Experimental substantiation of diagnostic parameters used in metal magnetic memory method

Abstract

Tensile testing of steel specimens under 'soft' and 'hard' loading conditions with simultaneous measurement of the self-magnetic field of the specimens using the metal magnetic memory (MMM) method is performed. By comparing the obtained tensile diagrams with magnetograms of the self-magnetic field variation, the relationship between the magnetic and mechanical characteristics at different stages of loading is determined. It is found that the self-magnetic field variation magnetograms of the specimens closely correspond to the true tensile diagrams. The ratios between the magnetic and mechanical characteristics, obtained during tensile testing of the specimens, allow for the determination of the limiting state of the metal at the time of crack formation using the measured magnetic parameters in stress concentration zones when performing practical diagnostics of equipment.