The influence of elastic deformation on the properties of the magnetoacoustic emission (MAE) signal for GO electrical steel

Magnetic properties of the grain oriented (GO) electrical steels are strongly affected by the stresses, both external and internal. The change is important even for the deformation resulting in stress level much lower than their yield limits. In this paper we present the results of investigation of the influence of compression and tension on the magnetoacoustic emission (MAE) signal properties. The experiment was performed with the help of bending machine in which the samples (0.3 mm thick, M140-30 S GO electrical steel) glued to the non-magnetic (austenitic steel) 8 mm thick bars were bent. The samples cut out in two directions (parallel and perpendicular to the rolling direction) were investigated. The elongation was measured directly with the help of tensometric bridge. Various parameters of the MAE signal, such as e.g. signal intensity and MAE peaks separation, have been examined.

► Magnetic properties of the GO electrical steels are strongly affected by stress.
► The non-destructive method of investigation of the ready-made components is needed.
► Magnetoacoustic emission is sensitive to stress-induced domain structure changes.
► Advanced signal analysis allows to determine the stress level in an unambiguous way.