The Effect of Oxidation-Induced Surface Transformations on the Anodic Polarization Characteristics of Fe Mn Si Alloys

High temperature oxidation of Fe Mn Si alloys results in the formation of a transformed surface layer that contains a lower concentration of manganese and a higher concentration of silicon than the underlying metal. Because the corrosion resistance of iron-silicon alloys is very sensitive to the concentration of silicon in the metal, the transformed layer is often more corrosion-resistant than the original alloy. Anodic polarization tests were used to demonstrate that a transformed layer with characteristics similar to those of a Fe-14.5 wt% Si alloy can be produced on an alloy with a low enough silicon content to permit mechanical forming.