Characterization of nanocrystalline ferrite produced by mechanical milling of pearlitic steel

Three-dimensional atom probe analysis of the nanocrystalline ferrite produced by mechanically milling pearlitic steel indicated that carbon atoms are strongly segregated at the grain boundaries, and approximately 1.0 at.% carbon are dissolved in the nanocrystalline ferrite. Annealing at 400 °C led to the rejection of carbon from the grains and the precipitation of cementite at the grain boundaries, while the nanocrystalline microstructure was retained.