In this experiment, we propose to analyse a 17th century helmet from the Haruta School, whose armorers were suppliers of the Shogun and of the Imperial family until the 17th century. This sample has already been measured using neutron diffraction on the INES beamline, to determine the quality of the steel and to get semi-quantitative information on micro-structural properties. Information on the working procedure relative to thermal and mechanical treatments was inferred and the presence of a composite structure of steel and iron superimposed was supposed. In order to shed light on the last unresolved question, we propose to complete the cycle of neutron measurements on this sample, scanning the phase distribution of a few single plates along their section.