Provided is a method for manufacturing a high silicon steel sheet having excellent producibility and magnetic properties. The method includes: casting a molten metal as a strip having a thickness of 5 mm or less, the molten metal comprising, by weight %, C: 0.05% or less (excluding 0%), N: 0.05% or less (excluding 0%), Si: 4% to 7%, Al: 0.5% to 3%, Si+Al: 4.5% to 8%, and the balance of Fe and inevitable impurities; hot-rolling the cast strip at a temperature of 800 C. or higher; annealing the hot-rolled strip at a temperature within a range of 900 C. to 1200 C.; cooling the annealed strip; warm-rolling the quenched strip at a temperature within a range of 300 C. to 700 C.; and finally annealing the warm-rolled strip at a temperature within a range of 800 C. to 1200 C.

A metal strip contains a metal magnetic material as a main component, and is formed such that a surface roughness of one main surface is higher than a surface roughness of an other main surface. The other main surface is formed in a smooth surface having a high surface smoothness, and the one main surface is subjected to surface treatment such that a striped pattern composed of a recessed portion and a protruding portion is continuously formed. After a continuous strip is made by a single-roll liquid quenching method, the striped pattern is formed by subjecting one main surface of the continuous strip to surface treatment. A magnetic core is obtained by winding the metal strip in an annular shape, and a coil component, such as a common mode choke coil, is obtained by using the magnetic core. Thus, the metal strip has sufficient toughness and good mechanical strength.

The preparation method includes steps of (1) melting steel according to in weight percentage 0.001-0.003% of C, 5.0-6.6% of Si, 0.2-0.3% of Mn, 0.05-0.12% of Al, 0.01-0.04% of V, 0.03-0.06% of Nb, 0.02-0.03% of S, 0.009-0.020% of N, O which is less than or equal to 0.0020%, and the balance being Fe and unavoidable impurities; (2) forming cast strips after a thin-strip casting course; (3) hot-rolling the cast strips under inert atmosphere conditions; (4) cooling the hot-rolled cast strips to 550-600 DEG C., coiling and performing low-temperature hot rolling/warm rolling on the coiled cast strips under a nitrogen atmosphere condition; (5) removing oxidized scales though pickling, performing cold rolling multiple times; (6) performing recrystallization annealing, coating with an MgO layer, and coiling; (7) performing purification annealing under hydrogen circulation conditions; and (8) removing oxidized scales, coating with an insulating layer, performing flat stretch annealing, and air-cooled coiling.

An FeNi alloy composition comprising an L1.sub.0-type FeNi ordered phase is provided, which satisfies at least one of the conditions that the sum of the content of Fe and the content of Ni is 90 at. % or less and that the FeNi alloy composition contains Si, and preferably satisfies at least one of the conditions that the ratio of the content of Fe to the content of Ni is 0.3 or more and 5 or less and that the sum of the content of Fe and the content of Ni is 65 at. % or more.

The present disclosure has as its object the provision of non-oriented electrical steel sheet excellent in magnetic properties which is free from any drop in magnetic flux density even after stress relief annealing and a method for manufacturing the same. Non-oriented electrical steel sheet having a chemical composition containing C: 0.0030 mass % or less, Si: 2.0 mass % or more and 4.0 mass % or less, Al: 0.010 mass % or more and 3.0 mass % or less, Mn: 0.10 mass % or more and 2.4% mass or less, P: 0.0050 mass % or more and 0.20 mass % or less, S: 0.0030 mass % or less, and one or more elements selected from the group comprising Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: total 0.00050 mass % or more and having a balance of Fe and unavoidable impurities, where, when designating a mass % of Si as [Si], a mass % of Al as [Al], and a mass % of Mn as [Mn], a parameter Q shown by the following formula (1) is 2.0 or more, a random intensity ratio of the {100} orientation is 2.4 or more, and an average grain size is 30 m or less:
Q=[Si]+2[Al][Mn](1).

An electrical steel strip that is less than 3 mm in thickness and is made from a molten electrical steel melt having a superheat temperature of at least 30 C. above the liquidus temperature Tliquidus of the melt comprising: by weight, up to 0.015% carbon, between 1.0% and 2.0% manganese, between 2.70% and 3.80% silicon, silicon killed containing less than 0.01% aluminum, and optionally any one or more of up Cu, Cr, Ni, Mo, Ti, Nb, V, Sb, and Sn; and the remainder iron, impurities and inclusions, is disclosed. A twin roll cast and hot rolled electrical steel strip is disclosed. A subsequently cold rolled and annealed electrical steel strip is also disclosed. Methods of producing these products via a twin roll strip caster are also disclosed.

The method includes slab-heating a steel slab to a temperature of higher than a -phase precipitation temperature and 1380 C. or lower, subjecting the steel slab to rough rolling including at least two passes of rolling at a predetermined temperature with an introduced sheet thickness true strain .sub.t of 0.50 or more and to finish rolling with a rolling finish temperature of 900 C. or higher to obtain a hot-rolled sheet, cooling the hot-rolled sheet for 1 second or longer at a cooling rate of 70 C./s or higher within 2 seconds after finish rolling, coiling the sheet at a coiling temperature of 600 C. or lower, performing hot-rolled sheet annealing for soaking at a predetermined soaking temperature, and then performing cold rolling, primary recrystallization annealing, and secondary recrystallization annealing.