Structure and phase transformation of iron surface layer treated by compression nitrogen plasma flows

Investigation on a surface structure of iron modified by the action of compression plasma flows and determination of element and phase composition was carried out using X-ray diffraction analysis, Auger-electron spectroscopy, optical microscopy and scanning electron microscopy, along with studies on mechanical properties of the material. As a result, a layered structure of total depth up to 60 μm with nitrogen concentration up to 20 at.% develops at a sample surface. The final structure of near-surface area in the processed iron was shown to be formed from the ε-domain due to eutectoid decomposition on cooling, whereas an increase in both hardness and wear resistance results from dispergation of phase components.