Eddy current nondestructive evaluation of dual phase steel

This study proposes eddy current testing (ECT) as a tool for nondestructive material characterization. In the present study, different dual phase steels (DPSs) with different martensite phase percentages were manufactured using various intercritical annealing temperatures (from 745 to 890 °C). The aim of the present study is to correlate ECT outputs with the different percentages of martensite and find a relation for determination of martensite percentage of any unknown DPS sample. Increasing the intercritical annealing temperature leads to an increase in the percentage of martensite in DPS, which it caused to a decrease in magnetic permeability of DPS and subsequent decreasing of ECT outputs. Mechanical properties of DPS specimens can also be predicted by the means of ECT. The study revealed that a good correlation exists between ECT outputs and microstructural and mechanical changes in the DPS specimens (R2 > 0.85) and it shows potential of using ECT for prediction of material properties in the DPS.