The effect of tempering on the magnetic Barkhausen noise (MBN) signal profile was
studied in case-carburised EN36 steel using a range of
magnetic excitation frequencies and a number of frequency ranges for analysis of the
MBN signal. The MBN level generally increases with
tempering due to coarsening of the microstructure. With higher values of excitation
frequency, fEX, the MBN profile exhibits a single peak,
but with low values of fEX, double peaks are observed.
