Comparative study of eddy current and Barkhausen noise methods in microstructural assessment of heat treated steel parts

Journal: Nondestructive Testing and Evaluation

Publication date: 29 Apr 2014

Abstract:

The present paper describes details of the comparison on the capability of eddy current (EC) and magnetic Barkhausen noise (MBN) techniques in the assessment of different microstructures in mild steel. To produce various microstructures, AISI 1045 steel samples were subjected to different heat treatment processes including annealing, normalising, quenching and tempering. EC outputs (induced voltage, normalised impedance and phase angle) as well as MBN outputs (peak width, position and amplitude) were evaluated. Comparing the EC/MBN outputs for the microstructures, the MBN peak characteristics show better agreement with changes in the microstructures. Besides, using regression analysis, peak width has been proved to be the optimum output to separate the microstructures with high accuracy.