Oxide Scale Growth on High Carbon Steel at High Temperatures

The structure and formation process of oxidation on high carbon steel were investigated with the aid of X-ray diffraction (XRD), scanning electron microscope (SEM) and Laser Raman spectroscopy (LRS). The oxide scale formed comprised a three-layer structure, similar to that formed on pure iron and low-carbon steel. For the high carbon steel, however, the scale was essentially a two-layered because of the low proportion of hematite (Fe2 O3) formed. The scale thickness increased with the temperature and time of oxidation. The rate of scale thickening rapidly increased above 900 °C, at which the rate was particularly fast in the first 20 s of oxidation. The proportion of wüstite (Fe1-y O) increased with time and temperature of oxidation, while the magnetite (Fe3 O4) remained constant at about 2 μm.