Texture Transition in Steel ST37K, in situ Measurement at High Temperatures Using High-Energy X-rays

Abstract

High energy X-rays are well known due to there high penetration power particular in materials testing devices. For diffraction experiments high energy X-rays with more than 50 keV can be obtained at storage rings or using a tungsten X-ray tube. According to the high penetration power, these beamlines offer a very high photon flux and an excellent brilliance. That means measurements can be carried out fast. As an example, the complete texture measurement at one position of a steel shaft with 34 mm in diameter has taken 45 minutes nondestructively. On the other hand the high photon flux allows to measure foils or thin wires down to 50-100 µm. These new and fast options make it possible to measure in situ textures under tension, compression and at high temperatures. We have used 100 keV X-ray to measure the texture transition as well as the phase transition in a steel sample. The experiments were done at the high energy beamline BW5 (Hasylab at Desy/Hamburg). 100 keV X-rays have a wavelength of 0.1240 Å which means due to the Bragg's law very low scattering angles. Using a MAR345 image plate detector one obtains a set of complete Debye-Scherrer cones in a 2ș-range of 7° in about 1 sec. At room temperature we found 100% ferrite. During heating up till the austenite region we were able to investigate the thermal expansion and the texture relation between ferrite and austenite, which follows in our case the Kurdjumov-Sachs model. Furthermore, the program pack-__________________________________

Investigation of Texture Gradients of Semi-Finished Products by Neutrons and Photons

“…Fig.8: From area detector data to pole figures a) area detector information for one sample position; b) information of one Debye-Scherrer ring inside a stereo graphic projection; c) needed sample rotations to cover pole figures; d) (111) pole figure of rolled Al The following example describes the flexibility of synchrotron investigations for standard pole figure measurements, see fig 9, showing a steel shaft of 34 mm thickness (fig.9a and 9b) and a thin Fe foil of 10 µm thickness[14]. That means in practice, one needs a set of special sample holders.…”