| abstract |
The present invention is a method of manufacturing a ring-shaped formed body, the manufacturing method comprising: a forging step of forging an alloy piece to obtain a disc-shaped forged body; and a ring rolling step of manufacturing a forged body by forming a through hole in the forged body The ring-shaped intermediate body is subjected to ring rolling to obtain a ring-shaped formed body, and the method is characterized in that the forging step includes at least two hot forging steps. In hot forging, the strain rate is at most 0.5s -1 , the absolute value of the strain in the circumferential direction of the forged body εθ1 is at least 0.3, the absolute value of the strain in the height direction of the forged body εh is at least 0.3, and the absolute value of the strain is between The ratio εh/εθ1 is in the range of 0.4 to 2.5. |