EXPERIMENTAL DETERMINATION OF THE ELECTRICALCONDUCTIVITY AND MAGNETIC PERMEABILITY OFDIFFERENT STEELS AND ITS APPLICATION TO THEPREVENTION OF STEEL MIXINGS IN A PIPE MILL

摘要

Eddy currents based equipments can be used to detect differences in electricalconductivity or magnetic permeability of metallic samples. In this work we deal with the problem ofdetecting eventual steel mixings in a steel pipe production line. The starting point of the analysis is thedevelopment of a technique to measure the electrical conductivity and the magnetic permeability ofsteel samples which allows to characterize completely the expected coil impedance at low excitationcurrents. At higher excitation currents the nonlinear/hysteretic behavior of the steel cannot bedisregarded. We present some preliminary measurements of hysteresis curves together with anumerical analysis of its influence on the anharmonicity of the coil output.