Research of the effect of biaxial mechanical loading on the magnetic characteristics and harmonic spectrum of 65G spring steel

The paper presents the results of research and mathematical modeling of the effect of biaxial mechanical loading on the magnetic characteristics of spring steel 65G. Determination of the magnetic characteristics of the steel sample included registration of the magnetic hysteresis loop, the harmonic spectrum of which was analyzed under various combinations of external load. It was found that relatively homogeneous tensile stresses act on the specimen in the area of magnetic parameters measurement. The distribution of loads along the cross-sections of the specimen shows that under uniaxial stretching along the horizontal or vertical axis the character of the stress distribution does not change, provided that there is no sharply pronounced anisotropy. It is also revealed that an increase in the external biaxial tensile load leads to a decrease in the recorded values of the coercive force. However, at uniaxial loading the coercive force value grows and sharp changes in the values of the considered harmonic components are observed (load about 50 MPa), which can speak about the processes of redistribution of internal residual stresses in the specimen. The obtained results can be used in ensuring safe operation of equipment elements made of spring steel, as well as serve as a basis for the development of a magnetic method for evaluating the acting loads of a complex type.