Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Nobusato Morishige

Takashi Kataoka

Ichiro Tanaka

Ryutaro Yamagata

Haruhiko Atsumi

Kenichi Murakami

Hirotoshi Tada

Masaru Takahashi

Kazumi Mizukami

Kazutoshi Takeda

Yoshiaki Natori

Hiroyoshi Yashiki

Yasuhiro Mayumi

Tomoya Suenaga

Naoto Masumitsu

Shin Furutaku

Satoshi Arai

Yoshiyuki Ushigami

Atsushi Shibayama

Atsushi Suzuki

Hideyuki Hamamura

Masato Yasuda

Yuji Kubo

Koki Tanaka

Norikazu Fujii

Yoshihiro Suwa

Seiki Takebayashi

Takeru Ichie

Teruyuki Tamaki

Kazuhiko Fukutani

Toshiya Takechi

Hotaka Honma

Eiichi Nanba

Fuminobu Murakami

Masamitsu Kubota

Masahide Urago

Ryosuke Tomioka

Daichi Hamada

Daisuke Itabashi

Junichi Takaobushi

Grain-oriented electrical steel sheet excellent in magnetic properties and adhesion of a primary coating to a base steel sheet and with few defects where the base metal is exposed in point defects and a method for manufacturing grain-oriented electrical steel sheet are provided. This is characterized by being provided with a base steel sheet and a primary coating. The primary coating satisfies (1) Number density D3 of Al concentrated regions: 0.015 to 0.150/μm(2) (Area S5 of regions comprised of anchoring oxide layer regions and Al concentrated regions)/(area S3 of Al concentrated regions)≥0.30, (3) Distance H5 of mean value of heights in thickness direction of regions of comprised of anchoring oxide layer regions and Al concentrated regions minus H0: 0.4 to 4.0 μm, (4) (Perimeter L5 of regions comprised of anchoring oxide layer regions and Al concentrated regions)/(observed area S0): 0.020 to 0.500 μm/μ, and (5) (Area S1 of anchoring oxide layer regions)/(observed area S0)≥0.15.

Grain-oriented electrical steel sheet, finish annealing-use steel sheet, annealing separator, method for manufacturing grain-oriented electrical steel sheet, and method for manufacturing finish annealing-use steel sheet

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having MgSiOas a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 μm from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 μm/μm, and a number density of Al oxides is 0.02 to 0.20/μm.

Grain-oriented electrical steel sheet and method for manufacturing same and annealing separator

Grain-oriented electrical steel sheet and its method of manufacture are provided. The method includes a process of heating to 1280° C. or more and hot rolling a slab containing, by mass %, Bi and a predetermined composition of constituents and having a balance of Fe and impurities to obtain hot rolled steel sheet. After hot rolling annealing, the hot rolled steel sheet is cold rolled one time or more with process annealing performed interposed so as to obtain cold rolled steel sheet, followed by a process of rapidly heating then decarburization annealing the steel sheet, a process of coating the surface of the cold rolled steel sheet after decarburization annealing with an annealing separator comprising sulfates or sulfides and having MgO as its main constituent, then performing finish annealing, a process of performing strictly controlled finish annealing, and a process of coating an insulating coating, then performing flattening annealing.

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

There is provided a non-oriented electrical steel sheet in which, in a cross section of a base material in a sheet thickness direction, the number density Nof precipitates with an equivalent circle diameter of 50 to 500 nm present in a range of 2.0 to 5.0 μm from the surface of the base material in the sheet thickness direction is 0.30 pieces/μmor less, and the relationship between the number density Nand the number density Nof precipitates with an equivalent circle diameter of 50 to 500 nm present in a range from the surface of the base material to 2.0 μm satisfies Formula (1):()/()≤0.5  Formula (1).

Non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet

A grain oriented electrical steel sheet includes a base steel sheet, a glass film, and a tension-insulation coating. When a glow discharge emission spectroscopy is conducted from a surface of the glass film toward a depth direction, an analysis starting time Ts, a time Tat which Al shows a maximum emission intensity, an Al emission intensity F(T) at the T, a time Tat which Si shows a maximum emission intensity, and an Al emission intensity F(T) at the Tsatisfy 0.05≤F(T)/F(T)≤0.50 and 2.0≤(T−Ts)/(T−Ts)≤5.0.

Grain oriented electrical steel sheet

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.

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to a base steel sheet, an annealing separator utilized for manufacture of grain-oriented electrical steel sheet, and a method for manufacturing grain-oriented electrical steel sheet are proposed. The grain-oriented electrical steel sheet is provided with a base metal steel sheet containing comprising a predetermined chemical composition and a primary coating formed on a surface of the base steel sheet and comprising MgSiOas a main constituent. The primary coating satisfies the conditions of (1) the number density D3 of the Al concentrated region: 0.020 to 0.180/&#x3bc;m, (2) (total area S5 of regions which is anchoring oxide layer regions and is also Al concentrated regions)/(total area S3 of Al concentrated regions)&#x2265;33%, (3) distance H5 of mean value of length in thickness direction of regions which is anchoring oxide layer regions and is also Al concentrated regions minus H0: 0.4 to 4.0 &#x3bc;m, (4) (total area S1 of anchoring oxide layer regions)/(observed area S0)&#x2265;15%.

Grain-oriented electrical steel sheet, annealing separator, and method for manufacturing grain-oriented electrical steel sheet

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

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having MgSiOas a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 &#x3bc;m from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 &#x3bc;m/&#x3bc;m, and a number density of Al oxides is 0.02 to 0.20/&#x3bc;m.

A method for manufacturing a grain-oriented electrical steel sheet including a step of hot-rolling a slab containing a predetermined component composition with a remainder including Fe and an impurity to obtain a hot-rolled steel sheet, a step of, after carrying out hot-rolled steel sheet annealing on the hot-rolled steel sheet, carrying out cold rolling to obtain a cold-rolled steel sheet, a step of carrying out primary recrystallization annealing including a rapid temperature increase at an average temperature increase velocity V of 400&#xb0; C./s or more and imparting of a steel sheet tensile force S on the cold-rolled steel sheet, and a step of applying an annealing separating agent to a surface of the cold-rolled steel sheet after the primary recrystallization annealing and then carrying out flattening annealing.

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

A method according to the present invention has: isolating, by extraction, particles contained in a metal material to be analyzed in a solution using a particle isolator; dispersing the particles isolated by extraction into a solvent to prepare a dispersion, and fractionating the dispersion into a plurality of particle dispersions based on particle sizes, using a field flow fractionator; and irradiating laser light on each of the particle dispersions separated based on predetermined particle sizes, to thereby measure absolute values of the particle size based on angular dependence of reflection intensity, and also to thereby measure the number density based on magnitude of reflection intensity.

Method of analyzing particle size distribution of particles in metal material

Grain-oriented electrical steel sheet superior in core loss characteristic containing Si: 0.8 to 7 mass % and having a secondary recrystallized texture with a {110}&#x3c;001&#x3e; orientation as the main orientation, characterized in that average deviation angles &#x3b1;, &#x3b2;, and &#x3b3; from the {110}&#x3c;001&#x3e; ideal orientation of the secondary recrystallized texture satisfy (&#x3b1;+&#x3b2;)&#x2266;&#x3b3;, where &#x3b1;: average deviation angle from {110}&#x3c;001&#x3e; ideal orientation around rolling surface normal direction (ND) of secondary recrystallized texture, &#x3b2;: average deviation angle from {110}&#x3c;001&#x3e; ideal orientation around traverse direction (TD) of secondary recrystallized texture, and &#x3b3;: average deviation angle from {110}&#x3c;001&#x3e; ideal orientation around rolling direction (RD) of secondary recrystallized texture.

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Tokyo, Japan

Nobusato Morishige