Influence of the microstructure characterization and mechanical properties of C45 and C35 steels using magnetic Barkhausen noise technique

The aim of this work is to use Magnetic Barkhausen Noise (MBN) as a non-destructive evaluation technique for the microstructural analysis of C35 and C45 steels. In this sense, three different heat treatments were applied to these two steels to obtain different microstructures with different volume fractions of the constituents. Magnetic Brkhausen measurements have been performed using the MikroMach instrument. The results of this study demonstrate that not only are the Barkhausen noise measurements highly sensitive to the determination of carbon content and the state of internal stresses of two steels, but they also give a very precise idea of the constituents and the morphologies of the microstructures. Finally, the relationship between the various microstructures and magnetic hardness (Hc) and mechanical hardness (Hv) for each heat treatment is determined in this work.