Low iron loss and low noise grain-oriented electrical steel sheet and a method for producing the same

A low iron loss and low noise grain-oriented electrical steel sheet, having:

• εOC, an absolute value deviated by forming a tension film from a standard value which is defined as εO in the state that a tension film substantially does not exist and laser is not irradiated, and εOL, an absolute value deviated by irradiating laser after the film formation from the same standard value, satisfying the following expressions;
• εOC<3.0×10−6
• εOL<1.0×10−6,
• wherein εO is defined as a zero-peak value of magnetostriction vibration when a grain-oriented electrical steel sheet is magnetized up to a saturated magnetic flux density at the frequency of 50 Hz in the rolling direction;
• and
• ε17C, an absolute value deviated by forming a tension film from a standard value which is defined as ε17 in the state that a tension film substantially does not exist and laser is not irradiated, and ε17L, an absolute value deviated by irradiating laser after the film formation from the same standard value, satisfying the following expressions;
• ε17C<1.5×10−6
• ε17L<0.3×10−6,
• wherein ε17 is defined as the value obtained by subtracting a zero-peak value of magnetostriction vibration at the magnetization magnetic flux density of 1.7 T from a zero-peak value of magnetostriction vibration at a saturated magnetic flux density at the frequency of 50 Hz in the rolling direction;
• and further λ17, a zero-peak value of magnetostriction vibration at the magnetization magnetic flux density of 1.7 T, satisfying the following expression;
• −0.5×10−6≦λ17≦0.5×10−6;
• when magnetizing a grain-oriented electrical steel sheet at the frequency of 50 Hz in the rolling direction and measuring a zero-peak value (0-p value) of magnetostriction vibration in the rolling direction.