To improve the whole manufacturing ability and to reduce the manufacturing cost by weld-joining after separatly manufacturing a disk part and blade parts.
The manufacturing processes are composed of the following processes. (1) A disk 1 is forged to a desired shape. (2) The forged disk 1 is machined and set to the shape and the size in each part. (3) Plural blades 2, 3 are formed with a precision forging. (4) The blades 2, 3 are assembled with the disk 1 to set the position of each' blade. (5) Joining positions between the blades 2, 3 and the disk 1 are welded (Angles α of welding bivels W are equalized to all bevels W). (6) Metallurgical structure is martenstized with a heat treatment. (7) A precise finishing is executed to each part. The above processes are executed in order and thereby, the influence, by which an impellar forms three dimensional shape in the blade parts, is the hardly received, and the correspondence to the large scale is facilitated. Further, the reduction of the manufacturing cost and the improvement of precision of the impellar can be obtd.
OYAMA MITSUO
KAWASHIMA IWAO
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