Image Number 3 for United States Patent #5261971.
A silicon steel slab comprising 0.05 to 0.8% by weight of Mn and up to 0.014% by weight of S+0.405Se is heated at a temperature lower than 1280.degree. C. and hot-rolled under such conditions that the hot rolling-finish temperature is 700.degree. to 1150.degree. C., the cumulative reduction ratio at the final three passes is at least 40%, and the reduction ratio at the final pass is at least 20%, or this silicon steel slab is hot-rolled at a hot rolling-finish temperature of 750.degree. to 1150.degree. C. while adopting the above-mentioned reduction ratio according to need, is maintained at a temperature not lower than 700.degree. C. for at least 1 second, and wound at a winding temperature lower than 700.degree. C. The hot-rolled sheet is subjected to the hot-rolled sheet annealing, finally cold-rolled at a reduction ratio of at least 80%, subjected to the decarburization annealing, and then subjected to the final finish annealing. According to this process, a grain-oriented electrical steel sheet having superior magnetic properties is obtained.