Application of Fe oxide films prepared by PVD methods to protect Fe metal from corrosion

α-Fe2O3 films on Fe substrates were prepared to protect the substrates from corrosion by thermal evaporation (TE) and electron shower (ES) methods. The TE sample, which was immersed in 3 wt.% NaCl solution, peeled off at the pinholes and the size of pinholes increased. The sample was corroded near the pinholes above 24 h of immersion time. However, it was found that the ES sample was not corroded at all. This is caused by the FeO formation on the pinholes by the ES. The thickness of the FeO layer was estimated at 4 nm.