Structure and mechanical properties of iron after surface severe plastic deformation under friction with simultaneous nitrogen saturation: II. The mechanical properties of nano- and submicrocrystalline iron saturated with nitrogen during deformation

Abstract

Abstract-The effect of structure refinement of iron to submicro and nanograins during intense plastic deformation under friction (SPDF) with simultaneous nitrogen saturation on the mechanical characteristics (hardness, plasticity, Young's modulus) has been studied by nanoindentation. The nitrogen saturation of iron during SPDF is shown to increase the hardness of micro and submicrocrystalline regions of the surface layer as compared to SPDF in argon as a result of solid solution hardening. A high nitrogen concentration in an α Fe[N] solid solution weakly affects the mechanical properties of nanocrystalline iron with grain sizes d < 50 nm, in which deformation is controlled by grain boundary sliding.