Grain-oriented electrical steel sheet and process for producing same

A grain-oriented electrical steel sheet comprising:

• a steel sheet;
• and
• a tension coating formed on a surface of the steel sheet,
• wherein
• the grain-oriented electrical steel sheet has an interlaminar current, as measured by an interlaminar resistance test, of 0.15 A or less,
• the steel sheet has a plurality of linear strain regions extending in a direction transverse to a rolling direction, the plurality of linear strain regions being formed by irradiating the steel sheet with an electron beam,
• the plurality of linear strain regions are formed at line intervals in the rolling direction of 15 mm or less, and
• each of the plurality of linear strain regions has closure domains, each of the closure domains having a length d along a sheet thickness direction of 65 μm or more and a length w along the rolling direction of 250 μm or less.

A process for producing a grain-oriented electrical steel sheet, the process comprising:

• forming a tension coating on a surface of a steel sheet;
• and
• continuously irradiating one side of the steel sheet having the tension coating with a focused electron beam in a width direction of the steel sheet, while scanning the focused electron beam along a direction transverse to a rolling direction,
• wherein
• as a result of the irradiating with the electron beam, a plurality of linear strain regions extending in a direction orthogonal to the rolling direction are formed at at least a surface portion of the steel sheet,
• the electron beam has an accelerating voltage of 60 kV or more and 300 kV or less,
• the electron beam has a beam diameter in a direction orthogonal to the scanning direction of 300 μm or less, and
• the electron beam has a beam diameter in the scanning direction that is at least 1.2 times the beam diameter in the direction orthogonal to the scanning direction.