Abstract: The present invention relates to a method for detecting temporally varying thermomechanical stresses and/or stress gradients over the wall thickness of metal bodies, in particular pipelines. In the method, the temperature on the outer surface of the body is measured in order to determine a temperature progression and stress progression therefrom. In addition, electromagnetic ultrasonic transducers are used at at least one measuring point on the outer surface in order to determine the progression of the stresses and/or stress gradients over time over the wall thickness of the body in conjunction with the result of the temperature measurement. The method allows the fatigue monitoring of pipelines even in the event of rapid stress changes.

Abstract: The present invention relates to a method for detecting temporally varying thermomechanical stresses and/or stress gradients over the wall thickness of metal bodies, in particular pipelines. In the method, the temperature on the outer surface of the body is measured in order to determine a temperature progression and stress progression therefrom. In addition, electromagnetic ultrasonic transducers are used at at least one measuring point on the outer surface in order to determine the progression of the stresses and/or stress gradients over time over the wall thickness of the body in conjunction with the result of the temperature measurement. The method allows the fatigue monitoring of pipelines even in the event of rapid stress changes.

Abstract: A method is described for non-destructive material testing on a workpiece comprising an electrically conductive material using EMUS transducers, each of which has a magnet unit for locally introducing a magnetic field into the workpiece, and also has a radio frequency (RF) coil arrangement, which interacts with the magnetic field. The invention is distinguished in that at least two transcuers are spaced apart along a surface of the workpiece. At least a first EMUS transducer generates and also measures ultrasound waves within the workpiece and the second EMUS transducer functions as a reception transducer for at least detecting ultrasound waves.

Abstract: A method for welding workpieces where at least two workpieces are welded together by means of friction stir welding, at least one of the workpieces being treated with ultrasound during the welding.

Abstract: In a process and an apparatus for determining the coercive field strength and the maximum pitch of the hysteresis cure in set-up techniques a test body is magnetized in a magnetic field of an exciter coil fed with an alternating current, as the hysteresis curve of the test body is traversed a number of times with the frequency of the alternating current and the tangential field strength on the test body surface generated by the exciter coil is detected continuously with the aid of a magnetic field strength sensor during the traversing of the hysteresis curve. From a harmonic analysis of the time course of the tangential field strength within one period there is calculated a distortion factor for the determination of the maximum pitch of the hysteresis curve.