LAUSR

Abstract In order to study the effects of magnetic memory signals affected by the external magnetic field, the magnetic domain model is used herein to quantify the distribution characteristics of the surface of the magnetic signals linked to the stress concentration areas. By using the method of finite element (FE) analysis, the magneto-mechanical model of X70 pipeline steel was deepened. The change in the rules of magnetic signals in the stress concentration areas subjected to different external magnetic fields was calculated and analyzed, while the systematic research of the experiments was carried out. Research results show that: under the geomagnetic field, there is a one to one linear corresponding relationship between the degree of the stress concentration and the magnetic memory signal. The magnetic memory signal along the different directions changed with the increase of stress, while the trends were different. The ferromagnetic metal components were unsaturated whether the intensity of the external magnetic field was weak, while the intensity of the magnetic field increased with the increase of the magnetic memory signal although the slope of the magneto-mechanics curve decreased. The ferromagnetic metal components were saturated whether the intensity of the external magnetic field was strong, while the magnetic signal on the stress concentration areas was covered and undetectable.