The deterioration after excavation of archaeological artefacts buried in soil is often associated with the presence of chlorine ions which play an important role in iron corrosion mechanisms. The understanding of these processes, related to the presence of chlorine, has to be made towards a precise study of the morphological and physicochemical properties of the iron corrosion products. A characterisation study on ferrous artefacts coming from four archaeological sites has been carried out; the rust layers have been studied using several techniques. The composition analyses were performed by energy dispersive spectroscopy coupled to scanning electron microscope. Structural information has been obtained by micro X-ray diffraction, micro Raman spectrometry and micro X-ray absorption experiments. The results obtained illustrate the necessity of the combination of these different techniques for the detailed study about corrosion typology.