Characterization of deformation-induced martensite by cryogenic turning using eddy current testing

 The formation of deformation-induced martensite upon cryogenic turning results in a substantial hardening of the surface. In this study, eddy current testing was used to gain a deeper insight in the microstructural evolution. Electromagnetic simulations were used to separate the various contributions to the measurement signal. The overall martensite content is strongly correlated with the measurement signal. However, the actual  martensite structure also affects the signals. Thus, eddy current testing not only has the potential to control the evolution of the martensite content during the cutting process but also can provide information about the finer details of the martensitic microstructure.