Abstract: An apparatus for applying a powder of anti-sticking agent on a coil of oriented electrical steel strip formed on a coiler comprises a movable assembly moving closer to and away from the coiler, a stationary hood attached to the movable assembly and having slit-like suction ports provided along the walls thereof, one end of the suction ports opening toward the coiler, a duct-collecting duct connected to the slit-like suction ports of the stationary hood, movable hoods provided on the stationary hood to vertically open at the top and bottom of the open end of the stationary hood, and a group of electrostatic powder spray guns directed toward the coiler in the stationary hood in which they are disposed. The movable assembly recedes and the movable hoods open as the diameter of the coil increases so that a given space is always maintained between the surface of the coiled strip and the movable hoods.

Abstract: A grain-oriented electrical steel sheet having a low watt loss after stress relief annealing is proposed. The steel sheet, which is final texture annealed, and to which tension is imparted, has a number of recessed parts on the surface thereof forming indentations into the steel sheet body having a depth in the range of from 0.01 to 0.1 mm. The recessed parts are filled with a composition having a coefficient of thermal expansion smaller than that of the steel sheet body. From the recessed parts and the composition the magnetic domains are subdivided.

Abstract: An annealing separator used in a finishing annealing step for producing a grain-oriented electrical steel sheet usually contains magnesia. The present invention is characterized by including, based on 100 parts by weight of magnesia, from 0.2 to 20 parts by weight of ferromanganese nitride or manganese nitride which consists of a composition (Mn.sub.1-x Fe.sub.x)N.sub.y having x and y values corresponding to A, B, C, and D and falling within a region surrounded by A, B, C, and D shown in the appended FIG. 1.The annealing separator according to the present invention is effective for stabilizing secondary recrystallization and improving the properties of a forsterite film.

Abstract: The insulating film comprised mainly of phosphate or chromate is improved in its insulation property required for the laminated core e.g., a transformer, the blanking property required for manufacturing the core sections from the electrical steel sheet, and the lamination weldability. The organic resin particles used for controlling the surface roughness of the film are preliminarily treated with a dispersion improver, and then added to the emulsion resin, which is then mixed with the phosphate or chromate.

Abstract: A water repellent, for example an organic silicon compound, is added to an annealing separator which is applied electrostatically to the surface of a grain oriented magnetic steel sheet, or a glass-like film forming undercoating formed on the sheet surface.

Abstract: A process of providing electromagnetic steel strips or sheet with excellent magnetic properties. The process comprises the steps of:irradiating with a laser-beam the surface of an electromagnetic steel sheet which has been finally annealed, thereby locally forming marks of the laser-beam irradiation on the surface of the steel, and;subsequently, subjecting the steel sheet to the formation of an insulating film on the sheet surface at a temperature of the sheet not exceeding 600.degree. C.

Abstract: A method for providing an annealed electrical steel sheet which is highly resistant to sticking to another sheet superimposed thereon at a high temperature, is provided by forming, on the surrace of the sheet, an anti-sticking layer consisting essentially of a colloidal inorganic substance, for example, colloidal silica, alumina and lithium silicate and, optionally, a film-forming organic resinous substance, for example, an acrylic polymer, vinyl acetate polymer and polyester resins.

Abstract: Method for producing a grain-oriented electrical steel sheet or strip having uniform magnetic and film properties said method comprising applying an annealing separator containing one or more metal nitrides, such as, chromium nitride, titanium nitride and vanadium nitride to the steel sheet and annealing the steel sheet at a temperature not lower than 1,100.degree.C.