NONDESTRUCTIVE EVALUATION OF MECHANICAL PROPERTIES OF DUCTILE CAST IRON PARTS USING EDDY CURRENT SIGNALS

The present research investigates improvement of Eddy Current (EC) technique as a nondestructive method for measurement of ductile cast iron microstructural and mechanical characteristics. Six samples of heat treated ductile cast iron have been selected to study the relations between pearlite content and EC outputs. These outputs include voltage and normalized impedance as well as calculated parameters of harmonic analysis. Furthermore, correlation between mechanical properties such as hardness, yield strength and ultimate tensile strength in samples containing different ferrite-pearlite matrices and the magnetic responses has also been found. High correlation coefficients of the relations indicate an acceptable level of accuracy in comparison with destructive method.