Master sheet for oriented electric steel sheet, method of manufacturing directional silicon steel sheet, material for directing electromagnetic steel sheet, and method of manufacturing directional electromagnetic steel sheet

摘要

In the original plate for directional electromagnetic steel plate of the present invention, the amount of oxygen x per surface of the original plate and the peak of SiO2 on the surface of the original plate obtained by reflection infrared spectroscopic analysis (ΔR / R0 @ 1250 cm-1). The value y of is satisfied with y ≧ 1500x2.5 and y ≧ 0.24. In the method for producing the original plate for a directional electromagnetic steel plate of the present invention, the amount of surface oxygen per one side of the finish-annealed directional silicon steel plate is 0.01 g / m2 or more and 0.05 g / m2 or less, or 0.05 g / m2 or more and 0. The step of adjusting to 10 g / m2 or less and the oxidation potential indicated by the ratio of water vapor pressure to hydrogen pressure PH2O / PH2 is 0.0081 when the surface oxygen amount is more than 0.01 g / m2 and 0.05 g / m2 or less. In the following atmosphere, when the surface oxygen amount is more than 0.05 g / m2 and 0.10 g / m2 or less, thermal oxidation annealing is performed in an atmosphere of 0.005 or less at a soaking temperature of 1000 ° C. or less, and the directionality is described. A step of forming an external oxide layer on the surface of a silicon steel plate is provided.