| 摘要 |
PURPOSE:To produce a unidirectionaly oriented electrical steel plate having high magnetic flux density and uniform magnetic characteristics in the longitudinal direction, by eliminating the nonuniformity in heating conditions for slabs and magnetic characteristics in the hot rolling stage of silicon steel plates by controlling the cooling conditions after annealing of hot rolled plates variably in the longitudinal direction of coils. CONSTITUTION:A slab of silicon steel contg. <4.0% Si, <0.085% C, 0.010-0.065% acid soluble Al, and 0.003-0.0100% total N is hot-rolled with rough hot rolling mills, and in succession, the slab is hot-rolled to a plate with continuous hot finishing mills. The hot-rolled plate is annealed continuously at high temps. of 950-1,200 deg.C and is then cooled quickly. This cooling is accomplished by cooling the hot-rolled heat part where the hot finish rolling temp. in the longitudinal direction of the coil is high quickly and cooling the hot rolled tail part where the hot rolling temp. is low slowly. The steel is thereafter rolled to a final product thickness by one time of cold rolling, and is subjected to continuous decarburizing and annealing in a wet hydrogen atmosphere followed by final annealing at >=800 deg.C. The unidirectionally oriented electrical steel plate having high magnetic flux density and uniform magnetic characteristics in the longitudinal direction is obtained. |
