Estimation of residual stress in cold rolled iron-disks from strain measurements on the high resolution Fourier diffractometer

The results of estimating residual stresses in cold rolled iron disks by measurements with the high resolution Fourier diffractometer (HRFD) at the IBR-2 pulsed reactor are presented. These measurements were made for calibration of magnetic and ultrasonic measurements carried out at the Fraunhofer-Institute for Nondestructive Testing in Saarbrucken (Germany). The tested objects were cold rolled steel disks of 2.5 mm thickness and diameter of about 500 mm used for forming small, gas pressure tanks. Neutron diffraction experiments were carried out at the scattering angle 2θ=+152deg with resolution Δd/d=1.5·10-3. The gauge volume was chosen according to the magnetic measurements lateral resolution 20x20 mm2. In the nearest future the neutron diffraction measurements with cold rolled iron disks at the scattering angle 2θ=±900 are planned. Also the texture analysis will be included in the Rietveld refinement procedure for more correct calculation of residual stress fields in the cold rolled materials. 8 refs., 10 figs., 1 tab