MAGNETOACOUSTIC MEASUREMENTS ON STEEL SAMPLES AT LOW MAGNETIZING FREQUENCIES

Oleksiy Perevertov – Alexandr Stupakov

   The magneto-acoustic emission (MAE) is measured at low frequencies, sample being magnetized by an external yoke. The sample surface field was accurately measured. Influence of the field and flux density rates on the resulting MAE envelope was studied. It was found that two-peaks MAE with a minimum around the coercivity was due to the minimum in the field rate dH/dt. Division of the MAE signal by the field rate completely removed that artificial minimum making one-peak shape resem-bling the differential permeability curve. This work demonstrated importance of the field rate control for MAE measurements to make them reliable and repeatable.

Keywords: magneto-acoustic emission, surface magnetic field, steel, magnetic hysteresis

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