Difference in corrosion behavior between pure iron and carbon steel after short-time exposure test

Difference in corrosion behavior between pure iron and carbon steel in short-time exposure test was examined in detail by electrochemical methods. Though the corrosion resistant of pure iron was better than that of carbon steel after 1month-exposure test, the amount of corrosion of pure iron was more than that of carbon steel after 6month-exposure test. By various electrochemical methods, it was indicated that oxide film on pure iron was different from that on carbon steel. It was found that the oxide film on pure iron was difficult to destroy by chloride ions in comparison with that of carbon steel, as a result of examining the effect of chloride ions on the oxide film. On the other hand, from X-ray diffraction and reduction measurement of the rust, it was indicated that the amount of FeOOH that was reduced to magnetite easily was abounding in the rust of the pure iron in comparison with that of the carbon steel.