A grain-oriented electrical steel sheet according to the present invention includes a silicon steel sheet as a base steel sheet, and when an average value of amplitudes in a wavelength range of 20 to 100 μm among wavelength components obtained by performing Fourier analysis on a measured cross-sectional curve parallel to a sheet width direction of the silicon steel sheet is set as ave-AMP.sub.C100, ave-AMP.sub.C100 is 0.0001 to 0.050 μm.

Methods for processing an iron cobalt alloy, along with components formed therefrom, are provided. The method may include: pre-annealing a sheet of an iron cobalt alloy at a pre-anneal temperature (e.g., about 770° C. to about 805° C.); thereafter, cutting a component from the sheet; thereafter, heat-treat annealing the component at a treatment temperature (e.g., about 845° C. to about 870° C.) for a treatment period (e.g., about 1 minute to about 10 minutes); and thereafter, exposing the component to oxygen at an oxidizing temperature to form an insulation layer on a surface of the component.

A method of producing a non-oriented electrical steel sheet by hot rolling and cold rolling a steel slab comprising by mass % C: not more than 0.0050%, Si: 2-7%, Mn: 0.05-2.0%, P: not more than 0.2%, S: not more than 0.005%, Al: not more than 3%, N: not more than 0.005%, Ti: not more than 0.003%, Nb: not more than 0.005% and V: not more than 0.005% and then subjecting to a finish annealing and a stress-relief annealing, conditions of the finish annealing and stress-relief annealing are adjusted so that a yield stress of the steel sheet after the finish annealing is not less than 400 MPa and a ratio of a magnetic flux density B.sub.50S of the steel sheet after the stress-relief annealing to a magnetic flux density B.sub.50H after the finish annealing is not less than 0.99.

This non-oriented electrical steel sheet includes a base metal having a predetermined chemical composition satisfying the expression [Si+0.5×Mn≥4.3], and an average grain size of the base metal is more than 40 μm and 120 μm or less.

Provided are a non-oriented electrical steel sheet with which it is possible to improve steel sheet transferability even when punching is performed successively at high speed, and a method of manufacturing a stacked core using the same. The non-oriented electrical steel sheet contains, by mass percent, Si: 2.0 to 5.0%, Mn: 0.4 to 5.0%, Al≤3.0%, C: 0.0008 to 0.0100%, N≤0.0030%, S≤0.0030%, and Ti≤0.0060%, wherein the product of the contents of Mn and C is 0.004 to 0.05 mass %.sup.2, the yield strength in rolling direction is more than or equal to 600 MPa, and the Young's modulus is more than or equal to 200 GPa. In the method of manufacturing a stacked core, when manufacturing a stacked core using a progressive die, the steel sheet transfer speed V (m/s) satisfies expression (1). V: V.sub.MIN to V.sub.MAX (1) V.sub.MAX=( 1/25)√(t.sup.2×E×YS) (2) V.sub.MIN=( 1/25)√(t.sup.2×120000) (3) t: Steel sheet thickness (mm), E: Young's ratio (GPa), YS: Yield strength (MPa)

The soft magnetic alloy of the present disclosure is represented by a composition formula of Fe.sub.aSi.sub.bB.sub.cCu.sub.dM.sub.e where M is at least one type of element selected from a group consisting of Nb, Mo, V, Zr, Hf, and W, and the formula satisfies 82.5≤a≤86, 0.3≤b≤3, 12.5≤c≤15.0, 0.05≤d≤0.9, and 0≤e<0.4 in at %. The soft magnetic alloy includes a structure that has a crystal grain with a grain diameter of 60 nm or less in an amorphous phase.

A high-magnetic-induction low-iron-loss non-oriented silicon steel sheet and a manufacturing method therefor. The chemical composition by mass percentages is: C≤0.005%, Si: 0.1%˜1.6%, Mn: 0.1%˜0.5%, P≤0.2%, S≤0.004%, Al≤0.003%, N≤0.005%, Nb≤0.004%, V≤0.004% and Ti≤0.003%, with the balance being Fe and inevitable impurities; and at the same time satisfies: 120≤[Mn]/[S]≤160, and [Nb]/93+[V]/51+[Ti]/48+[Al]/27≤[C]/12+[N]/14. After casting, the cooling rate in a cool-down process of casting slab is controlled, and a temperature controlling method is used to adjust the charging temperature of casting slab.

Methods for producing non-oriented electrical steel sheets comprising steps including hot rolling a slab having a chemical composition comprising C: not more than 0.01 mass %, Si: not more than 6 mass %, Mn: 0.05-3 mass %, P: not more than 0.2 mass %, Al: not more than 2 mass %, N: not more than 0.005 mass %, S: not more than 0.01 mass %, Ga: not more than 0.0005 mass %, and the remainder being Fe and inevitable impurities, pickling without conducting hot band annealing or after conducting hot band annealing or self-annealing, subjecting to one or more cold rollings including an intermediate annealing therebetween and a finish annealing, and forming an insulation coating, an average heating rate from 500 to 800° C. in the heating process of the finish annealing is not less than 50° C./s, whereby a non-oriented electrical steel sheet having excellent magnetic properties is obtained even if hot band annealing is omitted.

A grain oriented electrical steel sheet includes: by mass %, 0.010% or less of C; 2.50 to 4.00% of Si; 0.010% or less of acid soluble Al; 0.012% or less of N; 1.00% or less of Mn; 0.020% or less of S; and a balance consisting of Fe and impurities, and has a tension-insulation coating at steel sheet surface and a SiO.sub.2 intermediate oxide film layer with an average thickness of 1.0 nm to 1.0 μm at an interface between the tension-insulation coating and the steel sheet surface. In the grain oriented electrical steel, when a surface of the intermediate oxide film layer is analyzed by an infrared reflection spectroscopy, a peak intensity I.sub.A at 1250 cm.sup.−1 and a peak intensity I.sub.B at 1200 cm.sup.−1 satisfy I.sub.B/I.sub.A≥0.010.

The present invention provides a method for cutting an electromagnetic steel with a fiber laser, a method for producing an electromagnetic steel component wherein deterioration of magnetic properties is minimized and a rust-preventive effect is endowed, and a method for fabricating a core from the electromagnetic steel component cut by the fiber laser wherein an occurrence of varnish pool is suppressed. According to the present invention, an electromagnetic steel component is obtained by irradiating and cutting the electromagnetic steel sheet with a fiber laser while spraying an assist gas comprising an oxygen concentration of at least 50 volume percent, wherein the electromagnetic steel component is formed with an oxide film for preventing the occurrence of rust and minimizing degradation of magnetic properties to be caused by the heat of the fiber laser. The degraded magnetic properties of the electromagnetic steel component can be restored by the subsequent annealing treatment.