• Journal of The Institute of Information and Telecommunication Facilities Engineering
• /
• v.11 no.2
• /
• pp.46-51
• /
• 2012

In this paper deperm performance on deperm protocol cycle has been analyzed. As deperm protocol increases cycle, deperm performance improves and duration time will increase. Thus, it's essential that proper deperm cycle that is fit on vessel should be applied. To compare deperm performance according to cycle changes, small deperm system has been made and small vessel had been made with SM45C materials. As Anhysteretic deperm protocol applied, the result on the increase of deperm performance according to the increase of cycle has been gotten.

• Journal of the Korean Magnetics Society
• /
• v.23 no.2
• /
• pp.54-61
• /
• 2013

Ferromagnetic material's residual magnetization is remained because of the interaction between domains from external apply field, so the electrical and electronic industry and area of defense development request deperm protocol which makes the residual magnetization to 0. But the deperm protocols which are used theses days are developed by using only experience and experiment, so we have to develop deperm protocol considering hysteresis curve. In this paper, Anhysteretic Deperm, Deperm-ME, Flash-Deperm were analyzed using two dimensional finite element method and Preisach model that was formulated by property of magnetic materials. From that analysis, the relations between hysteresis curve and deperm variable are compared by analyzing the trace of Preisach plane. Also, an efficient current ratio of deperm protocol, is proposed.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.14 no.3
• /
• pp.359-363
• /
• 2011

An orthogonal magnetic field is often used for a military vessel in the deperm process such as Flash D deperm protocol and Anhysteretic deperm protocol. The effect of the orthogonal magnetic field on a deperm performance was investigated for a sample with strain-induced magnetization and field-induced magnetization given to different direction. A 70mm wide, 110mm long and 0.25mm thick rectangular steel plate was bent to have U-shape and to generate a strong strain on the bottom region of U-shaped steel plate. Field-induced magnetization was attached by NdFeB permanent magnet. Demagnetization was performed by applying magnetic field with a step decrement from the first field(the first shot) under the action of DC bias field.

• Journal of Magnetics
• /
• v.19 no.1
• /
• pp.43-48
• /
• 2014

Magnetic materials with large coercive force and high squareness ratio are currently developing to meet an industrial demand. Since a ferromagnetic material has hysteresis characteristics, it is hard to demagnetize a ferromagnetic material precisely. In this paper, we describe deperm processes and conduct an analysis of residual magnetization of ferromagnetic material using the Preisach modeling with a two-dimensional finite elements method (FEM). From the results, it was shown that an exponential decrement form of deperm protocol is more efficient than a linear decrement form because of the demagnetizing field in the ferromagnetic material.