet surface, and the carbon has a higher concentration than the concentration of the metal element in a region at a distance of 1 &#x3bc;m to 500 &#x3bc;m from the magnet surface.

Rotating machine with sintered magnet and method for producing sintered magnet

A rare earth magnet having a composition represented by RTB wherein R denotes a rare earth element, T a transition metal and B boron, the magnet being composed of magnet powder constituted by crystalline particles. The particles of the magnetic powder have a ratio of a short diameter being 10 &#x3bc;m or more to a long diameter is 0.5 or less. An element Rm having a magnetic anisotropy higher than that of the rare earth element is contained in the surface and inside of the magnet constituted by the magnet powder in an approximately constant concentration. An oxy-fluoride and carbon are present at boundaries of the particles of the magnet powder.

Rare earth magnet

A manufacturing method of a magnetic core includes a first step of applying a treatment liquid for forming an insulating film to iron powder; a second step of heat-treating the iron powder to which the treatment liquid has been applied, at a temperature higher than 350 degrees; a third step of compacting the heat-treated iron powder to form a magnetic core; and a forth step of heat-treating the magnetic core at a temperature ranging from 600 degrees to 800 degrees.

Compacted magnetic core, production method of the same, and motor for electric vehicle

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Hitachi, Japan

Matahiro Komuro