Hitachi, Ltd.

Hitachi-Ge Nuclear Energy, Ltd.

Okano Valve Mfg. Co. Ltd.

Yoshihisa Kiyotoki

Jiro Kuniya

Mitsuo Chigasaki

Yoshiteru Chiba

Shizuo Matsushita

Takahiko Kato

Hirotsugu Kawanaka

Sei Hirano

Daisuke Hirasawa

Kenji Onodera

Keisuke Sakemura

Hiroyuki Ohta

Kenji Araki

Akira Sakamoto

Hiromi Shimazu

Junya Kaneda

Seunghwan Park

Yohei Tanno

Hiroshi Shiratori

Kikuo Takeshima

Yusaku Maruno

Yukari Nakayama

Shinji Matsushita

Hajime Miyata

Shin Kumagai

Ryo Kubota

Yukio Imoto

Yoshitomo Kanemura

Takayoshi Nakashima

Yoshiharu Kawahara

Yuta Fukuda

Keiji Sasaki

Hisashi Satou

Intended is to improve the corrosion resistance of an overlay used in a nuclear power plant, and to reduce dissolution of cobalt from an overlay. The corrosion and wear resistant overlayis formed along a surface of a baseby laser lamination modeling, and is configured from a plurality of metal layers, andof a Co-base alloy. The thickness of carbide eutectics that precipitate in the metal layers, andis the largest in the metal layerclosest to the base, and is gradually smaller in the metal layers, andfarther away from the base. The intensity of the laser beam applied to form layers by laser lamination modeling is adjusted so that the carbide eutectics that precipitate in at least the outermost metal layerhave a controlled size of 10 μm or less.

Corrosion and wear resistant overlay, method for forming corrosion and wear resistant overlay, and corrosion and wear resistant valve

To provide a fluid contact member whose corrosion resistance is particularly further improved than that in the related art. In order to solve this problem, a fluid contact memberincludes a fluid contact portionconfigured to be in contact with a fluid, the fluid contact portionhas a cobalt-based alloy phasehaving a dendrite, and a compound phaseformed in an arm space of the dendrite and containing chromium carbide, and among a plurality of secondary armsextending from one primary armconstituting the dendrite, an average interval between adjacent secondary armsis 5 μm or less. At this time, the average interval is preferably 3 μm or less. Further, the compound phaseis preferably formed discontinuously in the dendrite arm space.

Fluid contact member and method of manufacturing fluid contact member

The invention provides a method of manufacturing a transition piece that has a high degree of freedom in adjustment of a length, a shape, or the like, can carry out a dissimilar metal welding easily, and is easy to perform, and a transition piece. The transition piece includes one end having the same composition as one material to be welded, another end having the same composition as another material to be welded, and an intermediate layer formed between the one end and the other end. The composition of the one end and the composition of the other end become the same as approaching a center. In the method of manufacturing the transition piece according to the invention, at least the intermediate layer among the one end, the other end, and the intermediate layer is formed by a additive manufacturing method.

Method of manufacturing transition piece and transition piece

A high reliable water injection device is provided that injects water into a reactor containment vessel and can reliably shut off cooling water at normal times and quickly and reliably inject water into the reactor containment vessel without the need for external power, in a case of emergency. The water injection device injects water into a reactor containment vessel includes a flow path through which cooling water is supplied; a disk that closes the flow path; a swing arm that is connected to the disk and performs closing and opening of the flow path by the disk; and a weight that is connected to the swing arm via a swing lever, in which the weight is supported by a support member made of a low melting point alloy.

Water injection device

A butterfly valve includes a valve body-side valve seat section, a valve box-side valve seat section, and a valve movement mechanism. The valve movement mechanism includes a cam groove, a cam projection, and a reverse key. The valve movement mechanism moves the valve body in an extending direction of the flow passage along with rotation of the valve shaft between a blocking position and an open position. One of the valve body-side valve seat section and the valve box-side valve seat section is formed of a laminated material composed of alternatingly stacked plates made of metal and plates made of expanded graphite.

Butterfly valve formed of a laminated material

A gas supply apparatus of the present invention includes a gas discharge line of a first electromagnetic valve having s a switching valve placed therein, and a second electromagnetic valve placed between the switching valve and a gas supply source. The switching valve switches between a gas discharge from the first electromagnetic valve and a gas supply to the first electromagnetic valve. At the time of a normal operation, the second electromagnetic valve opens a gas discharge line side and closes a switching valve side, and when the power source is lost, the second electromagnetic valve opens the switching valve side and closes the gas discharge line side. In this way, even when the power source is lost, an operating valve can not only be operated remotely but also be operated safely by a remote operator.

Gas supply apparatus and air or nitrogen supply apparatus of nuclear plant

The invention provides a valve which suppresses a continuous corrosion of a chemical compound phase such as an eutectic carbide or the like in a valve seat, and improves a corrosion resistance, an impact resistance and an erosion resistance of the valve seat. The invention disperses a chemical compound phase such as the eutectic carbide or the like crystallizing in a dendrite gap as a granular shape or a blocky shape which is equal to or less than about 100 &#x3bc;m, by moving a tool rotating in a crimped state by a load application to a vertical direction to a surface of the valve seat so as to carry out a friction stir processing, and forming a weld metallographic structure of a surface layer portion of the valve seat as a cubic.

Valves having high wear-resistance and high corrosion-resistance

A monitoring system for valve device according to the present invention comprises a semiconductor single crystalline substrate including a bridged circuit and the bridged circuit comprising impurity-diffused resistors. The semiconductor single crystalline substrate is mounted to any of a valve device's valve stem, valve yoke, drive shaft, or elastic body disposed at the end of the drive shaft. Thrust and torque of the valve device are measured by the semiconductor single crystalline substrate and then the measured values are used for monitoring the valve device.

Monitoring system for valve device

A valve which is cobalt-free excellent in wear resistance and seizure resistance manufactured by forming valve seats for a valve disc and a valve body with a nickel base alloy in which silicide particles or boride particles of small particle size are finely dispersed, and the valve seat is bonded to the valve disc or the valve body by way of an insert material comprising a nickel base alloy of a lower melting point by transient liquid phase diffusion bonding.

Valve and manufacturing method thereof

In the joint construction of cobalt-based alloy, a cobalt-based alloy layer, in which granular or massive eutectic carbidedisperses, is joined to a metal of a base metalvia an insert metal layer. For the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100&#xb0; C. for a retention time of 1 hour with an insert metal with a thickness of about 40 &#x3bc;m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 &#x3bc;m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layerafter bonding contains granular or massive eutectic carbide.

Joint construction of cobalt-based alloy

In the joint construction of cobalt-based alloy, a cobalt-based alloy layerin which granular or massive eutectic carbidedisperses, is joined to a metal of a base metalvia an insert metal layerFor the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100&#xb0; C. for a retention time of 1 hour with an insert metal with a thickness of about 40 &#x3bc;m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 &#x3bc;m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layerafter bonding contains granular or massive eutectic carbide.

A valve is characterized by excellent corrosion and wear resistance and maintainability due to use of a bonding corrosion and wear proof alloy containing non-continuously distributed eutectic carbide on the sliding portions of various types of apparatuses and valves by diffusion bonding. This serves to improve the maintainability of a thermal and nuclear power plant and to provide a nuclear power plant using recirculating water, which ensures excellent working safety, in particular. The corrosion and wear proof alloy is characterized in that network-formed eutectic carbide in the alloy containing the cast structure base metal and eutectic carbide is formed into(multiple) granules or lumps having a particle size of 30 microns or less so that said eutectic carbide is non-continuously distributed.

Valve bonded with corrosion and wear proof alloy and apparatuses using said valve

A float type liquid level meter is provided having an enhanced resistance against vibration transmitted from outside of the float type liquid level meter. The inventor obtained a finding that an external vibration is amplified with a connecting lever which is composing a part of the float type liquid level meter and a fluctuation of an output signal of the float type liquid level meter is proportional to the vibration of the connecting lever. An enhanced resistance against vibration is achieved by providing a connecting lever having a structure which prevents the connecting lever from generating vibration of a low order mode.

Growing community of inventors

Hitachinaka, Japan

Yoshihisa Kiyotoki