Mitsubishi Heavy Industries Limited

Takeo Tokumoto

Yuichi Hirakawa

Takeki Nakayama

Yasuyuki Tatsumi

Hiroaki Fukushima

Hiroaki Yoshida

Hiromu Sagimori

Masahiko Yamashita

A method for evaluating a crack in a metal member comprises a first removal step (S) and a second removal step (S). In the first removal step (S), a step for electrolyzing a metal member having an oxide scale formed on a surface thereof, a step for acquiring an image of the oxide scale as a first image, and a step for determining whether or not a scale crack has occurred are repeated until occurrence of a scale crack is determined. In the second removal step (S), a step for electrolyzing the metal member having the scale crack, a second image acquisition step for acquiring an image of the oxide scale as a second image, and a second determination step for determining whether or not the scale crack has disappeared are repeated until disappearance of the oxide scale is determined.

Method for evaluating crack in metal member and method for evaluating fatigue damage in metal member

A flow guide is provided with a flange, a guide plate, and an inside member. A ring groove which is recessed to the radially outer side from an inner circumferential surface and which extends in a circumferential direction based on the axis is formed in the flange. The inside member includes a fitted portion which enters the ring groove, and a cover portion which faces the inner circumferential surface of the flange in the radial direction. The cover portion covers at least parts of the inner circumferential surface of the flange and an inner circumferential surface of the guide plate that face a tip end of a moving blade in the radial direction. The cover portion is formed from a material having a higher erosion resistance with respect to steam and steam drain than the flange.

Flow guide, steam turbine, inside member, and method for manufacturing flow guide

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Yokohama, Japan

Takeo Tokumoto