| 摘要 |
PURPOSE:To industrially obtain the steel strip capable of obtaining high magnetic flux density by combining a decarburized, annealed and primarily recrystallized steel strip and a forsterite-coated grain-oriented magnetic steel strip to obtain a steel strip coil and thermally etching the coil in finish annealing while controlling the orientation of the secondary recrystallization. CONSTITUTION:A hot-rolled silicon steel strip contg., by weight, 2.0-4.8% Si, 0.008-0.05% acid-soluble Al, <=0.010% N and the balance Fe is annealed, if necessary, cold-rolled once or >=2-times including process annealing to obtain a specified thickness and primarily recrystallization-annealed. The primarily recrystallized steel strip 7 is combined with a forsterite-coated steel strip 6 and wound to obtain a steel strip coil 1 wherein the strips 6 and 7 are alternately placed. The coil is mounted on a reel at the low-temp. part 3 of a finish- annealing furnace 5, wound on a reel 2 at the high-temp. part 4 kept at 920-1150 deg.C so that the steel strip is heated at the rate of 250 deg.C/h, held for >=5hr in a neutral or reducing atmosphere and secondarily recrystallized. |
