Non-oriented electrical steel sheet with ultra-high magnetic flux density and production method thereof

A non-oriented electrical steel sheet having ultra-high magnetic flux density and low magnetic anisotropy, characterized by:

• comprising a steel containing, in terms of wt %,
• Si:
• 0.4% or less,
• Ni:
• 2.0% to 6.0%,
• Mn:
• 0.5% or less, and
• P:
• 0.01% to 0.2%,
• with the balance consisting of Fe and unavoidable impurities;
• having a magnetic flux density ±25 of 1.70T or higher and a magnetic flux density B50 of 1.80T or higher;
• and the difference between the magnetic flux density B50L measured for a sample in the longitudinal direction and the magnetic flux density B50C measured for a sample in the cross direction being 350 Gauss or less.

A non-oriented electrical steel sheet having ultra-high magnetic flux density and low core loss, characterized by:

• comprising a steel containing, in terms of wt %,
• Si:
• 0.4% or less,
• Ni:
• 2.0% to 6.0%,
• Mn:
• 0.5% or less,
• P:
• 0.01% to 0.2%,
• and further,
• C:
• 0.003% or less,
• S:
• 0.003% or less,
• N:
• 0.003% or less, and
• Ti+S+N:
• 0.005% or less,
• with the balance consisting of Fe and unavoidable impurities;
• and having a magnetic flux density B25 of 1.70T or higher, a magnetic flux density B50 of 1.80T or higher, and a core loss W15/50 after pickling, cold-rolling and annealing of 8 W/kg or less.

A non-oriented electrical steel sheet having ultra-high magnetic flux density, characterized by:

• comprising a steel containing, in terms of wt %,
• Si:
• 0.4% or less,
• Al:
• 0.5% or less,
• Ni:
• 2.0% to 6.0%,
• Mn:
• 0.5% or less, and
• P:
• 0.01% to 0.2%,
• with the balance consisting of Fe and unavoidable impurities;
• and having a magnetic flux density B25R defined by the undermentioned equation (1) of 1.65T or higher and a magnetic flux density B50R defined by the undermentioned equation (2) of 1.75T or higher,
• B25R=(B25-L+2×B25-22.5+2×B25-45+2×B25-67.5+B25-C)/8 (1),
• where
• B25-L:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction of rolling,
• B25-22.5:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction inclining at an angle of 22.5 degrees from the direction of rolling on a steel sheet surface,
• B25-45:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction inclining at an angle of 45 degrees from the direction of rolling on a steel sheet surface,
• B25-67.5:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction inclining at an angle of 67.5 degrees from the direction of rolling on a steel sheet surface,
• B25-C:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction perpendicular to the direction of rolling on a steel sheet surface,
• B50R=(B50-L+2×B50-22.5+2×B50-45+2×B50-67.5+B50-C)/8 (2),
• where
• B50-L:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction of rolling,
• B50-22.5:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction inclining at an angle of 22.5 degrees from the direction of rolling on a steel sheet surface,
• B50-45:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction inclining at an angle of 45 degrees from the direction of rolling on a steel sheet surface,
• B50-67.5:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction inclining at an angle of 67.5 degrees from the direction of rolling on a steel sheet surface,
• B50-C:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction perpendicular to the direction of rolling on a steel sheet surface.

A non-oriented electrical steel sheet having ultra-high magnetic flux density and low core loss, characterized by:

• comprising a steel containing, in terms of wt %,
• Si:
• 0.4% or less,
• Al:
• 0.5% or less,
• Ni:
• 2.0% to 6.0%,
• Mn:
• 0.5% or less,
• P:
• 0.01% to 0.2%,
• and further,
• C:
• 0.003% or less,
• S:
• 0.003% or less,
• N:
• 0.003% or less, and
• Ti+S+N:
• 0.005% or less,
• with the balance consisting of Fe and unavoidable impurities;
• and having a magnetic flux density B25R defined by the undermentioned equation (1) of 1.65T or higher, a magnetic flux density B50R defined by the undermentioned equation (2) of 1.75T or higher, and a core loss W15/25, after pickling, cold-rolling and annealing of 8 W/kg or less,
• B25R=(B25-L+2×B25-22.5+2×B25-45+2×B25-67.5+B25-C)/8 (1),
• where
• B25-L:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction of rolling,
• B25-22.5:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction inclining at an angle of 22.5 degrees from the direction of rolling on a steel sheet surface,
• B25-45:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction inclining at an angle of 45 degrees from the direction of rolling on a steel sheet surface,
• B25-67.5:
• magnetic flux density under the magnetic field strength of 2500A/m, measured for a sample cut out in the direction inclining at an angle of 67.5 degrees from the direction of rolling on a steel sheet surface,
• B25-C:
• magnetic flux density under the magnetic field strength of 2500 A/m, measured for a sample cut out in the direction perpendicular to the direction of rolling on a steel sheet surface,
• B50R=(B50-L+2×B50-22.5+2×B50-45+2×B50-67.5+B50-C)/8 (2),
• where
• B50-L:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction of rolling,
• B50-22.5:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction inclining at an angle of 22.5 degrees from the direction of rolling on a steel sheet surface,
• B50-45:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction inclining at an angle of 45 degrees from the direction of rolling on a steel sheet surface,
• B50-67.5:
• magnetic flux density under the magnetic field strength of 5000A/m, measured for a sample cut out in the direction inclining at an angle of 67.5 degrees from the direction of rolling on a steel sheet surface,
• B50-C:
• magnetic flux density under the magnetic field strength of 5000 A/m, measured for a sample cut out in the direction perpendicular to the direction of rolling on a steel sheet surface.