Hitachi, Ltd.

Tetsuo Okuni

Takeshi Wada

Hisanao Kita

Yoshio Namatame, Deceased

Masao Ishihara

A method of fabricating a structural member such as a wicket gate for water turbines by electro slag forming comprises the steps of mounting a water-cooled metal mold on a part of a previously formed structural member, such as a stem; melting electrodes inserted in the water-cooled metal mold to form the other part of the structural member such as a vane portion of the wicket gate on the previously formed structural member. The previously formed structural member has a concave portion which is exposed in the water-cooled metal mold and the water-cooled metal mold is mounted so as to contact with the previously formed structural member at the lower portion than the top of the concave portion. The previously formed structural member is melted gradually from the central portion of the concave to the outer periphery and then such a portion as the vane portion is formed by molten metal of the electrode.

Method of fabricating a structural member by electro slag forming

A method of manufacturing a stay ring for a water turbine or pump turbine having an upper annular disc, a lower annular disc and a plurality of circumferentially equal-distantly spaced stay vanes extending between the upper and lower annular discs. The method includes forming openings in the upper and lower annular discs at locations where the stay vanes are to be positioned, locating the upper and the lower annular discs such that the openings in the upper and lower annular discs are put in vertical alignment, placing a plurality of molds each having therein a space of a shape conforming to that of the stay vane, such that the spaces in the molds are brought into communication with respective pairs of openings of the upper and the lower discs, and effecting an electroslag welding in the space in each mold through respective openings of the upper annular disc to fill the space with the welding metal, thereby to form the stay vanes and, at the same time, to connect the upper and lower annular discs through thus formed stay vanes.

Method of manufacturing stay ring for water turbine and pump turbine

A nozzle structure of electroslag welding machines for use in welding planks having heavier thicknesses compared to previously electroslag welded planks, and having as much as 800 mm thicknesses, in which the nozzle structure is formed of a plurality of bent pipes rigidly connected with each other to form a fan-shaped nozzle structure. A plurality of wires are continuously fed through each of the bent pipes into a weld gap formed by faces of planks to be welded.

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Hitachi, Japan

Tetsuo Okuni