| 摘要 |
PROBLEM TO BE SOLVED: To produce a grain-oriented silicon steel sheet excellent in magnetic properties by subjecting a high silicon-low carbon steel slab to hot rolling, thereafter subjecting the same to cold rolling for one time or plural times including process annealing and thereafter executing decarburizing annealing and final finish annealing. SOLUTION: A high silicon steel slab contg., by weight, 0.02 to 0.1% C and 2 to 4% Si is heated, e.g. at 1,400 deg.C and is subjected to hot rolling to work into a sheet material, which is thereafter subjected to cold rolling for one time or for plural times including process annealing at 1,050 deg.C for about 1min to form into a cold rolled sheet having a final sheet thickness. Next, this cold rolled sheet is subjected to decarburizing annealing to regulate the coating weight of oxygen in both sides of the cold rolled sheet to 0.7 to 2.0g/m<2> . Then, the surface of the cold rolled steel sheet is coated with a separation agent for annealing essentially consisting of MgO, contg. 0.03 to 1.5% SO3 and added and incorporated with the compounds of Ti, Sr, B, Zr or the like as assistants obtd. by subjecting Mg(OH)2 produced using seawater as a raw material to baking by a rotary kiln and pulverizing the same and is subjected to final finish annealing. The objective grain-oriented silicon steel sheet having excellent magnetic properties can easily be obtd. |
