A method for detecting defects on the surface of a ferromagnetic MATERIALS AND PRODUCTS AND DEVICE FOR ITS IMPLEMENTATION

摘要

1. A method for detecting defects on the surface of the ferromagnetic materials and products, comprising a supply to control the magnetic field to the object and recording of electrical signals caused by the magnetic leakage flux occurring at the defect, wherein the magnetization control object or part thereof produce two unipolar or polar magnetic pulses field, and further comprising an acoustic delay of electrical signals due to the interaction of magnetic pulses to the defect, and the minimum value of this delay must satisfy the condition: τ≥To where fact - the effective duration of the magnetic field pulse applied to study the control object, and as, at least part of the twin-turbo acoustic delay lines used kontrolya.2 object itself. Method of detecting defects on the surface of the ferromagnetic materials and products according to claim 1, characterized in that the acoustic delay effected by transformation of the energy of the magnetic pulse interacting with a defect in the elastic energy of Rayleigh waves propagating on the surface of the inspection object at a distance R, and the reception it with the ultrasonic transducer, and recording of electrical signals caused by the interaction of magnetic pulses with the defect is carried out usually at a frequency N times higher than in the fundamental frequency spectrum of the pulse magnetic field applied to the control object, where N = 2,3,4 ... 3. An apparatus for detecting defects on the surface of ferromagnetic materials and products containing settling VBL