The influence of modeled B– H curve on the density of the magnetic leakage flux due to a flaw using yoke-magnetization

Abstract

Factors which influence magnetic leakage flux density due to a flaw in magnetic leakage flux testing are the shape and dimensions of the flaw, the B– H curves, the magnetizing conditions, lift-off, etc. The influence of B– H curves which were approximated by two lines was already reported and it was documented that both initial permeability and the magnetic flux density in the saturation state are the influence parameters. In the study we discuss here, we will document that the phenomenon of magnetic saturation—observed near the bottom of the flaw—is an essential effect when we concentrate on the influences of two parameters, i.e. the average magnetic flux density in a specimen and the intensity of magnetic field, both producing changes of the magnetic leakage flux density by using B– H curves modeled according to a two lines approach.