摘要 |
In manufacturing a multi-finger pinned root pin-coupling a turbine blade made of a high-strength material and a rotor disc, a reamer used to ream a pin insertion hole formed through a turbine blade attachment base is removed from the pin insertion hole while being rotated so as to cause a scratch formed by a chip on the inner surface of the pin insertion hole to be inclined with respect to the axial direction of the pin insertion hole. This brings the direction of the scratch on the inner surface of the pin insertion hole and the direction of tensile stress generated on the inner surface of the pin insertion hole adequately close to be parallel to each other. As a result, the fatigue strength reduction caused by the scratch can be inhibited.
|