Production manner of the directivity electromagnetic steel sheet which is superior in coat property and annealing separable medicine null for the directivity electromagnetic steel sheet

摘要

PROBLEM TO BE SOLVED: To stably obtain a grain oriented electrical steel sheet having excellent film properties, which has satisfactory film adhesion, and is free from the change of color tones and the generation of a spot defect.;SOLUTION: In the method for producing a grain oriented electrical steel sheet composed of a series of stages where a steel slab comprising, by mass, 2 to 4% Si is subjected to hot rolling and hot rolled sheet annealing, is thereafter subjected to final cold rolling, and is next subjected to primary recrystallization annealing, subsequently, the surface of the steel sheet is coated with a separation agent for annealing having MgO as a primary component, and then, final finish annealing is performed, the physical properties of the separation agent for annealing are evaluated by a surface fluorescent X-ray Mg intensity ratio A in the case a steel sheet coated with the separation agent for annealing and a steel sheet not coated therewith are subjected to final finish annealing at the intervals of 5 mm [A=I(noncoating)/I(coating)], and the separation agent for annealing in which the value satisfies the range of 0.5≤A≤1.5 is used.;COPYRIGHT: (C)2007,JPO&INPIT