| 摘要 |
PURPOSE:To enable production of a silicon steel sheet having an excellent magnetic flux density and iron loss characteristic in producing a grain-oriented silicon steel sheet by applying and baking a coating liquid contg. a specific slight amt. of Ce on the steel sheet upon ending of secondary recrystallization. CONSTITUTION:A slab as a raw material for a grain-oriented silicon steel sheet contg. 2.0-4.0% Si is hot-rolled and worked to a hot-rolled sheet. After the hot- rolled sheet is subjected to uniform annealing, the sheet is subjected to >=2 times of cold rolling including intermediate annealing at 950 deg.C to be made into a final cold-rolled sheet having 0.3mm. thickness. The cold-rolled sheet is then subjected to decarburizing and primary recrystallization annealing in an H2 atmosphere and thereafter an annealing separating agent consisting essentially of MgO is coated thereon. Such sheet is subjected to secondary recrystallization annealing at 850 deg.C followed by purification annealing in an H2 atmosphere at 1,200 deg.C to remove harmful impurities such as C, N, etc. and to form a forsterite insulating film. A coating liquid contg. 0.001-1.0% compd. such as CeO2, Ce(NO3)2, etc. in terms of Ce and consisting essentially of phosphate and colloidal silica is applied thereon and is baked. |
