A NEW APPROACH TO THE EVALUATION OF MAGNETIC PARAMETERS FOR NON-DESTRUCTIVE INSPECTION OF STEEL DEGRADATION

Elemír Ušák

   Various conventional magnetic parameters, such as the coercivity, remanence, hysteresis loop area, initial permeability, etc as well as non-standard parameters evaluated by means of Magnetic Adaptive Testing (eg relative differential permeability) are strongly affected by the microstructure of tested materials. Thus, the relationship between these parameters and microstructural changes due to thermal and/or mechanical treatment or even long-term neutron irradiation can be used as a good tool for nondestructive inspection of these changes, possibly associated with material fatigue. In this work, a new approach to the evaluation of magnetic parameters as well as some preliminary results obtained on the samples exposed to artificial ageing are to be presented.

Keywords: non-destructive evaluation, microstructural changes, artificial ageing, Magnetic Adaptive Testing (MAT)

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