Jfe Steel Corporation

Kawasaki Steel Corporation

Minoru Takashima

Takeshi Imamura

Mineo Muraki

Keiji Sato

Yasuyuki Hayakawa

Takashi Obara

Masanori Takenaka

Tomofumi Shigekuni

Seiji Okabe

Michiro Komatsubara

Hiroi Yamaguchi

Mitsumasa Kurosawa

Masaki Kawano

Yuiko Ehashi

Takashi Terashima

Tatsuhiko Hiratani

Atsuhito Honda

Tetsuo Toge

Makoto Watanabe

Kaoru Sato

Katsumi Yamada

Toshito Takamiya

Shigehiro Takajo

Takeshi Omura

Hirotaka Inoue

Yukihiro Shingaki

Masanori Uesaka

Tadashi Nakanishi

Akio Fujita

Takumi Umada

Takeshi Murai

Kenichi Sadahiro

Atsushi Ogino

Masaaki Kohno

Koji Yano

Nobuo Shiga

Kouji Yano

Hideo Yamagami

With a hot-rolled steel sheet for electrical steel sheet production having a scale layer on the surface, where the surface of the steel sheet has a lightness L* as defined in JIS Z 8781-4: 2013 satisfying 30&#x2264;L*&#x2264;50, and chromaticities a* and b* as defined in JIS Z 8781-4: 2013 satisfying &#x2212;1&#x2264;a*&#x2264;2 and &#x2212;5&#x2264;b*&#x2264;3 respectively, and with one end portion in the longitudinal direction of a coil as a reference, a color difference &#x394;E* as defined in JIS Z 8781-4: 2013 at the central portion and at the opposite end portion satisfies &#x394;E*&#x2264;8, it is possible to obtain a grain-oriented electrical steel sheet where the variation of properties in a product coil is small.

Hot-rolled steel sheet for electrical steel sheet production and method of producing same

To provide a grain-oriented electrical steel sheet that has better magnetic property than conventional ones without requiring high-temperature slab heating, in the case of not performing intermediate annealing, the hot rolled steel sheet obtained by a predetermined step is subjected to hot band annealing, and, in a heating process in the hot band annealing, heating is performed at a heating rate of 10&#xb0; C./s or less for 10 sec or more and 120 sec or less in a temperature range of 700&#xb0; C. or more and 950&#xb0; C. or less, and in the case of performing the intermediate annealing, in a heating process in final intermediate annealing, heating is performed at a heating rate of 10&#xb0; C./s or less for 10 sec or more and 120 sec or less in a temperature range of 700&#xb0; C. or more and 950&#xb0; C. or less.

Method of producing grain-oriented electrical steel sheet

Provided are: an oriented electromagnetic steel sheet with outstanding coating adhesion and magnetic properties after stress relief annealing; and a method for manufacturing the oriented electromagnetic steel sheet. The oriented electromagnetic steel sheet comprises: a steel sheet; a non-oxide ceramic coating disposed on the steel sheet and containing a non-oxide; and an insulating tensile coating disposed on the non-oxide ceramic coating and containing an oxide. The thickness of the non-oxide ceramic coating is 0.020-0.400 &#x3bc;m. The thickness of the insulating tensile coating is at least 1.0 &#x3bc;m. The chromium content on the steel plate side of the non-oxide ceramic coating is less than 25 atomic %, and the chromium content on the insulating tensile coating side of the non-oxide ceramic coating is at least 25 atomic %.

Oriented electromagnetic steel sheet and method for manufacturing oriented electromagnetic steel sheet

To provide a grain-oriented electrical steel sheet that has better magnetic property than conventional ones, in hot band annealing of the hot rolled steel sheet obtained by a predetermined step, an average heating rate from ordinary temperature to 400&#xb0; C. is set to 50&#xb0; C./s or more, and a time to reach 900&#xb0; C. from 400&#xb0; C. is set to 100 sec or less.

An electrical steel sheet has a composition including C: less than 0.010 mass %, Si: 1.5&#x2dc;10 mass % and the balance being Fe and incidental impurities, wherein a main orientation in a texture of a steel sheet is &#x3c;111&#x3e;//ND and an intensity ratio relative to randomly oriented specimen of the main orientation is not less than 5 and, preferably an intensity ratio relative to randomly oriented specimen of {111}&#x3c;112&#x3e; orientation is not less than 10, an intensity ratio relative to randomly oriented specimen of {310}&#x3c;001&#x3e; orientation is not more than 3 and Si concentration has a gradient that it is high at a side of a surface layer and low at a central portion in the thickness direction and a maximum value of the Si concentration is not less than 5.5 mass % and a difference between maximum and minimum values is not less than 0.5 mass %.

Electrical steel sheet

In a method for producing a grain-oriented electrical steel sheet by hot rolling a steel slab comprising C: 0.04-0.12 mass %, Si: 1.5-5.0 mass %, Mn: 0.01-1.0 mass %, sol. Al: 0.010-0.040 mass %, N: 0.004-0.02 mass %, one or two of S and Se: 0.005-0.05 mass % in total of S and Se, cold rolling, and subjecting to primary recrystallization annealing and further to final annealing, a content ratio of sol. Al to N in the steel slab (sol. Al/N) and a final thickness d (mm) satisfy an equation of 4d+1.52&#x2264;sol. Al/N&#x2264;4d+2.32, and the steel sheet in the heating process of the final annealing is held at a temperature of 775-875&#xb0; C. for 40-200 hours and then heated in a temperature region of 875-1050&#xb0; C. at a heating rate of 10-60&#xb0; C./hr to preform secondary recrystallization and purification treatment, whereby an extremely-thin grain-oriented electrical steel sheet having a low iron loss and a small deviation in coil is produced.

Method for producing grain-oriented electrical steel sheet

An electrical steel sheet has a component composition including, by mass %, C: 0.007% or less, Si: 4% to 10%, and Mn: 0.005% to 1.0%, the balance being Fe and incidental impurities, as well as a sheet thickness within a range of 0.01 mm or more to 0.10 mm or less, and a profile roughness Pa of 1.0 &#x3bc;m or less. The electrical steel sheet exhibits excellent iron loss properties whereby the magnetic property is free from deterioration, and degradation of the stacking factor can be avoided, even when the steel sheet with a thickness of 0.10 mm or less has been subjected to siliconizing treatment to increase the Si content in the steel.

Ultrathin electromagnetic steel sheet

A grain oriented electrical steel sheet has sufficiently low iron loss and having less conventionally-concerned warpage of the steel sheet even after the steel sheet is subjected to artificial magnetic domain refining treatment, where strain-introducing treatment is conducted with high energy so that an iron loss-reducing effect can be maximized. The grain oriented electrical steel sheet is obtained by adjusting tension to be applied to a tension-applying insulating coating, or to both surfaces of the steel sheet by the tension-applying insulating coating, before strain-introducing treatment in the range of Formula (1):1.0&#x2266;(tension applied to non-strain-introduced surface)/(tension applied to strain-introduced surface)&#x2266;2.0&#x2003;&#x2003;(1),and by controlling the amount of warpage of the steel sheet toward the strain-introduced surface side after strain-introducing treatment in the range of 1 mm or more and 10 mm or less.

Grain oriented electrical steel sheet

The present invention provides a method for manufacturing a grain oriented electrical steel sheet, including preparing as a material a steel slab having a predetermined composition and carrying out at least two cold rolling operations, characterized in that a thermal treatment is carried out, prior to any one of cold rolling operations other than final cold rolling, at temperature in the range of 500&#xb0; C. to 750&#xb0; C. for a period in the range of 10 minutes to 480 hours. The grain oriented electrical steel sheet of the present invention exhibits through utilization of austenite-ferrite transformation superior magnetic properties after secondary recrystallization.

Method for manufacturing grain oriented electrical steel sheet

A method for manufacturing a thin metal strip by pouring and rapidly solidifying molten metal onto a cooling roll rotating at a high speed to form a thin metal strip having a width of 50&#x2dc;350 mm, blowing compression gas from substantially a tangential direction of the cooling roll toward the thin metal strip to separate the thin metal strip from the cooling roll, adsorbing the separated thin metal strip with a permeable belt of a suction type belt conveyor, and transporting to a take-up reel to wind in form of a coil, the thin metal strip is adsorbed by the belt under conditions that a nearest approaching distance L between the cooling roll and the suction type belt conveyor is 2&#x2dc;50 mm and a suction width S of a suction box arranged in the suction type belt conveyor is 1.2&#x2dc;2.5 times of a width W of the thin metal strip.

Method and installation for manufacturing thin metal strip

A treatment solution for an insulation coating of grain-oriented electrical steel sheets includes at least one selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al and Mn; colloidal silica in a proportion of 0.5 to 10 mol in terms of SiO; and a water-soluble vanadium compound in a proportion of 0.1 to 2.0 mol in terms of V, relative to PO:1 mol in the phosphates.

Treatment solution for insulation coating for grain-oriented electrical steel sheets

A treatment solution for insulation coating for grain-oriented electrical steel sheets contains at least one selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn; colloidal silica in a proportion of 0.5 to 10 mol in terms of SiOand a water-soluble vanadium compound in a proportion of 0.1 to 2.0 mol in terms of V, relative to PO:1 mol in the phosphates.

Treatment solution for insulation coating for grain-oriented electrical steel sheets and method for producing grain-oriented electrical steel sheet having insulation coating

A grain oriented electrical steel sheet has grooves on one surface of the steel sheet formed for magnetic domain refining, the steel sheet including a forsterite film and a tension coating on front and back surfaces of the steel sheet, wherein the tension coating is applied on a surface with the grooves in a coating amount A (g/m) and is applied on a surface with no grooves in a coating amount B (g/m), the coating amounts A and B satisfying (1) and (2):3&#x2266;&#x2266;8&#x2003;&#x2003;(1);and1.0&#x3c;&#x2266;1.8&#x2003;&#x2003;(2).

A treatment solution for an insulation coating for a grain oriented electrical steel sheet includes at least one member selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn, and colloidal silica in a proportion of 0.5 to 10 mol in terms of SiOand at least one member selected from permanganates of Mg, Sr, Zn, Ba, and Ca in a proportion of 0.02 to 2.5 mol in terms of metal elements in the permanganates, relative to PO:1 mol in the phosphates.

Treatment solution for insulation coating for grain oriented electrical steel sheet and method for producing grain oriented electrical steel sheet having insulation coating

A treatment solution for insulation coating for grain oriented electrical steel sheet includes at least one member selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn, and colloidal silica in a proportion of 0.2 to 10 mol in terms of SiOand a titanium chelate compound in a proportion of 0.01 to 4.0 mol in terms of Ti, relative to PO: 1 mol in the phosphates.

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Tokyo, Japan

Minoru Takashima