Kawasaki Steel Corporation

Ishikawajima-harima Jukogyo Kabushiki Kaisha

Kawasaki Seitetsu Kabushiki Kaisha

Takahiro Kan

Michiro Komatsubara

Yasuyuki Hayakawa

Mitsumasa Kurosawa

Kiyoshi Shibuya

Yo Ito

Katsuo Iwamoto

Toshio Sadayori

Takuichi Imanaka

Masao Yukumoto

Hideo Kobayashi

Takashi Obara

Toru Sato

Yoshiaki Iida

Hiroshi Shimanaka

Hirotake Ishitobi

Michiharu Ozawa

Isao Matoba

Yoh Shimizu

Ko Matsumura

Tomomichi Goto

Masahiko Manabe

Yoshio Obata

Yoshiaki Tanaami

Toshio Sandayori

Kazumi Morita

Yoshinari Muro

Isamu Goto

A method of producing a non-oriented electromagnetic steel strip by subjecting a low-carbon steel slab to hot-rolling, cold rolling at a small reduction and first annealing. In order to improve magnetic flux density and surface appearance of the product, specific conditions are employed so as to coarsen the crystalline structure to obtain a controlled and moderate crystal grain size after the annealing. The slab is cold-rolled at a rolling reduction of about 5 to 15% and is subjected to first annealing by heating at a rate of about 3.degree. C./sec or higher and holding the strip for about 5 to 30 seconds at 850.degree. C. to the A.sub.3 transformation temperature of the steel, while controlling the crystal grain size to about 100 to 200 .mu.m after first annealing.

Method of producing non-oriented electromagnetic steel strip having

In grain oriented silicon steel sheets containing MnSe as a main inhibitor, an iron loss is reduced by increasing the magnetic flux density and realizing the thinning of product thickness and fine division of crystal grains while utilizing the stability of secondary recrystallization as a merit of such a sheet. In this case, 0.02-0.30% of Cu is added to a slab of the above grain oriented silicon steel, and particularly the decarburization annealing and/or the final finish annealing are carried out under particular conditions.

Method of producing grain oriented silicon steel sheets having less iron

A method of manufacturing an oriented silicon steel sheet which achieves a high magnetic flux density while reducing the core loss. A silicon steel sheet containing Al and Sb as inhibitor components is cold-rolled once or a plurality of times. During cooling for annealing before final cold rolling, a small strain is created on the sheet and the temperature is within a certain range. Carbide precipitation is suitably controlled to precipitate carbides comparatively coarsely in grains.

Method of manufacturing an oriented silicon steel sheet having improved

An oriented silicon steel sheet having a very high magnetic flux density is produced from an oriented silicon steel containing AlN as the main inhibitor and also containing Sb by a method adapted to prevent the loss of the inhibiting ability of the surface layer of the steel, and to improve cooling conditions in annealing before the final cold rolling. The steel is hot rolled, subjected to at least one time the combination of annealing and cold rolling wherein the final cold rolling is performed with a rolling reduction of about 80 to 95%, subjected to decarburization and primary recrystallization annealing, and subjected to, after coating an annealing separation agent, final finish annealing. Before annealing is performed before the final cold rolling, a nitriding promoter is applied to the surface of the steel sheet, and the partial-pressure ratio of N.sub.2 in the atmosphere for that annealing is adjusted to a value of not less than about 20%. In this way, it is possible to stably produce an oriented silicon steel sheet that exhibits a high magnetic flux density even with a small sheet thickness.

Method of producing oriented silicon steel sheet having very high

A method of manufacturing an oriented silicon steel sheet improved in magnetic characteristics, in which a hot-rolled steel sheet of oriented silicon steel containing about 0.01 to 0.10% by weight of Al and about 0.01 to 0.04% by weight of Sb as inhibitor components is heat-treated and cold-rolled one time or two or more times to have a final thickness. In the final heat treatment and final cold rolling alone, the steel sheet is quenched from a temperature of about 900.degree. to 1,100.degree. C. to a temperature equal to or lower than about 50.degree. C., is heat-treated at about 50.degree. to 150.degree. C. for about 30 sec. to 30 min. while applying a tensile stress of about 0.5 to 20 kg/mm.sup.2, is thereafter cold-rolled by a reduction rate of about 35 to 70% in a tandem rolling method, is aged at about 200.degree. to 400.degree. C. for about 10 sec. to 10 min., and is finished by cold rolling to have the final thickness.

The production of grain oriented silicon steel sheets comprises a combination of hot rolling step, cold rolling step, decarburization and primary recrystallization annealing step, annealing separator applying step and secondary recrystallization annealing and purification annealing step. In this case, the cold rolled sheet is subjected to an electrolytic degreasing in a silicate bath containing an iron concentration of 50-5000 mg/l, and Cu is adhered to the surface(s) of the sheet after the decarburization and primary recrystallization annealing in an amount of 400-2000 mg/m.sup.2 per one-side surface.

Method of producing grain oriented silicon steel sheets having improved

A cooling roll for producing quenched thin metal tape from molten metal by the twin-roll method. The roll is made of copper or copper alloy, and the roll surface is covered with a first layer of nickel plating 0.2 to 0.6 mm thick and a second layer of chromium plating 0.02 to 0.05 mm thick. The roll has the surface which does not suffer from deformation, seizure, winding, roughening, wear, and cracking. Thus the roll can produce quenched thin metal tape with a smooth surface in a stable manner for a long time.

Cooling roll for producing quenched thin metal tape

Pressure is exerted on the interior of casting rolls with a negative crown so that the rolls may maintain a true cylindrical surface without any crown when the continuous casting operation is initiated. When the cylindrical surface of the rolls is heated by molten metal as the continuous casting operation continues, the interior pressure of the rolls is decreased, whereby the rolls may maintain a true cylindrical surface without any crown.

Method and apparatus for continuous casting of metal sheet

A process and an apparatus for producing rapidly solidified metallic tapes by a double-roll system are disclosed, wherein molten metal is poured into a kissing region defined between a fixed cooling roll and a movable cooling roll through a nozzle located thereabove and rapidly solidified at the kissing region to form a metallic tape. In this case, pushing forces added to the movable cooling roll by hydraulic cylinders at driving and operational sides are controlled by adding to or subtracting from a standard pushing force an adjusting quantity of the pushing force as a function of a difference between a roll gap at the driving side and a roll gap at the operational side.

Process and apparatus for the production of rapidly solidified metallic

A double roll type method and apparatus for producing a thin metallic sheet by pouring a molten metal of a desired composition into a kissing region between two cooling rolls rotating in opposite directions, and rapidly cooling and solidifying the molten metal while it passes through the kissing region. The thin sheet which has come out of the kissing region is forcibly deflected by gas from a gas applying head and by a pair of pinch rolls so as to make close contact with one of the two cooling rolls over a predetermined region in the circumferential direction of the roll.

Method of and apparatus for producing thin metallic sheet by rapid

Single-oriented electrical steel sheets having a high magnetic induction are produced by combining specifically limited conditions in the composition of raw material, the final cold rolling reduction rate and in the secondary recrystallizing annealing.

Method for producing single-oriented electrical steel sheets having a

Electrical steel sheets having a very high magnetic induction are produced by a method in which an electrical steel raw material is hot rolled and annealed and subjected to at least one cold rolling and to a decarburizing annealing and a final annealing to develop the secondary recrystallized grains of (110) [001] orientation characterized in that the raw material contains less than 4.5% of Si, less than 0.06% of C, 0.005-0.100% of Sb and 0.01-0.05% of Al in the electrical steel raw material prior to the hot rolling, annealing at a temperature of 750.degree. - 1,200.degree.C depending upon the Si content before the final cold rolling, final cold rolling at a reduction rate of 40 - 89% and fully developing the secondary recrystallized grains at a temperature range of 800.degree. - 950.degree.C in the final annealing, are carried out in the above described order.

Method for producing electrical steel sheets having a very high magnetic

Single-oriented electrical steel sheets having a high magnetic induction can be produced by hot rolling a silicon steel raw material containing less than 0.06% of C and less than 4% of Si, subjecting to annealing step and cold rolling step conveniently repeatedly to form a cold rolled steel sheet having a final gauge and subjecting to a decarburization annealing and a final annealing to develop secondary recrystallized grains having (110)[001] orientation, said silicon steel raw material being characterized in containing 0.005-0.200% of Sb and less than 0.10% of at least one of Se and S. Said final annealing for secondary recrystallization at a temperature of 800.degree.-920.degree.C gives a preferable result.

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Chiba, Japan

Takahiro Kan