For neutronographic residual stress analysis it is essential to provide correct reference data of the strain free material state, i.e. the lattice parameter D0. There exists an increased interest for non-destructive determination of near surface residual stress gradients for the application of neutron diffraction stress analyses by means of through surface strain scanning. Causal for residual stress gradients are often processes that induce a chemical gradient of the lattice parameters like e.g. nitriding or case hardening of steel. Moreover, the most technical materials are multi-phase materials. This in total leads for thermal and/or mechanical treatment processes to specific gradients of the phasespecific micro residual stresses. With regards to the preparation of samples to determine the local depth distribution of D0 it is mostly unknown if the residual stresses are sufficiently released through the mechanical sectioning for that they can be regarded as being ´stress free´. This problem and the effect of local distributions of phase specific micro residual stresses on the lattice parameter D0 will be the focus of the herein proposed research project.