Determination of austenite vs. α-ferrite in steel by neutron and x-ray diffraction

Neutron and X-ray diffraction studies for deteririning the relative content of fee (austenite) and bec (a-ferrite) phases in steel samples are reported. In addition to determine the relative content of phases the diffraction method also provides
information about the strain fields in the sample by the concomitant broadening of diffraction peaks. Neutron diffraction has the advantage that large sample volumes (several cc) are probed, and the effect of texture can thus be eliminated. X-ray diffraction patterns can be registered in a short time thus allowing kinetic studies of phase changes during heat treatment or mechanical treatment. In addition it is possible to probe different surface thickness by utilizing different X-ray wavelengths. Measurements of this type can be carried out on a commercial contract basis in the Solid State Physics Division at Risø National Laboratory.