Nippon Steel Corporation

Sanyo Denki Co., Ltd.

Takashi Kataoka

Ichiro Tanaka

Kazutoshi Takeda

Nobusato Morishige

Haruhiko Atsumi

Shunsuke Okumura

Tomoya Suenaga

Yoshiyuki Ushigami

Hideyuki Hamamura

Ryutaro Yamagata

Hirotoshi Tada

Hiroyasu Fujii

Masamitsu Kubota

Yuki Kunita

Masaru Takahashi

Hiroshi Fujimura

Fumiaki Takahashi

Shinsuke Takatani

Kenichi Murakami

Seiki Takebayashi

Yasuhiro Mayumi

Shinji Yamamoto

Satoshi Arai

Atsushi Suzuki

Shuichi Nakamura

Masato Yasuda

Shinya Yano

Yoshihiro Suwa

Kazumi Mizukami

Shingo Okada

Yoshihiro Arita

Shohji Nagano

Kazuhiko Fukutani

Tomohito Tanaka

Teruyuki Tamaki

Toshiya Takechi

Masaki Miyashita

Takeo Aramaki

Masataka Iwaki

Naoto Masumitsu

Shin Furutaku

Noriyoshi Kubota

Ryosuke Tomioka

Noriaki Kasuga

Ushigami Yoshiyuki

This grain-oriented electrical steel sheet includes a base steel sheet having a predetermined chemical composition, a glass coating formed on the base steel sheet, and a tension-applied insulation coating formed on the glass coating, on a front surface of the base steel sheet, a plurality of linear strains that extend continuously or intermittently in a direction intersecting with a rolling direction are present, intervals p in the rolling direction of the plurality of linear strains adjacent to each other are 3.0 to 9.0 mm, widths of the linear strains are 10 to 250 μm, and, in an X-ray topographic spectrum in a range of 1.50 mm in the rolling direction that is obtained from an X-ray topographic image of the front surface and includes the linear strain at a center, a full width at half maximum of a peak of the X-ray topographic spectrum including a maximum value of a spectral intensity is 0.02 mm or more and 0.10 mm or less.

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 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 steel sheet, an insulation coating disposed on the steel sheet, and a spinel present at a part on the steel sheet at an interface between the steel sheet and the insulation coating by being fitted into the insulation coating, in which an amount of the spinel is 5 to 50 mg/mper unit area of a surface of the steel sheet.

Grain-oriented electrical steel sheet and manufacturing method of the same

This manufacturing method of a grain-oriented electrical steel sheet is a manufacturing method of a grain-oriented electrical steel sheet having no forsterite film, in which in a decarburization annealing process, a cold-rolled steel sheet is (i-1) heated at an average heating rate (HR1) of 40 to 500° C./sec in a temperature range of 550° C. or higher and lower than 720° C., (i-2) heated at an average heating rate (HR2), which is 5 to 50° C./sec, in a temperature range of 720° C. to T1° C. (770° C.≤T1 (° C.)≤900° C.), and (ii) retained at the temperature of T1° C. for 50 to 1000 seconds to make an amount of C 25 ppm or less in an atmosphere of an oxygen partial pressure (P1) which is 0.0010 to 0.20.

Manufacturing method of 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 the iron oxide layer is analyzed by a fourier transform infrared spectroscopy, an absorbance Aat 650 cmand an absorbance Aat 1250 cmsatisfy 0.2≤A/A≤5.0. Moreover, a magnetic flux density B8 in a rolling direction of the grain oriented electrical steel sheet is 1.90 T or more.

The grain-oriented electrical steel sheet is a grain-oriented electrical steel sheet which does not have an inorganic coating containing forsterite as a main component, including a base steel sheet having a predetermined chemical component, a silicon-containing oxide layer provided on the base steel sheet, an iron-based oxide layer provided on the silicon-containing oxide layer, and a tension-insulation coating provided on the iron-based oxide layer, having a thickness of 1 to 3 μm, and containing phosphate and colloidal silica as main components. When elemental analysis is performed from a surface of the tension-insulation coating in a sheet thickness direction by glow discharge optical emission spectrometry, predetermined requirements are satisfied.

A grain oriented electrical steel sheet includes: by mass %, 0.010% or less of C; 2.50 to 4.00% of Si; 0.010% or less of acid soluble Al; 0.012% or less of N; 1.00% or less of Mn; 0.020% or less of S; and a balance comprising Fe and impurities, and has a tension-insulation coating at steel sheet surface and a SiOintermediate oxide film layer with an average thickness of 1.0 nm to 1.0 μm at an interface between the tension-insulation coating and the steel sheet surface. In the grain oriented electrical steel, when a surface of the intermediate oxide film layer is analyzed by an infrared reflection spectroscopy, a peak intensity Iat 1250 cmand a peak intensity Iat 1200 cmsatisfy I/I≥0.010.

Grain oriented electrical steel sheet and producing method thereof

A motor control apparatus includes: a motor; an inverter circuit configured to drive the motor; a first wiring connecting the motor and the inverter circuit; a second wiring connecting the motor and the inverter circuit; a first sensor configured to detect a first current flowing through the first wiring; a second sensor configured to detect a second current flowing through the second wiring; and a dynamic braking circuit, and the dynamic braking circuit is connected between the first sensor and the motor and between the second sensor and the inverter circuit.

Motor control apparatus

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

A grain-oriented electrical steel sheet comprises a base steel sheet and a glass coating that is formed on the surface of the base steel sheet, and is characterized in that: the base steel sheet contains as chemical components, in mass %, 0.010% or less of C, from 2.00% to 4.00% of Si, from 0.05% to 1.00% of Mn, from 0.010% to 0.065% of Al, 0.004% or less of N and 0.010% or less of S, with the balance of Fe and impurities, wherein the oxygen concentration in the glass coating and the base steel sheet is 2,500 ppm or less; and if Iis the first peak intensity of Al and Iis the second peak intensity of Al in the concentration profile of Al, the relationship of mathematical formula (1) I<Iis satisfied.

Grain-oriented electrical steel sheet

An input power monitoring circuit includes a rectifier circuit, a divided voltage generator circuit, a divided voltage comparator circuit, a switching circuit, and a computing device. The divided voltage comparator circuit is configured in such a manner that polarity of an output signal that is outputted from a first comparator upon a first rectified divided voltage exceeding a first comparison voltage is opposite to polarity of an output signal that is outputted from a second comparator upon a second rectified divided voltage exceeding a second comparison voltage. Output terminals of the first and second comparators are connected to each other. A connection point between the output terminals of the first and second comparators is connected to an input terminal of the switching circuit. The computing device measures frequency of a pulse signal outputted from the switching circuit, and determines the voltage state of input power based on the measured frequency.

Input power monitoring circuit

A grain-oriented electrical steel sheet is a grain-oriented electrical steel sheet which does not have an inorganic coating containing forsterite as a main component and which includes: a base steel sheet containing a prescribed chemical component; a silicon-containing oxide layer provided on the base steel sheet; an iron-based oxide layer provided on the silicon-containing oxide layer; and a tension-insulation coating provided on the iron-based oxide layer, having a thickness of 1 to 3 μm, and containing phosphate and colloidal silica as main components. When the tension-insulation coating undergoes elemental analysis using a glow discharge optical emission spectrometry in a sheet thickness direction from a surface of the tension-insulation coating, a peak Si emission intensity satisfies a prescribed requirement.

The grain-oriented electrical steel sheet according to the present embodiment is a grain-oriented electrical steel sheet having a base steel sheet (), an intermediate layer () disposed to be in contact with the base steel sheet (), and an insulation coating () disposed to be in contact with the intermediate layer (). The grain-oriented electrical steel sheet according to the present embodiment includes a surface of the base steel sheet () having a strain region (D) which extends in a direction intersecting a rolling direction of the base steel sheet (), and a crystalline phosphorus oxide MPOpresent in the insulation coating () on the strain region (D) in a cross-sectional view of a surface parallel to the rolling direction and a sheet thickness direction of the base steel sheet (). (M means at least one or both of Fe and Cr.)

Grain-oriented electrical steel sheet and method for manufacturing the same

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.

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Tokyo, Japan

Takashi Kataoka