Nippon Steel Corporation

Other

Nippon Steel Sumitomo Metal Corporation

Z. I. Nekrasov Iron & Steel Institute of the National Academy of Sciences of Ukraine

Takehiko Toh

Eiichi Takeuchi

Kazushige Umezawa

Hiroshi Harada

Hiroyuki Kondo

Koji Morita

Koichi Chiba

Ryuji Uemori

Akihiro Ono

Keisuke Fujisaki

Kenzo Sawada

Masamitsu Wakoh

Kiyoshi Wajima

Tokio Suzuki

Kenji Umetsu

Hajime Hasegawa

Shigeo Asai

Katsuhiro Sasai

Tingju Li

Kensuke Sassa

Kenichi Miyazawa

Masahiro Tani

Toshiaki Mizoguchi

Hideaki Yamamura

Shinichi Fukunaga

Yoshiyuki Ueshima

Norimasa Yamasaki

Makoto Tanaka

Kensuke Okazawa

Kenichiro Naito

Takeo Inomoto

Keiji Tsunenari

Kazuhisa Tanaka

Michitaka Matsuo

Naoto Sasaki

Takatsugu Ueyama

Yasushi Okumura

Hiroshi Hirata

Takanobu Ishii

Yasuo Maruki

Kazuo Onuki

Sohichi Niino

S I Semykin

A continuous casting device for steel of the present invention includes a casting mold for casting a molten steel, a submerged entry nozzle, an electromagnetic stirring device, and an electromagnetic brake device. Further, a curved portion which is curved toward the electromagnetic stirring device is formed at least at a position where the curved portion faces the submerged entry nozzle, on each of the long side walls. Moreover, the horizontal distance between a top of the curved portion and the submerged entry nozzle in plan view is equal to or more than 35 mm and less than 50 mm.

Continuous casting apparatus for steel

A continuous casting method of molten metal using electromagnetic force to improve the cast slab surface properties and reduce the nonmetallic inclusions and bubbles trapped inside the cast slab is provided. An alternating current is run through an electromagnetic coil arranged around a casting mold so as to surround a casting space to control the meniscus shape to improve the cast slab surface properties. The discharge ports of a submerged entry nozzle are oriented upward and the direction of the discharge flow from the discharge ports is above the intersection of the casting mold short side and meniscus.

Continuous casting method of molten metal

A cast slab has a negative segregation zone composed of a multilayer structure of negative segregation layers disposed between dendrite or crystalline layers. The dendrite or crystalline layers are a deflection structure caused by vibration during formation of the cast slab. The negative segregation layers have a distance between them of not more than 2 mm and the number of negative segregation layers is not less than 3. The cast slab has an equi-axed crystal ratio of not less than 50% inside the multilayer negative segregation zone.

Method for casting molten metal, apparatus for the same, and cast slab

In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by a fluorescent X-ray analysis method using an energy dispersion type spectroscope, or by other chemical or physical measurements, to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.

Evaluation apparatus for cleanliness of metal and method thereof

The present invention provides a continuous casting method in which vibration is given to molten metal by a shifting magnetic field so that the equi-axed crystal ratio can be enhanced and the equi-axed crystals can be made fine without generating surface defects caused by powder trapping. Further, the present invention provides an apparatus to which the continuous casting method is applied. Furthermore the present invention provides a cast slab produced by the above method and apparatus. The method of casting molten metal comprises the following steps: pouring molten metal into a mold and solidifying it in the mold while applying an electromagnetic force, which is generated by an electromagnetic coil arranged in the proximity of a molten metal pool in the mold, upon the molten metal; and vibrating the molten metal, which has been solidified in the mold while being cooled and solidified, by a shifting magnetic field generated by the electromagnetic coil so that the molten metal is accelerated by a high intensity and a low intensity of acceleration in a range not exceeding a predetermined flow velocity when the directional vectors of high acceleration and low acceleration in the same direction or in the opposite direction are combined with each other.

Method for casting molten metal

In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by dissolving the surface and extracting and filtering the inclusions to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.

An object of the present invention is to provide a process for continuously casting a molten metal which process suppresses the instability of the initial solidification and stably improves the lubrication and the surface properties of the cast metal, and an apparatus therefore, in the process for continuously casting a molten metal an alternating current is applied to an electromagnetic coil which is provided so that it surrounds a continuous casting mold wall or is embedded in the side wall of the mold, whereby an electromagnetic force is exerted on the molten metal poured into the mold which either oscillates in a constant mode or does not oscillate and is starting to be solidified the process of the present invention also comprises periodically changing the amplitude or waveform of the alternating current to be applied, and the apparatus of the present invention is used for the process.

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Futtsu, Japan

Takehiko Toh