A chemical composition of a base metal of a non-oriented electrical steel sheet contains, by mass %, C: 0.0050% or less, Si: 3.8% to 5.0%, Mn: exceeding 0.2% and less than 2.0%, P: 0.030% or less, S: 0.0030% or less, Al: 0.005% or more and less than 0.050%, N: 0.0005% to 0.0030%, Ti: less than 0.0050%, Nb: less than 0.0050%, Zr: less than 0.0050%, V: less than 0.0050%, Cu: less than 0.20%, Ni: less than 0.50%, Sn: 0% to 0.10%, Sb: 0% to 0.10%, a remainder: Fe and impurities. [Si+0.5×Mn≥4.3] is satisfied and the average grain size of the base metal is in a range of 10 to 80 μm.

A non-oriented electrical steel sheet has a predetermined chemical composition. The chemical composition satisfies (2×[Mn]+2.5×[Ni]+[Cu])−([Si]+2×[sol.Al]+4×[P])≥1.50%. In a case where Ahkl-uvw represents the area ratio of crystal grains in an {hkl}<uvw> orientation to the entire visual field when a plane at a depth of ½ of a sheet thickness from a surface parallel to a rolled surface is measured by SEM-EBSD, A411-011 is 15.0% or more, and the average grain size is 50 μm to 150 μm.

Provided is a non-oriented electrical steel sheet that contains substantially no Al and contains large amounts of Si and Mn and has low iron loss, comprising a chemical composition containing C: 0.0050% or less, Si: 2.0% or more and 6.0% or less, Mn: 1.0% or more and 3.0% or less, P: 0.20% or less, S: 0.0050% or less, N: 0.0050% or less, Al: 0.0050% or less, and one or more selected from B: 0.0001% or more and 0.0050% or less, Nb: 0.0001% or more and 0.0050% or less, and V: 0.0005% or more and 0.0500% or less, with a balance consisting of Fe and inevitable impurities, wherein a number density of Si—Mn nitrides with an average diameter of 50 nm or more and 500 nm or less is 1 or less per μm.sup.3.

A non-oriented electrical steel sheet including a base metal that has a chemical composition including, in mass%, C: 0.0010 to 0.0040%, Si: 4.0 to 5.0%, Mn: 0.20% or less Al: 0.010% or more and less than 0.050%, P: 0.030% or less, S: 0.0030% or less, N: 0.0005 to 0.0030%, O: 0.0100 to 0.0400%, Ca: less than 0.0010%, Ti: less than 0.0050%, Nb: less than 0.0050%, Zr: less than 0.0050%, V: less than 0.0050%, Cu: less than 0.20%, Ni: less than 0.50%, Sn: 0 to 0.05%, Sb: 0 to 0.05%, and a balance: Fe and impurities, in which the base metal has an O content of less than 0.0050% in a region excluding a portion from a surface of the base metal to a position of 10 .Math.m in a depth direction of the base metal.

A non-oriented electrical steel sheet including a base metal that has a chemical composition including, in mass %, C: 0.0010 to 0.0040%, Si: 3.5 to 4.9%, Mn: 0.05 to 0.20%, Al: 0.05 to 0.45%, P: 0.030% or less, S: 0.0030% or less, N: 0.0030% or less, O: 0.0100 to 0.0400%, Ca: less than 0.0010%, Ti: less than 0.0050%, Nb: less than 0.0050%, Zr: less than 0.0050%, V: less than 0.0050%, Cu: less than 0.20%, Ni: less than 0.50%, Sn: 0 to 0.05%, Sb: 0 to 0.05%, and a balance: Fe and impurities, and satisfying [4.0≤Si+Al≤5.0], in which the base metal has an O content of less than 0.0050% in a region excluding a portion from a surface of the base metal to a position of 10 μm in a depth direction of the base metal.

Disclosed is a low-cost non-oriented electrical steel plate with an extremely low aluminum content, which plate comprises the following chemical elements in percentage by mass: 0.003% or less of C, 0.1%-1.2% of Si, 0.1%-0.4% of Mn, 0.01%-0.2% of P, 0.003% or less of S, 0.001% or less of Al, 0.003%-0.01% of O, 0.003% or less of N, and 0.005%-0.05% of Sn, with the condition Si.sup.2/P: 0.89-26.04 being satisfied. In addition, further disclosed is a method for manufacturing the non-oriented electrical steel plate. The method comprises steps of: (1) smelting; (2) continuous casting; (3) hot rolling: wherein a hot rolled plate is subjected to soaking and heat preservation by means of residual heat of hot rolled steel coils, rather than being subjected to normalizing treatment or cover furnace annealing after coiling; (4) primary cold rolling; and (5) continuous annealing. In the non-oriented electrical steel plate of the present invention, reasonable chemical ingredients and process designs are used, and the non-oriented electrical steel plate not only has excellent economy, but also has the properties of high magnetic induction and low iron loss.

An annealing separator composition for a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: 100 parts by weight of at least one of a magnesium oxide and a magnesium hydroxide; and 30 to 250 parts by weight of a metal hydroxide including at least one of a nickel hydroxide and a cobalt hydroxide, wherein an average particle diameter of the metal hydroxide is 0.01 to 80 μm.

A method for manufacturing a non-oriented electrical steel sheet according to an exemplary embodiment of the present invention includes performing hot rolling on a slab after heating the slab to manufacture a hot rolled sheet; performing hot rolled sheet annealing on the hot rolled sheet; performing cold rolling on a steel sheet on which the hot rolled sheet annealing is completed to manufacture a cold rolled sheet; and performing cold rolled sheet annealing on the cold rolled sheet in which a difference between a cold rolled sheet annealing temperature in the cold rolled sheet annealing and a hot rolled sheet annealing temperature in the hot rolled sheet annealing is 100° C. or lower.

A non-oriented electrical steel sheet according to an embodiment of the present invention includes Ti at 0.0030 wt % or less (excluding 0 wt %), Nb at 0.0035 wt % or less (excluding 0 wt %), V at 0.0040 wt % or less (excluding 0 wt %), B at 0.0003 wt % to 0.0020 wt %, and the remaining portion including Fe and other inevitably added impurities, wherein a value of ([Ti]+0.8[Nb]+0.5[V])/(10*[B]) may be 0.17 to 7.8.

The present invention relates to a grain oriented electrical steel sheet having excellent core loss and to a method for manufacturing same. The electrical steel sheet according to one aspect of the present invention may have a composition comprising, by weight %, Si: 1.0 to 4.0%, Al: 0.1 to 4.0%, and a rare earth element: 0.0001 to 0.5% by the total content of the whole rare earth element.