Dissolution of the Fe4N nitride in the nitrided layer of iron upon cold deformation by shear under pressure

Mossbauer spectroscopy, X-ray diffraction, and transmission electron microscopy were used to study structural and phase transformations upon cold (300 K) deformation by shear under pressure in thin layers of nitrides Fe4N formed on the surface of bcc iron. Strain-induced dissolution of nitrides in bcc iron with the formation of bcc and fcc solid solutions supersaturated with nitrogen and secondary Fe16N2 and Fe4N nitrides was found. The dispersiveness of nitride phases in the layers deposited on bcc iron determines the accelerated kinetics of cold mechanosynthesis and the possibility of the formation of nanocrystalline iron-based solid solutions supersaturated with nitrogen and containing secondary nitrides.