Nippon Steel Corporation

Hirotoshi Tada

Kazutoshi Takeda

Ichiro Tanaka

Takashi Kataoka

Nobusato Morishige

Hiroyoshi Yashiki

Kenichi Murakami

Yoshiaki Natori

Haruhiko Atsumi

Masamitsu Kubota

Shin Furutaku

Satoshi Arai

Masaru Takahashi

Hideyuki Hamamura

Satoshi Kano

Takeo Aramaki

Naoto Masumitsu

Ryosuke Tomioka

Junichi Takaobushi

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

This grain-oriented electrical steel sheet includes a base steel sheet, a forsterite-based primary film disposed on a surface of the base steel sheet, and a phosphate-based tension-imparting film containing no chromium, which is disposed on a surface of the primary film. In a case where a Ti content and a S content are respectively expressed as XTi and XS, by mass %, the forsterite-based primary film satisfies Expression (1) and Expression (2). A strain-introduced magnetic domain control is performed on the grain-oriented electrical steel sheet0.10≤XTi/XS≤10.00  Expression (1)XTi+XS≥0.10 mass %.  Expression (2)

Grain-oriented electrical steel sheet and method for manufacturing same

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 grain-oriented electrical steel sheet includes: a silicon steel sheet including Si and Mn; a glass film arranged on a surface of the silicon steel sheet; and an insulation coating arranged on a surface of the glass film, wherein the glass film includes a Mn-containing oxide.

Grain-oriented electrical steel sheet and method for producing thereof

A grain-oriented electrical steel sheet includes: a base steel sheet having a predetermined chemical composition; a glass coating provided on the surface of the base steel sheet; and a tension-applying insulation coating provided on the surface of the glass coating, in which linear thermal strains having, a predetermined angle (&#x3c6;) with respect to a transverse direction which is a direction orthogonal to a rolling direction are periodically formed on the surface of the tension-applying insulation coating at predetermined intervals along the rolling direction, a full width at half maximum F1 on the linear thermal strain and a full width at half maximum F2 at an intermediate position between the two linear thermal strains adjacent to each other satisfy 0.00&#x3c;(F1&#x2212;F2)/F2&#x2264;0.15, the width of the linear thermal strain is 10 &#x3bc;m or more and 300 &#x3bc;m or less, and in the base steel sheet, an orientation distribution angle &#x3b3; around a rolling direction axis of secondary recrystallization grains, an orientation distribution angle &#x3b1; around an axis parallel to a normal direction, and an orientation distribution angle &#x3b2; around an axis perpendicular to each of the RD axis and the ND axis in units of &#xb0; satisfy 1.0&#x2264;&#x3b3;&#x2264;8.0 and 0.0&#x2264;(&#x3b1;+&#x3b2;)&#x2264;10.0.

Grain-oriented electrical steel sheet and method for producing grain-oriented electrical steel sheet

A grain-oriented electrical steel sheet includes a steel layer and an insulation coating arranged in directly contact with the steel layer thereon. The steel layer includes, as a chemical composition, by mass %, 2.9 to 4.0% of Si, 2.0 to 4.0% of Mn, 0 to 0.20% of Sn, and 0 to 0.20% of Sb. In the steel layer, a silicon content and a manganese content expressed in mass % satisfy 1.2%&#x2264;Si&#x2212;0.5&#xd7;Mn&#x2264;2.0%, and a tin content and an antimony content expressed in mass % satisfy 0.005%&#x2264;Sn+Sb&#x2264;0.20%.

Grain-oriented electrical steel sheet

Provided is a method of manufacturing a grain-oriented electrical steel sheet including: a heating process of heating a slab having a predetermined chemical composition at T1&#xb0; C. of 1150&#xb0; C. to 1300&#xb0; C., retaining the slab for 5 minutes to 30 hours, lowering the temperature of the slab to T2&#xb0; C. of T1&#x2212;50&#xb0; C. or lower, heating the slab at T3&#xb0; C. of 1280&#xb0; C. to 1450&#xb0; C., and retaining the slab for 5 minutes to 60 minutes; a hot-rolling process of hot-rolling the slab that is heated to obtain a hot-rolled steel sheet; a cold-rolling process; an intermediate annealing process of performing intermediate annealing with respect to the hot-rolled steel sheet at least one time before the cold-rolling process or before a final pass of the cold-rolling process after interrupting the cold-rolling; an annealing separating agent applying process; and a secondary film applying process. In the cold-rolling process, a retention treatment is performed during a plurality of passes. In the retention treatment, retention at a temperature T&#xb0; C. satisfying 170+[Bi]&#xd7;5000&#x2264;T&#x2264;300 is performed one time to four times. A heating rate in the decarburization annealing process is 50&#xb0; C./second or faster.

Method of manufacturing grain-oriented electrical steel sheet

An electrical steel sheet includes: a specific chemical composition; a crystal grain diameter of 20 &#x3bc;m to 300 &#x3bc;m; and a texture satisfying Expression 1, Expression 2, and Expression 3 when the accumulation degree of the (001)[100] orientation is represented as Iand the accumulation degree of the (011)[100] orientation is represented as I.&#x2265;10.5&#x2003;&#x2003;Expression 1&#x2265;0.50&#x2003;&#x2003;Expression 2&#x2265;2.5&#x2003;&#x2003;Expression 3

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Himeji, Japan

Hirotoshi Tada