PURPOSE: To obtain a silicon steel sheet excellent in electromagnetic properties by growting columnar crystalline grains in a direction perpendicular to the sheet face of a steel sheet having a specified compsn. mixed with solid soln. strengthening elements such as Si and Al and contg. C and N and intensely orienting the <100> axis.
CONSTITUTION: An Ni silicon steel sheet constituted of, by weight, ≤0.01% C+N, 2 to 5% Si+Al and >1 to 8% Ni is used. This steel sheet is decarburized; after that the area from the surface layer part to 5 to 250μ is decarburized in a bright state at a temp. in which the α-ferritic single phase is formed; and successively, the whole of the steel sheet is subjected to decarburization annealing to ≤0.01% C+N. In this way, the high tensile strength silicon steel sheet having columnar crystalline grains grown from the surface to the inside in a direction perpendicular to the sheet face, in which the <100> axis is integrated at a high density in the above direction and excellent in magnetic properties can be obtd.
KANEKO TERUO
YASHIKI HIROYOSHI
