PURPOSE: To improve the film characteristics and magnetic characteristics of a grain oriented electrical steel sheet by disposing plural pieces of polishing devices for forming fine ruggedness to a zigzag shape in specific directions on the surface of the steel sheet and rotating revolving shafts of the polishing devices contiguous to each other in the transverse direction of the steel sheet oppositely from each other.
CONSTITUTION: Plural pieces of the polishing devices 2 are so disposed that the polishing directions are orthogonal with the passing direction A of the grain oriented steel sheet 1 or within ±60° with the direction orthogonal therewith to form the fine ruggedness (about 1W15μ depth) on the surface of the steel sheet 1. The polishing devices 2 are spaced from each other and are provided zigzag at this time and are so disposed that the rotating directions of the revolving shafts of the devices 2-1, 2-2 contiguous to each other in the transverse direction of the steel sheet are diametrically opposed from each other. The ruggedness is thereby industrially stably formed on the surface of the steel sheet 1 without generating pass troubles, etc., and the film characteristics and iron loss characteristics thereof are improved.
TAKADA TOSHIHIKO
TANAKA OSAMU
HOTANI SETSUO
HOTANI KK