Magnetic evaluation of Bauschinger effect in marine engineering steels

Abstract

In the present study, the association between the magnetic behavior of steels the Bauschinger effect was evaluated. For this reason, three different grades of steel were subjected to typical Bauschinger tests involving a single reversal from tension to compression loading, for the same amount of pre-strain. The reversal compression lasted until the opposite of the pre-strain's maximal stress was reached. As a nondestructive magnetic technique for determining the magnetic properties of the examined samples, magnetic Barkhausen noise was chosen. For the characterization of the Bauschinger effect, four indicators were used, in terms of strain, stress, and energy. Mechanical stresses alter material magnetization, but linking Bauschinger factor with magmatic noise parameters has not been widely studied. Comparing Bauschinger Effect parameter values and magnetic Barkhausen methods, results show consistency with ferromagnetic samples' mechanical behavior. As Bauschinger Effect becomes more forceful, disorder density and magnetic wall anchoring decrease. A new proposed parameter, the exponent ξ, is directly related to effect rate. The magnetic Barkhausen noise method and its peak position and full width half minimum parameters can be a promising complementary measure for evaluating BE contribution in cycle loading ferromagnetic steels. Finally, the applicability of the examined techniques for the non-destructive characterization of steel degradation was discussed.