Investigation of the magnetic signals for the ferromagnetic components after tensile fatigue under weak magnetic excitation

In order to investigate the magnetic signals on the surface of the ferromagnetic component, which have suffered the tensile fatigue under weak static magnetic excitation, an experiment is set up to operate the research. The 16MnR is adopted to make the specimen which will get the tensile fatigue, with a prefabricated small crack in the center position of it. The probe based on the GMR Array is engaged in the signal acquisition system. Magnetic signals at different tensile stage is obtained and mapped, as well as its gradient. Research between the characteristics of the signals and the specimen's suspicious stress concentration or damaged area has been discussed to make a proper evaluation to the components.