The enhanced corrosion protection of Cr–Cu–Ni rail
compared to the C–Mn and Cu–Mo rail steel was correlated
to the higher amount of Fe3–xO4 (magnetite) and
presence of δ-FeOOH (goethite) in the rust. Photographs
of the rails along with the SEM photomicrographs (Figure
3), clearly indicate that the rust formed on the Cr–
Cu–Ni rail was more compact and therefore protective in
nature.