The Use of EBSD to Study the Microstructural Development of Oxide Scales on 316 Stainless Steel M.Jepson a and R.L.Higginson b IPTME: Institute of Polymer Technology and Material Engineering, Loughborough University, Loughborough, Leicestershire. LE11 3TU Keywords: EBSD, stainless steel, oxide scale Abstract: 316 stainless steel has been oxidised at 1200ºC in air for varying times and with different cooling rates. The resulting scales were examined using optical and electron microscopy techniques including electron backscatter diffraction (EBSD) and energy dispersive spectroscopy (EDS). It was found that the scales on a sample oxidised for 4 hours consists of three layers; the lowest layer is a fine equiaxed region which has a uniform distribution of chromium which is similar to the base metal, followed by a larger equiaxed layer with very little chromium content but a high iron content, with a final layer of columnar grains of which some are rich in nickel. With a slower cooling rate a large amount of internal oxidation within the metallic substrate was observed which showed a chromium content higher than the oxidised metal. Introduction Exposing steels to high temperature conditions such as those during manufacturing and forming processes causes them to oxidise. The study of the oxide scales formed is important to manufacturers as their presence can affect the friction, heat transfer and wear of the rolls during hot rolling [1, 2]. This study has been carried out to examine the scales formed during the reheating of stainless steels. Currently these scales are removed by a combination of mechanical and chemical descaling before rolling; if some scale is still present it can be detrimental to the final rolled product’s