There is provided a water-based alkaline composition for forming an insulating layer of an annealing separator on a soft magnetic alloy, this composition comprising ceramic particles with a particle size of less than 0.5pm and at least one polymer dispersion as a binding agent, the polymer dispersion comprising one or more mixed polymerisates from the group made up of acrylate polymers, methacrylate polymers, polyvinyl acetate, polystyrene, polyurethane, polyvinyl alcohol, hydroxylated cellulose ether, polyvinyl pyrrolidone, and polyvinyl butyral, and having a pH value of between 8 and 12, preferably between 9 and 11.

This electrical steel sheet contains, as a chemical composition, by mass %, C: 0.0035% or less, Si: 2.00% to 3.50%, Mn: 2.00% to 5.00%, P: 0.050% or less, S: 0.0070% or less, Al: 0.15% or less, N: 0.0030% or less, Ni: 0% to 1.00%, Cu: 0% to 0.10%, and a remainder: Fe and impurities, in which an X-ray random intensity ratio in a {100} <011> crystal orientation on a sheet surface is 15.0 to 50.0, and magnetic flux densities in 0°, 22.5°, and 45° directions from a rolling direction each satisfy [1.005×(B.sub.50 (0°)+B.sub.50 (45°))/2≥B.sub.50 (22.5°)].

An apparatus and a method for rapidly heating cold-rolled strip steel (10). The apparatus for rapidly heating cold-rolled strip steel (10) comprises a heating zone, a soaking zone, and a cooling zone, and the heating zone is sequentially divided into a first heating section (1), a second heating section (2), a third heating section (3), and a fourth heating section (4) along a moving direction of the strip steel (10) to be heated, the first heating section (1) and the fourth heating section (4) being radiant heating sections, and the second heating section (2) and the third heating section (3) being inductive heating sections. The method for rapidly heating cold-rolled strip steel (10) uses the apparatus for rapidly heating cold-rolled strip steel (10) to heat the strip steel (10).

Proposed is a non-oriented electrical steel sheet being low in iron loss and excellent in tensile strength and fatigue strength, which has a chemical composition comprising C: not more than 0.005 mass %, Si: 3 to 5 mass %, Mn: not more than 5 mass %, P: not more than 0.1 mass %, S: not more than 0.01 mass %, Al: not more than 3 mass %, N: not more than 0.005 mass %, Zn: 0.0005 mass % to 0.003 mass %, and the remainder being Fe and inevitable impurities, an average crystal grain size being not more than 40 μm, the number of the inclusions having a diameter of not less than 5 μm being not more than 5/mm.sup.2, a tensile strength being not less than 600 MPa, and the fatigue strength being not less than 450 MPa.

Provided is a method of manufacturing a grain-oriented electrical steel sheet with which a grain-oriented electrical steel sheet with excellent magnetic properties and little variation in iron loss in the longitudinal direction of a coil can be stably manufactured. The method includes subjecting a steel slab to hot-rolling and optionally to annealing, then performing cold rolling once or twice or more to obtain a cold-rolled sheet with a final sheet thickness, and then subjecting the cold-rolled sheet to decarburization annealing and then secondary recrystallization annealing, where immediately before final cold rolling, a steel sheet is heated at a heating rate of 100° C./s or more to a heating temperature of 100° C. or higher and 350° C. or lower, and a time from when the steel sheet reaches the heating temperature to when it is bitten in a first pass of final cold rolling is set to within 5 seconds.

A grain-oriented electrical steel sheet includes: a steel sheet and optionally an insulation coating formed on the steel sheet, in which, in a case where a heat treatment of performing retention at 800° C. for 2 hours is performed, regarding a time-magnetostriction waveform (t−λ waveform) when magnetized to 1.7 T, a peak value of a difference waveform obtained by subtracting the time-magnetostriction waveform after the heat treatment from the time-magnetostriction waveform before the heat treatment is 0.01×10.sup.−6 or more and 0.20×10.sup.−6 or less, and a difference obtained by subtracting an iron, loss before the heat treatment from an iron loss after the heat treatment is 0.03 W/kg or more and 0.17 W/kg or less.

There is provided a method for manufacturing a soft magnetic member where a coating formed of an α-Fe.sub.2O.sub.3 single phase having a high electrical resistivity is formed on a soft magnetic alloy substrate. A soft magnetic alloy substrate is heated in an atmosphere containing water vapor and inert gas to form a coating on the soft magnetic alloy substrate. The atmosphere has an oxygen partial pressure in a range of 0 to 1.5 kPa. A soft magnetic member including the soft magnetic alloy substrate and the coating formed on its surface can be obtained.

Provided is a method for manufacturing a grain-oriented electrical steel sheet to reduce iron loss by controlling the magnetic domain structure, in which the iron loss reduction effect can be maintained even when stress relief annealing is applied, and the magnetic flux density does not decrease after the magnetic domain control treatment. In the manufacturing method, on a surface of the grain oriented electrical steel sheet, a laser beam with a ring-shaped intensity distribution in which the intensity in a periphery is lower than that in a center is irradiated in a linear manner in a direction intersecting a rolling direction of the steel sheet.

A method for processing a siliceous, hot-rolled steel sheet for producing an electric steel strip, wherein the steel sheet contains more than 1.5% parts by weight of silicon. The method may include conducting a surface treatment in a device for removing oxide layers from a surface of the steel sheet to produce a cleaned steel sheet, and conducting a heat treatment of the cleaned steel sheet after the surface treatment in a hot-rolled strip annealing plant in an inert gas atmosphere. The surface treatment for removing the oxide layers may be carried out mechanically, without chemical descaling. The heat treatment of the cleaned steel sheet is carried out subsequent to the surface treatment.

A nanocrystalline alloy ribbon has an alloy composition represented by Fe.sub.balCu.sub.xB.sub.ySi.sub.zA.sub.aX.sub.b where 0.6≤x<1.2, 10≤y≤20, 0<z≥10, 10(y+z)24, 0≤a≤10, O≤b≤5, with the balance being Fe and incidental impurities, where A is an optional inclusion of at least one element selected from Ni, Mn, Co, V, Cr, Ti, Zr, Nb, Mo, Hf, Ta and W, and X is an optional inclusion of at least one element selected from Re, Y, Zn, As, In, Sn, and rare earth elements, all numbers being in atomic percent. The ribbon has a local structure having nanocrystals with average particle sizes of less than 40 nm dispersed in an amorphous matrix, the nanocrystals occupying more than 30 volume percent of the ribbon and has a radius of ribbon curvature of at least 200 mm.