Hitachi-ge Nuclear Energy, Ltd.

Sei Hirano

Yoshihisa Kiyotoki

Hirotsugu Kawanaka

Junya Kaneda

Hiroshi Shiratori

Daisuke Hirasawa

Hajime Miyata

Yukari Nakayama

Shinji Matsushita

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

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Hitachi, Japan

Sei Hirano