A grain-oriented electrical steel sheet has a steel sheet and an insulating coating which is formed on a surface of the steel sheet. In the insulating coating, a metal phosphate and a colloidal silica are contained, the colloidal silica is contained in an amount of 20 to 150 parts by mass with respect to 100 parts by mass of the metal phosphate, one or more kinds of fine particles selected from the group consisting of silicon carbide, silicon nitride, aluminum nitride, boron nitride, sialon, and cordierite are further contained in an amount of 0.5 to 7 parts by mass with respect to 100 parts by mass of the metal phosphate, an average particle size of the fine particles is 0.3 to 7.0 μm, crystallized ratio of the metal phosphate is 2% to 40%, and chromium is not contained.

The present disclosure provides a method that ensures easily manufacturing an alloy ribbon piece having excellent soft magnetic properties. The method is a method for manufacturing an alloy ribbon piece obtained by crystallizing an amorphous alloy ribbon piece and including: increasing a temperature of the amorphous alloy ribbon piece to a crystallization starting temperature; and increasing the temperature of the amorphous alloy ribbon piece from the crystallization starting temperature to a crystallization process termination temperature equal to or less than a crystallization completion temperature. A temperature increase rate of the amorphous alloy ribbon piece in the increasing of the temperature of the amorphous alloy ribbon piece from the crystallization starting temperature to the crystallization process termination temperature satisfies ΔQ.sub.self≤ΔQ.sub.out+mcΔT where a self-heating amount, a heat discharge amount, a mass, a specific heat, and a temperature increase width of the amorphous alloy ribbon piece per unit time is ΔQ.sub.self, ΔQ.sub.out, m, c, and ΔT, respectively.

The present disclosure provides a method that ensures easily manufacturing an alloy ribbon piece having excellent soft magnetic properties. The method is a method for manufacturing an alloy ribbon piece obtained by crystallizing an amorphous alloy ribbon piece and including: increasing a temperature of the amorphous alloy ribbon piece to a crystallization starting temperature; and increasing the temperature of the amorphous alloy ribbon piece from the crystallization starting temperature to a crystallization process termination temperature equal to or less than a crystallization completion temperature. A temperature increase rate of the amorphous alloy ribbon piece in the increasing of the temperature of the amorphous alloy ribbon piece from the crystallization starting temperature to the crystallization process termination temperature satisfies ΔQ.sub.self≤ΔQ.sub.out+mcΔT where a self-heating amount, a heat discharge amount, a mass, a specific heat, and a temperature increase width of the amorphous alloy ribbon piece per unit time is ΔQ.sub.self, ΔQ.sub.out, m, c, and ΔT, respectively.

Disclosed is a high-permeability ferrite-based stainless steel. According to an embodiment, the disclosed high-permeability ferrite-based stainless steel includes, in percent by weight (wt %), 0.0005 to 0.02% of C, 0.005 to 0.02% of N, 0.2 to 2.0% of Si, 10.0 to 25.0% of Cr, 0.05 to 0.5% of Nb, and the remainder of Fe and other inevitable impurities, wherein a Nb/(C+N) value satisfies a range of 5 to 20 and a <001>//RD texture fraction is 5% or more.

Disclosed is a high-permeability ferrite-based stainless steel. According to an embodiment, the disclosed high-permeability ferrite-based stainless steel includes, in percent by weight (wt %), 0.0005 to 0.02% of C, 0.005 to 0.02% of N, 0.2 to 2.0% of Si, 10.0 to 25.0% of Cr, 0.05 to 0.5% of Nb, and the remainder of Fe and other inevitable impurities, wherein a Nb/(C+N) value satisfies a range of 5 to 20 and a <001>//RD texture fraction is 5% or more.

The present invention relates to a grain-oriented electrical steel sheet including 2.0 to 6.0 wt % of Si, 0.01 wt % or less (excluding 0 wt %) of C, 0.01 wt % or less (excluding 0 wt %) of N, and 0.005 to 0.1 wt % of Co, and including a balance of Fe and other inevitable impurities.

The present invention relates to a grain-oriented electrical steel sheet including 2.0 to 6.0 wt % of Si, 0.01 wt % or less (excluding 0 wt %) of C, 0.01 wt % or less (excluding 0 wt %) of N, and 0.005 to 0.1 wt % of Co, and including a balance of Fe and other inevitable impurities.

Disclosed are a non-oriented electrical steel sheet and a manufacturing method therefore, the sheet ensuring excellent magnetic characteristics by having increased texture intensity of surface (100) through strict control of the content ratio of Si, Al and the like and through final annealing heat treatment in an inert gas atmosphere.

Disclosed are a non-oriented electrical steel sheet and a manufacturing method therefore, the sheet ensuring excellent magnetic characteristics by having increased texture intensity of surface (100) through strict control of the content ratio of Si, Al and the like and through final annealing heat treatment in an inert gas atmosphere.

A method for manufacturing a non-oriented electrical steel sheet includes a step of performing hot rolling on a steel material having a predetermined chemical composition, a step of performing first cold rolling, a step of performing process annealing, a step of performing second cold rolling, and a step of performing any one or both of final annealing and stress relief annealing. A final pass of finish rolling is performed in a temperature range equal to or higher than an Ar1 temperature, the steel sheet is held for 2 hours or less in a temperature range lower than an Ac1 temperature in the final annealing, and the steel sheet is held for 1200 sec or more in a temperature range equal to or higher than 600° C. and lower than the Ac1 temperature in the stress relief annealing.