Kawasaki Steel Corporation

Other

Jfe Steel Corporation

Nihon Shinku Gijutsu Kabushiki Kaisha

Yukio Inokuti

Yo Ito

Yoh Ito

Yasuhiro Kobayashi

Hiroshi Shimanaka

Hirotake Ishitobi

Toshihiko Funahashi

Norio Takahashi

Kazuhiro Suzuki

Hisanao Nakahara

Ujihiro Nishiike

Yoh Shimizu

Eiji Hina

Shigeko Sujita

Shigeko Ikeda

Ujiihiro Nishiike

Osamu Ohkubo

Shiqeko Sujita

Unidirectional silicon steel sheet of ultra-low iron loss and method for production thereof

A compact device for measuring crystal orientation and crystal distortion in polycrystalline materials is disclosed. The device includes a focused electron beam generator unit, a sample holder, an electron beam detector, a Kossel X-rays detector, an image processor, and a display. The device employs the Kossel X-rays reflection method to measure crystal distortion and to measure crystal orientation in the inner portion of polycrystalline materials, slightly deeper than the shallow surface, while employing the electron beam diffraction method to measure crystal orientation at the shallow surface.

Device for measuring crystal orientation and crystal distortion in polycrystalline materials

This invention can considerably improve the adhesion property of a film to a matrix surface of a silicon steel sheet by forming an interface layer such as nitride-oxide layer of one or more selected from Fe, Si, Al and B or an extremely thin base film formed by finely dispersing nitride-oxide of one or more selected from Fe, Si, Al and B in the same film components as a tension insulating film at an interface between the matrix surface and the tension insulating film, or further by immersing in an aqueous solution of a chloride mainly composed of SiCl,to dissolve the matrix surface or conducting a smoothening treatment or a pickling treatment with an aqueous solution containing SiCl,prior to the formation of the interface layer, and hence ultra-low core loss grain oriented silicon steel sheets having a core loss considerably superior to that of the conventional one and an excellent magnetostriction property can be obtained very cheaply and in a higher productivity.

Ultralow-iron-loss grain oriented silicon steel plate and process for producing the same

Ultra-low iron grain-oriented silicon steel sheet which is made by forming a ceramic tensile coating including at least inner and outer portions of a nitride and/or a carbide, the outer portion having a coefficient of thermal expansion that is lower than that of the inner portion, and wherein the outermost portion has an insulating property.

Ultra-low iron loss grain-oriented silicon steel sheet

A method for producing a grain oriented electromagnetic steel sheet exhibiting excellent magnetic flux density and excellent iron loss, including preparing a slab from steel capable of being formed into an oriented electromagnetic steel sheet, the steel comprising about 2.5 to 4.0 weight percent of Si and about 0.005 to 0.06 weight percent of Al; hot rolling the slab to a hot-rolled plate; cold rolling the hot-rolled plate up to two times, including an intermediate annealing between cold rollings, to form a cold-rolled steel sheet; decarburization and primary recrystallization annealing the steel sheet, the decarburization and primary recrystallization annealing including a first half and a second half, the decarburization and primary recrystallization annealing comprising rapidly heating the cold-rolled steel sheet at a rate of about 10.degree. C./min or more from about 450.degree. C. to a predetermined constant temperature between about 800.degree. to 880.degree. C.; nitriding the steel sheet in a nitrogen atmosphere having a dew point of about -20.degree. C. or less during the second half of the decarburization and primary recrystallization annealing; applying an annealing separation agent substantially comprising MgO to the steel sheet; and finishing annealing the steel sheet, the finishing annealing comprising a secondary recrystallization annealing and a purification annealing.

Method for making high magnetic density, low iron loss, grain oriented

In a grain oriented electromagnetic steel sheet exhibiting high magnetic flux density and low iron loss, having a composition containing about 2.5 to 4.0 weight percent of Si, and about 0.005 to 0.06 weight percent of Al, and i) at least about 95 percent by area ratio of all crystal grains in the electromagnetic steel sheet are large secondary recrystallized grains each having a diameter of about 5 to 50 mm, each having an �001! axis within about 5.degree. to the rolling direction of the sheet, and each having an �110! axis within about 5.degree. to the normal direction of the sheet face, and ii) small grains, each having a diameter of about 0.05 to 2 mm, and each having about 2.degree. to 30.degree. of relative angle between the �001! axis of the small grains and the �001! axis of the large secondary crystallized grains, the small grains being located in the large secondary crystallized grains or at the grain boundaries. By adding Sb, or Sb and Mo to the steel, magnetic properties further improve.

High magnetic density, low iron loss, grain oriented electromagnetic

A grain oriented silicon steel sheet which exhibits reduced iron loss and which contributes excellent noise characteristics when used as a material of a stacked transformer. The sheet is produced by applying electron beam irradiation a finish-annealed grain oriented silicon steel sheet, along scan paths which cross the rolling direction at a scanning speed v(cm/s) and a spacing L(cm) in the rolling direction, with an electron beam of a beam diameter d (cm) generated by a current I.sub.b (mA) and acceleration voltage V.sub.k (kV); wherein the surface energy density .alpha. (J/cm.sup.2) on the surface of said steel sheet as determined by the following formula (1) is about 0.16 J/cm.sup.2 or more, and said surface energy density .alpha. (J/cm.sup.2) and the surface energy density .beta. (J/cm.sup.2) on the scan paths meet the approximate condition of the following formula (3):

Method of producing low iron loss, low-noise grain-oriented silicon

A method of producing a low iron loss grain oriented silicon steel sheet which generates improved magnetostrictive characteristics when used as a stacked iron core and low noise when used in a stacked transformer, as well as superior shape characteristics. A grain oriented finish-annealed silicon steel sheet is coated with an insulating film. The surface of the grain oriented silicon steel sheet is irradiated with an electron beam along a multiplicity of spaced paths so as to refine the magnetic domains. The irradiation with the electron beam is conducted continuously or intermittently along a waveform path on the surface of the grain oriented silicon steel, and the wave-form, such as a zigzag form, has a period length much smaller than the width of the grain oriented silicon steel sheet, and line interconnecting the centers of successive waves extends substantially perpendicularly to the direction of rolling of the grain oriented silicon steel sheet.

Method of producing low iron loss grain-oriented silicon steel sheet

In grain oriented silicon steel sheets provided with surface layer after finish annealing, microareas of the surface layer are locally pushed into at least an inside of base metal through electron beam irradiation in a direction substantially perpendicular to the rolling direction of the sheet, whereby iron loss of the sheet is considerably reduced.

Low iron loss grain oriented silicon steel sheets and method of

It is a technical subject to advantageously avoid the degradation of surface properties in a low iron loss grain oriented silicon steel sheet as a material for transformers, particularly if it is intended to thin the gauge to 0.1.about.0.25 mm. A low iron loss grain oriented silicon steel thin sheet can stably be produced without causing the degradation of performances through strain relief annealing by considering a chemical composition in steel, optimizing the rolling conditions, particularly cold rolling conditions, and further forming heterogeneous microareas onto the steel sheet surface.

Method of producing low iron loss grain oriented silicon steel thin

A differential pressure sealing apparatus and method for processing a continuously moving elongated sheet through successively different stages of vacuum. A vacuum chamber is provided with an inlet and a guide roller for the incoming sheet with the sheet urged against the guide roller over a wrap contact angle of 15 to 120 degrees. To resist the entrance of air into the chamber, a sealing structure encompasses at least portions of the entrance, the guide roller and the sheet.

Differential pressure sealing apparatus and method

An extra-low iron loss grain oriented silicon steel sheet is produced by irradiating electron beam to an insulation coating formed on a grain oriented silicon steel sheet after finish annealing in a direction crossing the rolling direction of the sheet, whereby the magnetic properties are not degraded even if the steel sheet is subjected to a strain relief annealing. If necessary, an inert gas may be introduced into the vicinity of electron beam irradiated zone of the coating.

Method of producing extra-low iron loss grain oriented silicon steel

A grain oriented electromagnetic steel sheet having a very low iron loss is obtained by subjecting a surface of base metal in the sheet after finish annealing to a particular mechanical polishing and has a surface roughness having a center-line average roughness of not more than 0.3 .mu.m after the polishing and the number of abrasive grains embedded in a layer just beneath polished surface of not more than 20,000 grains/cm.sup.2.

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Chiba, Japan

Yukio Inokuti