Dresden 2011 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 16: Structural Materials

MM 16.6: Talk

Tuesday, March 15, 2011, 12:15–12:30, IFW D

Conical slits for depth-resolved stress measurements with high-energy X-rays — •Torben Fischer, Peter Staron, Eike-Henning Eims, Sebastian Frömbgen, Norbert Schell, Martin Müller, and Andreas Schreyer — Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Geesthacht, Germany

The use of photons with energies from about 50 keV up to about 150 keV and the resulting large penetration depths enables diffraction measurements in the bulk of the material and, thus, to obtain information e.g. on residual stresses even within larger components. The depth resolution that is required for such measurements can be achieved by the use of a conical slit system in the case of monochromatic radiation. Such a system was tested at the new high-energy material science beamline HEMS of the Helmholtz-Zentrum Geesthacht at the new PETRA III synchrotron at DESY, Hamburg. The samples used for the test were laser beam welded (LBW) steel sheets. The LBW technique is currently still being developed for applications in civil aircraft production and automotive industry for reducing weight and production costs. The LBW introduces residual stresses in the weld and heat affected zone. These stresses can have disadvantageous influence on the service performance of the weld. LBW overlap joints of DC04 steel with a thickness of 2 mm were investigated by this technique and the results were compared with the results of neutron diffraction measurements.