Laminated core
A laminated core includes a stack of pieces of an electrical steel sheet that have a predetermined shape resulting from processing and includes a butted portion at which portions of a processed surface of the electrical steel sheet are abutted against each other. In the electrical steel sheet, an area ratio of regions of the processed surface that have an arithmetic mean roughness Ra of 5 μm or less is 90% or greater based on a total area of the processed surface.
1 . A laminated core comprising:
a stack of pieces of an electrical steel sheet that have a predetermined shape resulting from processing; and
a butted portion at which portions of a processed surface of the electrical steel sheet are abutted against each other, wherein
in the electrical steel sheet, an area ratio of regions of the processed surface that have an arithmetic mean roughness Ra of 5 μm or less is 90% or greater based on a total area of the processed surface,
the electrical steel sheet includes a steel sheet and an insulating coating on a surface of the steel sheet, and
an area ratio of portions of the insulating coating that are present on the processed surface is 30% or less based on the total area of the processed surface, the area ratio of the portions of the insulating coating being the percentage of the processed surface that has the insulating coating.