Abstract
Changes in electrochemical properties of directionally solidified Ni-base superalloy CM 247 LC due to creep have been investigated. The electrochemical polarization technique has been applied to creep-ruptured and creep-interrupted specimens under various creep condition in order to examine a detectability of creep damage. Experimental results on electrochemical polarization measurements revealed that the peak current density "Ip" and "Ipr" which appeared at a specific potential during potentiodynamic polarization reactivation measurements in dilute glyceregia solution increased with increased thermal history and showed a good correlation with Larson-Miller Parameter value, Ip and Ipr value reflected both a thermal aging effect and a stress effect, and increased with a creep life fraction. The increases in Ip and Ipr were mainly corresponded to increases in preferential dissolution rate of γ phase at γ/γ interface. This preferential dissolution was considered as a result from degradation of corrosion resistance of γ phase at γ/γ interface which may be attributable to creep damage accumulation. As a consequence, the creep damage in CM 247 LC can be quantitatively evaluated by the electrochemical technique.
Original language | English |
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Pages (from-to) | 1997-2001 |
Number of pages | 5 |
Journal | Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A |
Volume | 64 |
Issue number | 623 |
DOIs | |
Publication status | Published - 1998 |
Keywords
- Creep
- Creep damage evaluation
- Directionally solidified Ni-base superalloy
- Electrochemical property
- Electrochemistry
- Nondestructive inspection
- γ-Channel
- γ/γ Interface
- γPhase
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering