Abstract: The present invention provides a method for determining biaxial stresses in a steel component by first generating a calibration datum from an experimental test piece having metallurgical properties similar to steel component and then applying values representative of measured Barkhausen noise levels obtained from the steel component to the calibration datum. The practice of the present invention yields values of strain in the first and second principal directions at the selected location on the steel component under examination.

Abstract: A sensor for a system that detects stresses and defects in a metal piece by employing the Barkhausen phenomenon enables static or dynamic testing of such metal pieces as hard steel in which only low levels of Barkhausen noise can be generated or which are configured in one of a large variety of shapes. The sensor includes apparatus that ensures that a uniform time-varying magnetic field can be produced in all the metal pieces of a variety of shapes. The sensor can include an energizing coil assembly which generates the magnetic field in the metal piece having a core constructed from such a material in which a low level of magnetic noise is generated as ferrite. The level of the magnetic noise generated in the ferrite core is so low that, even if the magnetic noise is sensed by the sensing coil assembly, which receives the Barkhausen noise gererated within the metal piece, that noise cannot interfere with the higher levels of Barkhausen noise generated in all ferromagnetic metals, including hard steel.

Abstract: A method for analyzing the anisotropic properties of ferromagnetic steels by use of Barkhausen noise simultaneously sensed in a plurality of directions without contact with the steel specimen.