Jfe Steel Corporation

Showa Denko K.k.

Takashi Terashima

Toshito Takamiya

Makoto Watanabe

Karin Kokufu

Ryuichi Suehiro

Shigehiro Takajo

Masanori Uesaka

Takumi Umada

Yasuyuki Hayakawa

Hiroi Yamaguchi

Yasuaki Wakizaka

Hiroshi Matsuda

Hideyuki Takahashi

Yukihiro Shingaki

Yuichi Kamijo

Yoshihito Yokoyama

Yoshiki Shimodaira

Takeshi Imamura

Kunihiro Senda

Chiaki Sotowa

Tomoyuki Okubo

Minoru Takashima

Masayasu Nagoshi

Akinori Sudoh

Takuya Yamada

Kazutoshi Hanada

Tomohiro Abe

Yuiko Wakisaka

Naoto Kawaguchi

Tomohiro Matsushima

Yoshikuni Sato

Masanori Takenaka

Yusuke Shimoyama

Naoyuki Imai

Masahiro Suemune

In determining the conditions for final annealing, information on the concentration of enriched components over the entire length and width of the steel sheet after decarburization annealing is obtained, the optimum function of product properties in the relationship between enriched components and control conditions for final annealing is obtained in advance, and the distribution of the control conditions for final annealing within the coil were considered while determining the control conditions for final annealing such that the area where the deviation of the product properties from the above optimum function is within a range of ±δ is maximized over the entire length and width.

Method of determining final annealing conditions for grain-oriented electrical steel sheet and method of producing grain-oriented electrical steel sheet using method of determining thereof

A method of stably producing grain-oriented electrical steel sheets with excellent film properties and magnetic properties that comprises subjecting a steel slab containing predetermined additive elements to hot rolling; subjecting the hot-rolled sheet to cold rolling to have a final sheet thickness; subjecting the cold-rolled sheet to decarburization annealing; applying an annealing separator having MgO as a main component to the decarburization annealing sheet; and subjecting the decarburization annealing sheet to finish annealing. The main component of the annealing separator has a BET specific surface area ratio HO/Nof 0.6 to 1.6 and a percentage of particles with a particle size of 40 μm or more in a slurry state of 5 mass % or less.

Method of producing grain-oriented electrical steel sheet

Provided is a method of manufacturing a grain-oriented electrical steel sheet with which a grain-oriented electrical steel sheet with excellent magnetic properties and little variation in iron loss in the longitudinal direction of a coil can be stably manufactured. The method includes subjecting a steel slab to hot-rolling and optionally to annealing, then performing cold rolling once or twice or more to obtain a cold-rolled sheet with a final sheet thickness, and then subjecting the cold-rolled sheet to decarburization annealing and then secondary recrystallization annealing, where immediately before final cold rolling, a steel sheet is heated at a heating rate of 100° C./s or more to a heating temperature of 100° C. or higher and 350° C. or lower, and a time from when the steel sheet reaches the heating temperature to when it is bitten in a first pass of final cold rolling is set to within 5 seconds.

Method of manufacturing grain-oriented electrical steel sheet

Provided is a method of producing a grain-oriented electrical steel sheet having uniform and good coating properties and magnetic properties throughout the length and/or width of the steel sheet. The method comprises: subjecting a steel slab to hot rolling, to cold rolling once or twice or more with intermediate annealing therebetween, and to primary recrystallization annealing; applying a liquid or slurry annealing separator to a resultant steel sheet; and thereafter coiling the steel sheet and subjecting the steel sheet to final annealing, wherein, before, after, or simultaneously with the application of the annealing separator, an additive for changing a composition of the annealing separator is adhered to the steel sheet at a weight ratio of 15% or less to a total of the annealing separator and the additive so as to vary the composition of the annealing separator in a longitudinal direction and/or width direction of the steel sheet.

Method of producing grain-oriented electrical steel sheet and annealing separator application line

A grain oriented electrical steel sheet has excellent insulation property and includes: a steel sheet; and a coating disposed on each of both surfaces of the steel sheet, wherein an interlaminar current value after a rubbing test is not more than 0.10 A, the rubbing test being conducted by stacking two sheets of the grain oriented electrical steel sheet and rubbing the two sheets against each other to make 90 reciprocations under conditions of a surface pressure of 200 Pa, a rubbing speed of 0.10 m/s, and a reciprocating stroke of 50 mm.

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

A production method for a treatment solution for forming an insulating coating. The method includes mixing a solution A containing, on a PObasis, 0.20 mol/L or more and 10 mol/L or less of at least one of (i) phosphoric acid and (ii) a phosphate salt, and containing, on a metal basis, less than 0.50 mol/L of one or more particulate metal compounds, and a solution B containing, on a metal basis, 0.50 mol/L or more and 20.0 mol/L or less of the one or more particulate metal compounds, and containing, on a PObasis, less than 0.20 mol/L of at least one of (i) phosphoric acid and (ii) a phosphate salt, and stirring with a turbine stator-type high-speed stirrer such that a peripheral speed of a turbine reaches 10 m/s or more within 60 seconds after starting the mixing of the solution A and the solution B.

Production method for treatment solution for forming insulating coating, production method for steel sheet having insulating coating, and production apparatus for treatment solution for forming insulating coating

A grain-oriented electrical steel sheet has a base film composed mainly of forsterite on a surface of the grain-oriented electrical steel sheet and an insulating film containing mainly silicate-phosphate glass which is formed on a surface of the base film, in which, by controlling concentrations of Sr, Ca, and Ba in the base film and the insulating film to have specified gradients, the adhesion property and film tension of the insulating film are improved.

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

A treatment agent for chromium-free insulating coating formation suitable for forming an insulating coating on a surface of a grain-oriented electrical steel sheet. The treatment agent includes components (A), (B), (C), and (D). The component (B) is contained in an amount of 50 to 150 parts by mass on a SiOsolid basis, and the component (C) is contained in an amount of 5.0 parts by mass or more on an elemental metal basis, the amounts being based on 100 parts by mass, on a solid basis, of the component (A). The component (D) is contained in an amount that a molar ratio of Mand M, each being a metal element in the treatment agent for chromium-free insulating coating formation, to a phosphorus element P satisfies a specified relationship, and the treatment agent for chromium-free insulating coating formation has a pH of less than 4.5.

Treatment agent for chromium-free insulating coating formation, insulation-coated grain-oriented electrical steel sheet, and method for manufacturing the same

Provided is an annealing separator with which a grain-oriented electrical steel sheet having a forsterite film with excellent appearance uniformity and adhesion can be obtained. The annealing separator for grain-oriented electrical steel sheet comprises: magnesia that contains 0.05 mass % or more and 0.20 mass % or less of B and 0.01 mass % or more and 0.10 mass % or less of P, and titanium oxide in 1.0 part by mass or more and 10.0 parts by mass or less per 100 parts by mass of the magnesia where the titanium oxide contains one or more types of alkali metals in a total amount of 0.0050 mass % or more and 0.50 mass % or less, where an amount of P adsorbed on per 1 g of the titanium oxide is 1.5×10g or more and 1.0×10g or less.

Annealing separator for grain-oriented electrical steel sheet and method of producing grain-oriented electrical steel sheet

An electrical steel sheet with an insulating film, the steel sheet having an insulating film containing a crystalline fibrous material on a surface of the steel sheet, in which a ratio (L/L) of a length in a rolling direction (L) of the crystalline fibrous material in a cross section in the rolling direction of the insulating film to a length in a direction perpendicular to the rolling direction (L) of the crystalline fibrous material in a cross section in the direction perpendicular to the rolling direction of the insulating film is 1.5 or more and 50.0 or less.

Electrical steel sheet with insulating film

Provided is a grain-oriented electrical steel sheet having a film that is effective for the magnetic properties of the steel sheet and particularly effective for iron loss reduction and has favorable adhesion. In a grain-oriented electrical steel sheet, an insulating film partially enters into a steel substrate to form an anchor part, a depth of the anchor part from the surface of the steel substrate is 3.5 μm or less, and a number of neck parts of 5 μmor less in area is 0.06/μmor less and a number of neck parts of 10 μmto 40 μmin area is 0.005/μmor more and 0.011/μmor less, where each neck part is a remaining part of the insulating film on the surface of the steel substrate when peeling the insulating film from the steel substrate in a bend test for the grain-oriented electrical steel sheet.

Grain-oriented electrical steel sheet and production method therefor

A method for forming a film on a surface of a steel sheet includes applying a treatment solution for forming a film containing a fibrous material to the surface of the steel sheet by using a coater under a condition in which a difference between a speed of the steel sheet and a speed of an applicator of the coater is 1.0 m/min or more, inclining the surface of the steel sheet, to which the treatment solution for forming a film has been applied, at an angle of 10° or more with respect to a horizontal plane until drying is started, and thereafter drying the steel sheet.

Method for forming film and method for manufacturing electrical steel sheet with insulating film

An insulating coating treatment liquid for forming a chromium-free insulating coating on a surface of a grain-oriented electrical steel sheet, the insulating coating treatment liquid including at least one phosphate salt selected from phosphate salts of any of Mg, Ca, Ba, Sr, Zn, Al, and Mn and including colloidal silica and particles of a metal-element-containing compound. A content of the colloidal silica in terms of SiO, on a solids basis, is 50 to 120 parts by mass, and a content of the particles of a metal-element-containing compound in terms of elemental metal is 5 to 60 parts by mass, per 100 parts by mass of the at least one phosphate salt, and the insulating coating treatment liquid has a thixotropic index (TI) of 1.00 or greater and 10.00 or less.

Insulating coating treatment liquid, and grain-oriented electrical steel sheet having insulating coating and method for producing the same

Provided is an annealing separator with which a grain-oriented electrical steel sheet having a forsterite film with excellent appearance uniformity and adhesion can be obtained. The annealing separator for grain-oriented electrical steel sheet comprises: magnesia that contains 0.05 mass % or more and 0.20 mass % or less of B, a phosphate in 0.1 parts by mass or more and 1.0 part by mass or less in terms of P per 100 parts by mass of the magnesia, and titanium oxide in 1.0 part by mass or more and 10.0 parts by mass or less per 100 parts by mass of the magnesia where the titanium oxide contains one or more types of alkali metals in a total amount of 0.050 mass % or more and 1.0 mass % or less, where an amount of P adsorbed on per 1 g of the titanium oxide is 1.0×10g or less.

An insulating coating-attached electrical steel sheet has, on at least one surface, an insulating coating including an insulating tensile coating layer A. A tension applied to the steel sheet by an insulating tensile coating layer having a coating weight of M/2 from a surface of the insulating tensile coating layer A is 0.80×σor more, where M is a weight of the insulating tensile coating layer A, and σis the tension applied to the steel sheet by the insulating tensile coating layer A. The insulating coating-attached electrical steel sheet has excellent adhesion of the insulating coating. A method for manufacturing the insulating coating-attached electrical steel sheet is also provided.

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Tokyo, Japan

Takashi Terashima