Non-oriented electrical steel sheet, method for producing the same, and motor core

A non-oriented electrical steel sheet, comprising a chemical composition containing, in mass %,

• C:
• 0.01% or less,
• Si:
• 2.0% or more and less than 4.5%,
• Mn:
• 0.05% or more and 5.00% or less,
• P:
• 0.1% or less,
• S:
• 0.01% or less,
• Al:
• 3.0% or less, and
• N:
• 0.0050% or less,
• optionally one or more groups out of the following groups A to E:
• group A:
• Co:
• 0.0005% or more and 0.0050% or less,
• group B:
• Cr:
• 0.05% or more and 5.00% or less,
• group C:
• at least one selected from the group of
• Ca:
• 0.001% or more and 0.100% or less,
• Mg:
• 0.001% or more and 0.100% or less, and
• REM:
• 0.001% or more and 0.100% or less,
• group D:
• at least one selected from the group consisting of
• Sn:
• 0.001% or more and 0.200% or less and
• Sb:
• 0.001% or more and 0.200% or less, and
• group E:
• at least one selected from the group consisting of
• Cu:
• 0% or more and 0.5% or less,
• Ni:
• 0% or more and 0.5% or less,
• Ti:
• 0% or more and 0.005% or less,
• Nb:
• 0% or more and 0.005% or less,
• V:
• 0% or more and 0.010% or less,
• Ta:
• 0% or more and 0.002% or less,
• B:
• 0% or more and 0.002% or less,
• Ga:
• 0% or more and 0.005% or less,
• Pb:
• 0% or more and 0.002% or less,
• Zn:
• 0% or more and 0.005% or less,
• Mo:
• 0% or more and 0.05% or less,
• W:
• 0% or more and 0.05% or less,
• Ge:
• 0% or more and 0.05% or less, and
• As:
• 0% or more and 0.05% or less,
• with the balance being Fe and inevitable impurities, where Si+Al is less than 4.5%, wherein
• crystal grains in the steel sheet have an average grain size X1 of 50 μm or less, a standard deviation S1 of a crystal grain size distribution satisfies the following formula (1):
• S
• 1
• /
• X
• 1
• <
• 0
• .
• 7
• ⁢
• 5
• (
• 1
• )
• and a kurtosis K1 of the crystal grain size distribution is 20.0 or less.