Even if numerous techniques are already used in order to characterize multi-phase steels, it seems to be difficult to obtain specific information provided by each phase. In this context, magnetic Barkhausen noise measurements have been used in order to characterize metallurgical transformations in multi-phase High Strength (SH) steels. We identified specific responses for ferrite or pearlite, bainite and martensite constituents and the main parameters influencing the Barkhausen response. We show that it is possible, first to quantify the proportion of granular ferrite in ferrite-martensite or in industrial DP steels and second to identify the main metallurgical transformations during an isothermal holding of a TRIP steel.
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