Proceedings of the KSME Conference (대한기계학회:학술대회논문집)
- 2004.04a
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- Pages.336-341
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- 2004
Nondestructive Evaluation for Thermally Degraded Co-base Superalloy by Scanning Acoustic Microscope
초음파현미경을 이용한 Co 기 초내열 합금 열화재의 비파괴평가
- Published : 2004.04.28
Abstract
This research investigates the feasibility of ultrasonic microscope for nondestructive assessment of thermal degradation in artificially aged commercial Co-base superalloy, FSX414. This alloy has been used for high temperature structure applications such as stationary gas turbine blade and nozzle chamber in fossil plant. Microstructural change was found that the fine carbides became coarser and spheroidized in matrix as aging time increased. The leaky surface acoustic wave velocity gradually decreases by a maximum of 4.7% with increasing aging time up to 4,000hours. However, the longitudinal wave velocity has a little change. Also, it has a good correlation between leaky surface acoustic wave velocity and Vickers hardness. Consequently, LSAW can be used to examine the degree of degradation in thermally aged Co-base superalloy.
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