Prediction of remnant magnetization change during a demagnetization process

Demagnetization of a ferromagnetic tube was performed by applying an alternating magnetic field with a constant decrement. As a way of predicting the remnant magnetization of the tube with every magnetic field applied, an analytical expression was suggested. Three analytical expressions were obtained from the demagnetization curve and corresponded to the saturation region, the hysteresis region and the initial region. The demagnetization curve was obtained through a demagnetization process when the magnitude of the first magnetic field was 2000 A/m. The analytical expressions could be applied to experimental results when the magnitudes of the first magnetic field were 200 A/m, 1600 A/m, and 1200 A/m, respectively.