Applicability of Magnetic Measurements to the Detection of Fracture Nucleation in 09G2S Steel

The paper presents results of local magnetic measurements at various regions of two 09G2S steel specimens plastically deformed by uniaxial tension. The first specimen was deformed to crack formation, while the second was deformed to the initiation of necking (before the initiation of strain localization). Magnetic characteristics were determined in both the major magnetization reversal cycle and the minor magnetization reversal cycles in medium and weak fields. The fundamental possibility of applicability of locally measured magnetic properties of plastically deformed steel products in the minor magnetization reversal cycles in medium and weak fields to the detection of potential nuclei is experimentally demonstrated. It is shown that the presence of peaks, their magnitudes, and the magnetic field strengths at which they form on the field dependence of differential magnetic permeability can be used to obtain information about the strain corresponding to the test object region.