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http://dx.doi.org/10.18770/KEPCO.2020.06.01.041

Investigation of the Contributions of Creep and Thermal Fatigue to Failure of a High-Intermediate Pressure Steam Turbine Casing  

Lee, Jaehong (KEPCO Research Institute, Korea Electric Power Corporation)
Jung, Nam-gun (KEPCO Research Institute, Korea Electric Power Corporation)
Publication Information
KEPCO Journal on Electric Power and Energy / v.6, no.1, 2020 , pp. 41-47 More about this Journal
Abstract
The contribution of damage mechanisms to failure of steam turbine casing made of Cr-Mo-V steel was investigated. Creep-fatigue interaction on the HP side corner of turbine casing was revealed as the root cause of the catastrophic failure performed by metallurgical analysis. The steady-state pressure and transient thermal stress were analyzed based on the actual operating condition of the thermal plant. Damage of creep-fatigue interaction to crack initiation was evaluated with multiaxial effects. The contribution ratio of creep and fatigue to the crack initiation was estimated to 3:1. Temporary geometrical correct action with repair weld was executed. For long-term operation, design improvement of casing equipment for creep resistance should be needed.
Keywords
Creep-Fatigue Interaction; Metallurgical Examination; Damage Assessment; High and Intermediate Pressure Steam Turbine Casing;
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