The use of quantitative analytical techniques to investigate the properties of steel artefacts is of great importance both in modern and historical metallurgy. A promising approach, but still not fully developed, is the use of neutron diffraction to quantitatively characterize the phase distribution and the micro-structural properties in a non-invasive way. In order to be able to exploit beyond any reasonable doubt this technique, it is necessary to compare the results obtained with analysis from more consolidated techniques in the field of metallurgy. For this purpose, we selected reference samples of certified carbon steel with different composition to be investigated with neutron diffraction. The reference samples will be analysed in three states: as received, after normalization, and after mechanical treatment. Rietveld refinement will provide multiphase and microstructural analysis.