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AssigneeHitachi Metals, Ltd.
InventorsYoshihito Yoshizawa, Motoki Ohta, Naoki Ito
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A rapidly quenched Fe-based soft-magnetic alloy ribbon having wave-like undulations on a free surface, the wave-like undulations having transverse troughs arranged at substantially constant intervals in a longitudinal direction, and the troughs having an average amplitude D of 20 mm or less, is produced by a method comprising (a) keeping a transverse temperature distribution in a melt nozzle within ±15° C. to have as small a temperature distribution as possible in a melt paddle of the alloy, and (b) forming numerous fine linear scratches on a cooling roll surface by a wire brush, thereby providing a ground surface of the cooling roll with an arithmetical mean (average) roughness Ra of 0.1-1 μm and a maximum roughness depth Rmax of 0.5-10 μm.
A method for producing a quenched Fe-based amorphous alloy ribbon having wave-like undulations on a free surface by a single roll method, said wave-like undulations having transverse troughs arranged at longitudinal intervals, and said troughs having an average amplitude D of 20 mm or less, the method comprising the steps of (a) keeping a transverse temperature distribution in a melt nozzle within ±15° C. by using a heating nozzle having a slit-shaped opening for blowing a heating gas onto the melt nozzle, the length of the slit-shaped opening of the heating nozzle being 1.2-2 times the horizontal length of a slit-shaped orifice of the melt nozzle, the temperature of a heating gas ejected from the heating nozzle being 1000-1400° C.;
Dependencies are inferred from the claim text.