低圧タービンロータ翼溝部の腐食疲労き裂伝ぱ余寿命評価

概要

論文の詳細を見る
The objective of this study is to develop a method for evaluating corrosion fatigue crack propagation behavior at Christmas-tree-type low pressure (LP) steam turbine rotor groove. The rotor groove examined in this study has three hooks. Centrifugal force of the blade is supported through these hooks. Each corner of the hook can be a candidate for crack initiation site, therefore, the condition where cracks initiate and propagate simultaneously at several grooves must be considered. A procedure is presented to assess the crack propagation behavior under such a condition. It is shown that the crack propagation behavior is strongly affected by gap size between the rotor groove and the inserted blade root. The gap is introduced unavoidably within a manufacturing tolerance. Finally a simple method is proposed for evaluating residual life of the rotor groove after crack initiation is proposed.
社団法人日本機械学会の論文
2003-02-25