Abstract: Specimens of Fe15Si silicon steel were oxidized at 1000~1200℃ in air for 30min.At 1000℃ and 1100℃ fayalite was observed at the scale/substrate interface.While at 1200℃ fayalite was found both at the scale/substrate interface and at the outer oxide layer. Then after the singlepass hot rolling process， with the compression ratio of 10% and 30%， it was found that at 1000℃ and 1100℃， higher compression rate accelerated the broken of the scale layers， but the scale structure was not affected by the hot rolling process， while for the specimens oxidized at 1200℃， because of the formation of liquefied fayalite， the fayalite was squeezed into the outer oxide layer in the singlepass hot rolling. Pinning effects were weakened at the scale/substrate interface， and flatness of the interface between the scales and the substrate was improved.

Key words: oxide scale, silicon steels, hot rolling, fayalite, morphology