Quantification of Barkhausen Noise Method by Microstructural Analysis and Nondestructive Evaluation of Fracture Toughness

摘要

In this study, we performed experiments on the coercive force and the Barkhausen noise(BN) for the various microstructure of ultra-fine grained steels and SA508 cl.3 steels according to the pre-processing condition. We tried to quantify the BN from the relationship between the velocity of magnetic domain walls and the retarding force replaced with the coercive force in the domain wall movement. In order to quantify the BN, we observed the variation of microstructure of ultra-fine grained steels and SA508 cl.3 steels and analyzed the relationship between the microstructural variation and BN. We then compared the results by the standardized fracture toughness test with the fracture toughness by the quantified Barkhausen noise from the two intermediary parameters. These two parameters are considered as the grain size and the distribution of non-magnetic particles on each specimen having the different BN. From these results, we can testify the quantification of the BN and the possibility of nondestructive fracture toughness test by BN method.