The formation of ε-Fe3–2N phase in a nanocrystalline Fe

The formation kinetics of e-Fe3–2N phase in a nanocrystalline α-Fe, which was processed by surface mechanical attrition treatment, is found to be obviously increased with respect to that in the coarse-grained form. This can be attributed to the much enhanced heterogeneous nucleation rate at numerous grain boundaries in the nanocrystalline α-Fe.