外部磁場による縦波振幅変化の周波数依存性と非破壊残留応力測定への適用
1994 年 60 巻 573 号 p. 1280-1287
詳細
1994 年 60 巻 573 号 p. 1280-1287
Frequency dependence of magnetically induced amplitude change (MIAC) of longitudinal wave is experimentally investigated for JIS-SS41 low-carbon steel. The amplitude of an elastic wave that propagates in a ferromagnetic material is smaller in the demagnetized state than that in the magnetically saturated state, which is the pure elastic state. This occurs because of the existence of magnetoelastic interaction and microscopic eddy current. When an external magnetic field is applied, the amplitude increases accordingly. Since stress causes reorientation of magnetic domains, the MIAC depends on the stress. In this study, effects of stress and frequency on the MIAC are investigated. It is found that the MIAC depends on the stress and that the frequency dependence of the MIAC is affected by the sign of the stress. The results are applied to nondestructive evaluation of the residual stress in a butt-welded specimen.
