著者

大谷 俊博

出版者

湘南工科大学

雑誌

湘南工科大学紀要 (ISSN:09192549)

巻号頁・発行日

vol.42, no.1, pp.1-10, 2008-03-18

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The microstructural evolution of the Cr-Mo-V ferritic steel, JIS-SNB16, subjected to a tensile creep test at 923 K wasstudied by monitoring the shear wave attenuation and velocity with electromagnetic acoustic resonance (EMAR). Thisstudy revealed an attenuation peak independent of the applied stress and the type of EMAT (electromagnetic acoustictransducer) used at around 30% of the creep life and a minimum value at 50%. This novel phenomenon is interpreted asresulting from microstructural changes, including strain hardening and dislocation recovery. This interpretation is supportedby TEM observations of dislocation structure. The relationship between attenuation change and microstructureevolution can be explained with the string model for dislocation vibration. EMAR is shown to possess the potential toassess the progress of creep damage and predict the remaining creep life of various metals.