There have been many investigations into the development of an alternative environment-friendly method to replace the hard chrome plating, which produces toxic effluents such as hexavalent chromium. Post-oxidation process has been performed on a plain carbon steel (AISI 1045) to improve corrosion resistance properties for automobile parts. Three different post-oxidation processes have been used such as conventional steam oxidation, O2 plasma oxidation and O2 gas oxidation. For the comparison of substitute processes of steam, plasma and conventional oxidation with hard chrome plating, glancing angle X-ray diffractometer (GAXRD), scanning electron microscope (SEM) and potentiostat have been used to investigate the phase, morphologies and corrosion properties. O2 plasma oxidation and O2 gas oxidation processes showed relatively improved corrosion properties of higher pitting potential and initial corrosion potential.