V&m Deutschland Gmbh

Vallourec Deutschland Gmbh

Salzgitter Mannesmann Line Pipe Gmbh

Europipe Gmbh

Michael Kaack

Stefan Nitsche

Alfred Graff

Gert Fischer

Jörn Winkels

Thomas Orth

Holger Brauer

Ashraf Koka

Ludwig Oesterlein

Christian Kremer

Franz Martin Knoop

André Germes

Sven Gwildies

The invention relates to a method for testing connections of metal workpieces to plastic compounds for cavities by means of ultrasound, wherein the plastic compound is arranged between the workpiece as an intermediate layer or is connected to the workpiece on one side and the cavity is located within the plastic compound, wherein the cavity is connected to the workpiece by means of a remaining plastic layer or plastic skin and wherein the plastic compound is exposed to ultrasonic signals of a certain test frequency and pulse length from the metal side of the workpiece by means of at least one ultrasonic probe, and in particular the ultrasonic signals reflected by flaws in the plastic compound are detected by the same or another ultrasonic probe and converted into electrical signals that can be evaluated and subjected to a threshold observation. The test frequency of the ultrasonic signals is set in a range of 1 to 10 MHz so that the attenuation of the sound is minimal after passing through the plastic skin.

Method for testing connections of metal workpieces to plastic compounds for cavities by means of ultrasound

In a method for producing welded pipes from steel, in which strips or metal sheets are formed into a pipe provided with a longitudinal or helical slot and the abutting edges of the slotted pipe are welded together, the process parameters for production of the pipes are specified on the basis of previously ascertained material properties and geometry of the strips or metal sheets. Before the forming process, the strip or metal sheet is subjected to an nondestructive, continuous or discontinuous test for inhomogeneities over the length and width, an integral characteristic value for the material property of the strip or metal sheet is formed from the measured values, a measure of the homogeneity of the material properties relating to the length and width of the strip or metal sheet is derived from the variance in the measured values for the various measurement points and, in the event of deviations in the measured values exceeding previously specified limit values, the process parameters are reset and/or the strip or metal sheet is subjected to a homogenisation process prior to the forming process.

Method for producing welded tubes from steel

The invention relates to a method for the automated measurement of the residual magnetic field strength of magnetized ferromagnetic workpieces, especially steel tubes, the residual magnetic field exiting the face of the tube end being measured by means of a measuring probe. Instead of directly measuring the residual field strength on the face, the curve of at least one magnetic field component is measured on the outer surface of the tube at least in the region of the tube ends and beyond the tube ends and the residual field strength on the face is inferred on the basis of the previously determined correlations between the residual field strength measured on the face and on the tube surface.

Method for automated measurement of the residual magnetic field strength of magnetized ferromagnetic workpieces

A device for nondestructive testing of a pipe made of ferromagnetic steel for detection of longitudinal, transverse or inclined flaws using magnetic or magnetic-induction test procedures is disclosed. The device includes a magnetizing yoke which transmits the magnetic flux contactless into the pipe and at least two magnetic-field-sensitive scanning probes having GMR sensors. The GMR sensors are combined into sensor groups in form of a sensor array and electrically connected in parallel. A single preamplifier connected to each sensor group in one-to-one correspondence. The device further includes an evaluation unit.

Device for nondestructive testing of pipes

The present invention pertains to a method for the nondestructive testing of pipes made of ferromagnetic steel by means of a stray flux, in which the pipe, which is moving in the longitudinal direction and alternatively additionally rotating, is magnetized by a constant field, and the generated magnetic flux is transmitted into the pipe in a contactless manner, and the flaws that are located in the near-surface area of the outer or inner surface of the pipe bring about magnetic stray fluxes, which emerge from the pipe surface and are detected by means of sensors. The amplitudes, preferably of the horizontal field component of the magnetic stray flux, which vary in the vertical direction, are detected, on the one hand, at a near-surface distance from the pipe outer surface, and, on the other hand, at a distance lying further remotely therefrom, and the detected signals are related to one another.

Method and device for testing pipes in a non-destructive manner

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Bochum, Germany

Michael Kaack