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

A motor core comprising a stator core and a rotor core formed by laminating a non-oriented electrical steel sheet having a chemical composition comprising C:

• not more than 0.005 mass %, Si:
• 2.8 to 6.5 mass %, Mn:
• 0.05 to 2.0 mass %, Al:
• not more than 3.0 mass %, P:
• not more than 0.20 mass %, S:
• not more than 0.005 mass %, N:
• not more than 0.005 mass %, Ti:
• not more than 0.003 mass %, V:
• not more than 0.005 mass %, and Nb:
• not more than 0.005 mass %, provided that Si, Mn and Al satisfy Si-2Al-Mn≥0, and the remainder being Fe and inevitable impurities, wherein
• an average value of magnetostriction λp-p (L) in a rolling direction and magnetostriction λp-p (C) in a direction perpendicular to the rolling direction at a frequency of 400 Hz and a magnetic flux density of 1.0 T is not more than 4.5×10−6 and an area ratio of recrystallized crystal grains at a section in the rolling direction of the steel sheet is 40 to 95% and an average grain size is 10 to 40 μm, wherein
• an average crystal grain size of the rotor core is 10 to 40 μm and an average crystal grain size of the stator core is not less than 80 μm.