Grain-oriented electrical steel sheet and method for magnetic-domain-refinement thereof

A grain oriented electrical sheet, comprising:

• a plurality of deformed parts formed on a surface of the electrical sheet along a rolling direction,
• wherein an interval between the deformed parts is changed over an entire length of the sheet in response to an index Ks of sensitivity calculated by Equation 1 below, and
• at least two areas having a different interval between the deformed parts exist.
• Ks=(0.7×Ds+0.3×B8)/10 [Equation 1]
• (in Equation 1, Ks denotes an index of sensitivity, Ds denotes a particle size of grain (mm), and B8 denotes a magnetic flux density T measured at magnetic field strength of 800 A/m.)

An grain oriented electrical sheet, comprising:

• a plurality of deformed parts formed on a surface of the electrical sheet along a rolling direction;
• wherein angles of the deformed part and a rolling vertical direction are changed over an entire length of the sheet in response to an index Ks of sensitivity calculated by Equation 1 below, and
• there are at least two areas having different angles of the deformed part and the rolling vertical direction.
• Ks=(0.7×Ds+0.3×B8)/10 [Equation 1]
• (in Equation 1, Ks denotes an index of sensitivity, Ds denotes a particle size of grain (mm), and B8 denotes a magnetic flux density T measured at magnetic field strength of 800 A/m.)

A method for refining magnetic domains in a grain oriented electrical sheet, the method comprising:

• measuring a particle size of grain and a magnetic flux density of the sheet;
• calculating an index Ks of sensitivity of Equation 1 below based on the measured particle size of grain and magnetic flux density value;
• and
• forming a deformed part by determining an interval between the deformed parts in response to the index Ks of sensitivity,
• wherein the deformed part is formed so that there are at least two areas in which an interval between the deformed parts is different.
• Ks=(0.7×Ds+0.3×B8)/10 [Equation 1]
• (in Equation 1, Ks denotes an index of sensitivity, Ds denotes a particle size of grain (mm), and B8 denotes a magnetic flux density T measured at magnetic field strength of 800 A/m.)