Evaluation of the Proportion of Phases and Mechanical Strength of Two-Phase Steels Using Barkhausen Noise Measurements: Application to Commercial Dual-Phase Steel

The possibility to assess the relative proportion of phases and the mechanical strength in two-phase steels by means of Barkhausen noise measurements has been studied. It was found that the amplitudes of the Barkhausen peaks are directly proportional to the relative proportion of the corresponding phases. We have shown that the peak amplitude can be used to assess not only phase proportion but also its magnetic field position. These conclusions were drawn for ferrite-martensite steels with different proportions and compositions and also for spheroidal graphite cast iron composed of ferrite-martensite and ferrite-bainite phases. We also applied these results to different grades of commercial dual-phase (DP) steels, thereby confirming the possibility to assess phase proportion and mechanical strength using this nondestructive magnetic technique.