Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Tadashi Nakayama

Sadami Kousaka

Norito Abe

Yoshiyuki Ushigami

Tadao Nozawa

Osamu Honjo

Shuichi Nakamura

Hiroyasu Fujii

Shinsuke Takatani

Kenichi Murakami

Yozo Suga

Norikazu Fujii

Shinji Yamamoto

Shunsuke Okumura

Nobuyuki Takahashi

Seiki Takebayashi

Shuichi Yamazaki

Satoshi Arai

Masaru Takahashi

Takashi Kataoka

Tesshu Murakawa

Masahiro Fujikura

Yasunari Yoshitomi

Tomoji Kumano

Shohji Nagano

Masato Yasuda

Tatsuhiko Sakai

Takeshi Kubota

Hideyuki Hamamura

Fumiaki Takahashi

Masaki Tanaka

Shigeru Hirano

Shinichi Matsui

Shinya Yano

Katsuro Kuroki

Koji Hirano

Kazumi Mizukami

Hiroaki Masui

Shingo Okada

Takeshi Imai

Koji Yamasaki

Masao Kurosaki

Takeshi Kimura

Osamu Tanaka

Hidekuni Murakami

Norihiro Yamamoto

Takeru Ichie

Shinichi Kanao

Makoto Atake

Kojiro Hori

Takeo Nagashima

Maremizu Ishibashi

Chie Hama

Nobusato Morishige

Takehide Senuma

Yoshihiro Arita

Masato Mizokami

Hisashi Kobayashi

Tsuyoshi Kawano

Hotaka Honma

Tsutomu Haratani

Genichi Shigesato

Kiyoshi Sawano

Toyohiko Konno

Masaaki Sugiyama

Masao Yabumoto

Kiyoshi Ueno

Hajime Komatsu

Yoshio Nakamura

Syuji Kitahara

Mikio Itoh

Masahide Urago

Fumio Kurosawa

Toshio Nishiyama

Kenichi Takimoto

Hodaka Honma

Yukio Matsuo

Yosuke Kurosaki

Katsurou Kuroki

Isao Iwanaga

Masahide Uragoh

Yohichi Zaizen

Yoichi Zaizen

Isao Koike

Toshinao Yamaguchi

Shinishi Kanao

A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PHO/PHis controlled, a final annealing process where hydrogen in mixed gas atmosphere is controlled to 50 volume % or more, an annealing separator removing process where water-washing is conducted using solution with inhibitor, a smoothing process where mixed gas and temperature are controlled for annealing, and an insulation coating forming process where a baking temperature and a heat treatment temperature are controlled.

Method for producing 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 method for manufacturing a grain-oriented electrical steel sheet includes: a silicon steel material production process of producing a silicon steel material; a hot rolling process of obtaining a hot rolled sheet by subjecting the silicon steel material to hot rolling; a cold rolling process of obtaining a steel sheet having a final sheet thickness by subjecting the hot rolled sheet to a single cold rolling process or to multiple cold rolling processes having intermediate annealing performed between cold rolling processes; a decarburization annealing process of subjecting the steel sheet to decarburization annealing using a decarburization annealing furnace including a heating area and a soaking area; and a final annealing process of applying an annealing separator having alumina as a main component to the steel sheet and subjecting the steel sheet to final annealing, wherein, in the decarburization annealing process, when X represents the Cr content of the silicon steel material in terms of mass %, an oxidation degree P1 of an atmosphere gas in the heating area satisfies the following Expression 1 and an oxidation degree P2 of an atmosphere gas in the soaking area satisfies the following Expression 2:0.18−0.008≤1≤0.25+0.15≤0.20  (Expression 1); and0.01≤2≤0.15  (Expression 2).

Method for manufacturing grain-oriented electrical steel sheet

A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PHO/PHis controlled, a final annealing process where hydrogen in mixed gas atmosphere is controlled to 50 volume % or more, an annealing separator removing process where water-washing is conducted using solution with inhibitor, a smoothing process where chemical-polished is conducted to control average roughness Ra, and an insulation coating forming process where insulation coating forming solution in which crystalline phosphide is included is applied.

This grain-oriented electrical steel sheet includes a base steel sheet, an intermediate layer that is formed on a surface of the base steel sheet and mainly contains silicon oxide, and an insulation coating that is formed on the surface of the intermediate layer. A number density of the oxide particles in a region from the surface of the base steel sheet to a depth of 10 μm toward an inside of the base steel sheet is 0.020 oxide particles/μmor less. In the grain-oriented electrical steel sheet, an area rate of an intermediate layer-remaining region n which the intermediate layer does not peel off but remains in a region in which the insulation coating peels off after a bend test performed using a mandrel according to JIS K 5600-5-1 (1999) is 20% or more.

Grain-oriented electrical steel sheet, intermediate steel sheet for grain-oriented electrical steel sheet, and methods for manufacturing same

A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PHO/PHis controlled, an annealing separator applying process where a mass ratio of MgO and AlOin an annealing separator is controlled, a final annealing process where hydrogen in mixed gas atmosphere is controlled to 50 volume % or more, an annealing separator removing process where water-washing is conducted using solution with inhibitor and then pickling is conducted, a smoothing process where mixed gas and temperature are controlled for annealing, and an insulation coating forming process where a baking temperature and a heat treatment temperature are controlled.

A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PHO/PHis controlled, an annealing separator applying process where a mass ratio of MgO and AlOin an annealing separator is controlled, a final annealing process where an oxidation degree is controlled when atmosphere includes hydrogen or a dew point is controlled when atmosphere consists of inert gas, and an insulation coating forming process where a baking temperature and a heat treatment temperature are controlled.

A grain-oriented electrical steel sheet according to an aspect of the present invention includes an underlying steel sheet and a tension-insulation coating arranged on the surface of the underlying steel sheet, and a ten-point average roughness RzL in an L direction obtained when the tension-insulation coating is removed from the grain-oriented electrical steel sheet with an alkaline solution, and then the surface of the underlying steel sheet is measured in a rolling direction is 6.0 μm or less.

Grain-oriented electrical steel sheet, and steel sheet serving as base sheet for grain-oriented electrical steel sheet

A method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PHO/PHis controlled, an annealing separator applying process where a mass ratio of MgO and MCl in an annealing separator is controlled, a final annealing process where an oxidation degree is controlled when atmosphere includes hydrogen or a dew point is controlled when atmosphere consists of inert gas without hydrogen, and an insulation coating forming process where a baking temperature and a heat treatment temperature are controlled.

A method for manufacturing a grain-oriented electrical steel sheet includes: a silicon steel material production process of producing a silicon steel material; a hot rolling process of obtaining a hot rolled sheet by subjecting the silicon steel material to hot rolling; a cold rolling process of obtaining a steel sheet of a final sheet thickness by subjecting the hot rolled sheet to a single cold rolling process or multiple cold rolling processes having intermediate annealing performed between the cold rolling processes; a decarburization annealing process of subjecting the steel sheet to decarburization annealing; and a final annealing process of applying an annealing separator containing alumina as a main component to the steel sheet and subjecting the steel sheet to final annealing.

The method for manufacturing a grain-oriented electrical steel sheet is a method for manufacturing a grain-oriented electrical steel sheet including a strain region forming process of irradiating the 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 () with an electron beam and forming a strain region (D) which extends in a direction intersecting a rolling direction of the base steel sheet () on a surface of the base steel sheet (), wherein, in the strain region forming process, a temperature of a central portion of the strain region (D) in the rolling direction of the base steel sheet () and an extension direction of the strain region (D) is heated to 800° C. or higher and 2000° C. or lower.

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 method for producing a grain oriented electrical steel sheet includes a decarburization annealing process where an oxidation degree PHO/PHis controlled and pickling is conducted after decreasing temperature, an annealing separator applying process where a mass ratio of MgO and AlOin an annealing separator is controlled, a final annealing process where an oxidation degree is controlled when atmosphere includes hydrogen or a dew point is controlled when atmosphere consists of inert gas, an annealing separator removing process where water-washing is conducted using solution with inhibitor, and an insulation coating forming process where a mass ratio of phosphoric acid and metal compound in insulation coating forming solution is controlled.

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Tokyo, Japan

Yoshiyuki Ushigami