Nippon Steel Corporation

Masamitsu Kubota

Takashi Kataoka

Kazutoshi Takeda

Ichiro Tanaka

Hirotoshi Tada

Hideyuki Hamamura

Nobusato Morishige

Yasuhiro Mayumi

Kazuhiko Fukutani

Toshiya Takechi

Tomoya Suenaga

Haruhiko Atsumi

Naoto Masumitsu

A grain oriented electrical steel sheet includes a base steel sheet, an oxide layer, and a tension-insulation coating. When a glow discharge spectroscopy is conducted in a region from a surface of the tension-insulation coating to an inside of the base steel sheet, a sputtering time Feat which a Fe emission intensity becomes 0.5 times as compared with a saturation value thereof and a sputtering time Feat which a Fe emission intensity becomes 0.05 times as compared with the saturation value satisfy 0.01<(Fe−Fe)/Fe<0.35. Moreover, a magnetic flux density B8 in a rolling direction of the grain oriented electrical steel sheet is 1.90 T or more.

Grain oriented electrical steel sheet, forming method for insulation coating of grain oriented electrical steel sheet, and producing method for grain oriented electrical steel sheet

A grain oriented electrical steel sheet includes a base steel sheet, an oxide layer, and a tension-insulation coating. When a glow discharge spectroscopy is conducted in a region from a surface of the tension-insulation coating to an inside of the base steel sheet, a sputtering time Feat which a Fe emission intensity becomes 0.5 times as compared with a saturation value thereof and a sputtering time Feat which a Fe emission intensity becomes 0.05 times as compared with the saturation value satisfy (Fe−Fe)/Fe≥0.35. A maximal point of a Cr emission intensity is included between the Feand the Fe. Moreover, a magnetic flux density B8 in a rolling direction of the grain oriented electrical steel sheet is 1.90 T or more.

A method for manufacturing a grain-oriented electrical steel sheet according to an aspect of the present invention includes a step of obtaining a hot-rolled steel sheet by carrying out hot rolling on a slab containing a predetermined component composition with a remainder including Fe and impurities, a step of obtaining a hot-rolled annealed sheet by carrying out hot-rolled sheet annealing as necessary, a step of carrying out pickling to obtain a pickled sheet, a step of carrying out cold rolling to obtain a cold-rolled steel sheet, a step of carrying out primary recrystallization annealing, a step of applying an annealing separating agent including MgO to a surface and then carrying out final annealing to obtain a final-annealed sheet, and a step of applying an insulating coating and then carrying out flattening annealing.

Method for manufacturing grain-oriented electrical steel sheet and grain-oriented electrical steel sheet

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Tokyo, Japan

Masamitsu Kubota