| 摘要 |
The invention relates to a method for determining a mechanical-technological characteristic value of ferromagnetic metals, preferably ferromagnetic steels and in particular fine-grained steels, which are used in pipelines, wherein a magnetizing device having at least one permanent magnet or electromagnet (17) magnetizes the metal to be determined and a sensor device (11) comprising a transmitting coil (24) produces a magnetic field, which interacts with the magnetic field produced in the metal by the magnetizing device and produces an eddy current, wherein the eddy current is produced in the magnetically at least substantially saturated metal and the eddy current is measured by an eddy-current sensor of the sensor device (11), wherein a magnetic-field-strength sensor (12) measures the magnetic field of the metal at least close to the surface, and wherein, by means of an evaluating device (43), the electrical conductivity or the specific resistance of the metal is determined from the data of the eddy-current sensor on the basis of reference data and the characteristic value of the metal is derived from the conductivity or the resistance. The invention further relates to an inspection pig for performing such a method. |
