Preliminary study: Barkhausen noise evaluation on the Hardening Depth of Induction-hardened carbon steel

Induction hardening depth evaluation by means of Barkhausen noise (BN) technique is one known non-destructive evaluation (NDE). The acquired signal, nevertheless, is not easy to be interpreted owing to information and materials complexity. Current study is initiated from a case in local industry about the quality control of induction hardened camshaft. Certain historical BN data is reviewed, and hypothetical hardening conditions are simulated in order to find out a possible relationship between the acquired signal and the microstructure of the hardened layer. Selected physical properties of these simulated hardened layers were evaluated. Using these data, physical modelling was developed by means of finite element method (FEM). A magnetising unit is modelled and the induced magnetic flux density in the material is simulated. Modelling results were then compared with experimental study. The project work is at the preliminary stage and it is expected that the ultimate model will help to improve the understanding of the BN signal in relations to the induction-hardened depth evaluation