2020. Vol.23. No. 3, pp. 50-56
Research and Evaluation of the Mechanical Anisotropy of Steel an Alloys by the Magnetic Noise Method
The mechanical anisotropy of the ferromagnetic materials properties predetermines the need for its study and evaluation, since it has a significant impact on the basic physical and mechanical characteristics of components, products and structures. Taking into account the relationship between the physical and mechanical properties of the material with the magnetic characteristics, to study the possibility of non-destructive testing of anisotropy the method of the Barkhausen effect was used, the informative parameters of which are magnetostructural and magnetoanisotropic. To study mechanical anisotropy a device for circular rotation of the Barkhausen transducer over the sample surface and a device for the production of elastic tensile / compressive stresses during static bending were made. Comparison of the results obtained using magnetic noises with the known coefficients of normal anisotropy of thin-sheet steel samples showed their qualitative and quantitative agreement, confirming the presence of a close relationship between them. It was found that elastic deformation in samples of anisotropic electrical steel leads to a sharp change in the level of magnetic noise and the type of circular diagrams, taking into account the sign of stresses. It is shown that as a result of cold rolling according to magnetic noise the samples have a pronounced texture due to the direction of rolling along the longest side of the sheet. The formed elastic deformation under tension and compression during static bending practically does not change the texture - the induced crystallographic anisotropy after rolling. The relationship between the intensity of magnetic noise and the degree of anisotropy is established and the possibility of evaluating the magnetic anisotropy in various steels and alloys using the Barkhausen effect method is investigated and confirmed.
Keywords: anisotropy, Barkhausen effect method, magnetic noise, elastic deformation, bending, tensile / compressive stresses, structure, inhomogeneity.