Method for estimation of magnetic viscosity of ferromagnetics

A method providing quantitative estimation of the degree of magnetic viscosity of ferromagnetic materials by measurement of the phase of the signal from the measuring coil at field excitation by a sinusoidal signal in longitudinally extended samples with constant cross section is described. It is demonstrated that, in estimation of magnetic viscosity, it is necessary to take into account the sample size and shape, as well as the frequency of measurement. Additional information obtained by determination of the decrement of the signal from the measuring coil can be used together with the magnetic viscosity for determination of steel grade. Corresponding plots are presented.