NDTnet 1998 Aug, Vol.3 No.8

Abstract

For the decision of many problems, connected with remagnetization of ferromagnetic bodies it is very important to have analytical expression, which would describe the process. In nondestructive testing of the ferromagnetic articles the methods, based on research of processes of remagnetization and measurement of their magnetic characteristics, such, as H_c - coercive force and magnetization J_d [1], are often used. It is possible if there is a correlation dependence between residual magnetization and parameter under testing (for example, quality of heat treatment). For development of such methods of the testing, and also for calculation of magnetic circuits with nonlinear elements it is desirable to have analytical expression for the description of processes of remagnetization of ferromagnetic body. In [2] the analytical expression for the description of a symmetric hysteresis loop of ferromagnetic material is submitted. However in practice it is necessary to take into account process of remagnetization of ferromagnetic body. It results in taking into account of demagnetization factor of real bodies. Expressions for the description both ascending, and descending branches of histeresis loop were absent. We have received these expressions, connecting the process of remagnetization of a body with magnetic parameters of a material of a body (J_r - residual magnetization, J_s -maximum magnetization. H_c - coercive force), and its demagnetization factor N [3]:


- is an externalmagnetic field, the up sign before H_c corresponds to a descending branch of a loop of a hysteresis, down - ascending.The received expressions can be used for development of new methods of nondestructive testing of the articles, and for calculation of magnetization of bodies, being under effect of fields of external sources.

References
1. Sandomirskii. S. G. Defektoskopya. 1996 No. 7 p. 25-45.
2. Zatsepin N. N.Gorbash. V. G. Materials Evalutionvol.47/91989 p. 1074-1077.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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