A non-oriented electrical steel sheet is produced by performing hot-rolling, hot-band annealing, cold rolling, and finishing annealing with regard to a steel slab containing a certain composition, a soaking temperature in the finishing annealing is set to not lower than 500 C. but not higher than a temperature T determined by the contents of Si, Al, and Mn, a cold-rolled sheet is held at the soaking temperature for a time period of no longer than 60 seconds, and a retention time at a temperature of 500 C. or higher is no longer than 100 seconds, whereby a tensile strength of the steel sheet is 700 to 950 Mpa, and a dislocation density thereof in a central portion of the sheet thickness is 1.210.sup.14 m.sup.2 or more, thus obtaining a non-oriented electrical steel sheet exhibiting a high strength after performing finishing annealing and a low iron loss after performing stress-relief annealing.

An embodiment of the present invention provides a grain-oriented electrical steel sheet, including: a linear groove formed in a direction crossing a rolling direction on one surface or both surfaces of an electrical steel sheet; and a linear thermal shock portion formed in the direction crossing the rolling direction on one surface or both surfaces of the electrical steel sheet. The groove is formed in plural along the rolling direction, a distance D2 between the groove and the thermal shock portion is 0.2 to 0.5 times a distance D1 between the grooves, and a distance D3 between the thermal shock portions is 0.2 to 3.0 times the distance D1 between the grooves.

A new and improved method for producing electrical steel sheet enabling production of electrical steel sheet excellent in magnetic characteristics and coating film adhesion, the method for producing electrical steel sheet containing a process of bringing an electrical steel sheet containing, by mass %, C: more than 0% and 0.10% or less, Si: 2.5% or more and 4.5% or less, Mn: 0.01% or more and 5.0% or less, a total of one or more of S, Se, and Te: more than 0% and 0.050% or less, acid soluble Al: more than 0% and 5.0% or less, N: more than 0% and 0.015% or less, and P: more than 0% and 1.0% or less and having a balance of Fe and impurities into contact with a solution, the solution containing one or more elements from among Cu, Hg, Ag, Pb, Cd, Co, Zn, and Ni, a total of concentrations of the elements being 0.00001% or more and 1.0000% or less.

This non-oriented electrical steel sheet includes a steel sheet, in which the steel sheet contains, as a chemical composition, in % by mass, C: 0.0030% or less, Si: 1.0 to 3.5%, Al: 0.10 to 2.00%, Mn: 0.1 to 2.0%, P: 0.20% or less, S: 0.0030% or less, N: 0.0030% or less, Ti: 0.0030% or less, B: 0.0020% or less, Sn: 0 to 0.200%, Sb: 0 to 0.1000%, and a remainder: Fe and impurities, when a Sn content is represented by [Sn] and an Sb content is represented by [Sb] in % by mass, [Sn]+2[Sb]0.200 is satisfied, and when a sheet width of the steel sheet is represented by W, WH/WL, which is a ratio between a maximum value WH and a minimum value WL of iron loss W10/400 at a W/10 part which is a part at a W/10 position, a W/4 part which is a part at a W/4 position, and a W/2 part which is a part at a W/2 position of the sheet width from an end portion in a width direction, is 1.10 or less.

Provided are a high-strength non-oriented electrical steel sheet having good fatigue resistance suitable for rotor cores and a non-oriented electrical steel sheet having excellent magnetic properties suitable for stator cores. The non-oriented electrical steel sheet has a chemical composition of C: 0.01% or less, Si: 2.0% and more and less than 4.5%, Mn: 0.05% to 5.00%, P: 0.1% or less, S: 0.01% or less, Al: 3.0% or less and N: 0.005% or less, with the balance being Fe and inevitable impurities, where Si+Al is less than 4.5%, For the crystal grains in the steel sheet, the average grain size X.sub.1 is 50 m or less, the standard deviation S.sub.1 of the crystal grain size distribution satisfies the specified formula (1), and the kurtosis K.sub.1 of the crystal grain size distribution is 20.0 or less.

The non-oriented electrical steel sheet includes, as a chemical composition, in terms of mass %, 0.0100% or less of C, 1.50 to 4.00% of Si, 0.0001 to 1.00% of sol.Al, 0.0100% or less of S, 0.0100% or less of N, and 2.50 to 5.00% in total of one or more selected from the group consisting of Mn, Ni, and Cu, wherein, in terms of mass %, when [Mn] is defined as the Mn content, [Ni] is defined as the Ni content, [Cu] is defined as the Cu content, [Si] is defined as the Si content, [sol.Al] is defined as the sol.Al content, and [P] is defined as the P content, (2[Mn]+2.5[Ni]+[Cu])([Si]+2[sol.Al]+4[P])1.50% is satisfied; has A411-011 of 15.0% or more; has a B50D of 1.70 T or more; and has a W10D/400D of 10.4 W/kg or less.

In a non-oriented electrical steel sheet according to the present disclosure, TS is higher than 580 MPa, and when P.sub.120/Fe.sub.700 that is a ratio of a peak-to-peak value P.sub.120 of P around an electron energy of 120 eV to a peak-to-peak value Fe.sub.700 of Fe around an electron energy of 700 eV in Auger differential spectra obtained in a grain boundary region of a fracture surface is defined as [P].sub.GB, and P.sub.120/Fe.sub.700 that is a ratio of a P.sub.120 to Fe.sub.700 in Auger differential spectra obtained in an intragranular region of a fracture surface is defined as [P].sub.IG, the [P].sub.GB and the [P].sub.IG satisfy Formula (1). A difference S between TS and YP is 110 MPa or less, and an average grain size D (m) satisfies Formula (2).

[00001]$\begin{array}{cc}{\left[P\right]}_{GB}{/\left[P\right]}_{\mathrm{IG}}>2.& \left(1\right)\end{array}$$\begin{array}{cc}D100-15{\left[P\right]}_{GB}{/\left[P\right]}_{IG}+1500/\mathrm{TS}& \left(2\right)\end{array}$

Provided is a non-oriented electrical steel sheet having a base metal chemical composition containing, in mass %, C: 0.0040% or less, Si: more than 3.50% and 4.50% or less, Mn: less than 0.60%, Al: 0.30-0.90%, P: 0.030% or less, S: 0.0018% or less, N: 0.0040% or less, Ti: less than 0.0040%, Nb: less than 0.0050%, Zr: less than 0.0050%, V: less than 0.0050%, Cu: less than 0.200%, Ni: less than 0.500%, and a total of one or both of Sn and Sb: 0.005-0.060%, with a balance being Fe and impurities; and satisfying [4.2Si+Al+0.5Mn4.9], wherein the average crystal grain size of the base metal is 10 to 40 m, the integration degree of the {111} <112> orientation is 8.0 or less, and the sheet thickness of the base metal is 0.10 to 0.30 mm.

A non-oriented electrical steel sheet of this embodiment contains, in mass %, Si: 3.1 to 4.5%, and in addition, Ti, Si, Al, Zr, Nb, V, Mo, Cr, C, La, Ce, and N satisfy Formula (1) and Formula (2), a tensile strength TS is higher than 570 MPa, a work hardening amount WH defined by Formula (3) is less than 15 MPa, an average grain size D (m) satisfies Formula (4), and a yield elongation is 0.5% or more.

[00001]$\begin{array}{cc}\mathrm{Si}/28+\mathrm{Ti}/48+\mathrm{Nb}/93+V/51+\mathrm{Zr}/91+\mathrm{Mo}/96+\mathrm{Cr}/52>C/12750& \left(1\right)\end{array}$$\begin{array}{cc}\mathrm{Si}/28+\mathrm{Al}/27+\mathrm{Ti}/48+\mathrm{Zr}/91+\mathrm{La}/139+\mathrm{Ce}/140>N/141000& \left(2\right)\end{array}$$\begin{array}{cc}\mathrm{WH}=Y_{2.}-\mathrm{YS}& \left(3\right)\end{array}$$\begin{array}{cc}D<80-\mathrm{Si}10& \left(4\right)\end{array}$

Provided is a non-oriented electrical steel sheet having a base metal chemical composition containing, in mass %, C: 0.0040% or less, Si: more than 3.50% and 4.50% or less, Mn: less than 0.60%, Al: 0.30-0.90%, P: 0.030% or less, S: 0.0018% or less, N: 0.0040% or less, Ti: less than 0.0040%, Nb: less than 0.0050%, Zr: less than 0.0050%, V: less than 0.0050%, Cu: less than 0.200%, Ni: less than 0.500%, and a total of one or both of Sn and Sb: 0.005-0.060%, with a balance being Fe and impurities; and satisfying [4.2Si+Al+0.5Mn4.9], wherein the average crystal grain size of the base metal is more than 40 m and 140 m or less; the integration degree in the {111}orientation is 4.0 or less; and the sheet thickness of the base metal is 0.10 to 0.30 mm.