Nippon Steel Corporation

Kawasaki Jukogyo Kabushiki Kaisha

Hiroshi Iwasaki

Hiroyuki Nakashima

Hideo Kaneko

Shogo Matsumura

Tomoaki Tanaka

Hatsuyoshi Kumashiro

Toshihiro Kosuge

Kensuke Shimomura

Haruo Ohguro

Ryuuzou Hanzawa

Kazuaki Sueoka

Mayumi Okimori

Yoji Ao

Hiroaki Morishige

Gaku Ogawa

Sadaaki Murakawa

Yukio Morimoto

Hironori Takano

Taizou Kiyosuke

Katsuhiko Kawamoto

Masaru Sadachika

Yoshikazu Nishi

Makoto Ueda

Toshio Iida

Kenichi Murai

Seishiro Saita

Nobuyuki Makino

Tatsuhito Matsushima

Masayuki Inoue

Kenji Abe

A vacuum/reduced pressure refining vessel (,) is connected, by an upstream duct (,) to a dry dust collector (,) that uses a filter (,). The dry dust collector (,) is connected to a reduced pressure evacuating apparatus (,) by a downstream duct (,), and a block valve (,) is provided in the upstream duct (,). At the start of a vacuum/reduced pressure refining treatment, a non-oxidizing gas is injected into the upstream duct at a position that is upstream of the block valve (,) to substantially replace the oxygen in the upstream duct and to hermetically close the upstream duct. After the hermetically closed state has been established in the upstream duct, the block valve (,) is opened and operation of the dry dust collector (,) is started. At the end of the vacuum/reduced pressure refining treatment, the block valve (,) is closed and only the non-oxidizing gas is injected into the upstream duct to return the pressure, and then the upstream duct is opened to atmospheric air, and preferably an open port on the side of the dry dust collector (,) is closed during a waiting period from the end of the vacuum/reduced pressure refining treatment until the start of the next vacuum/reduced pressure refining treatment.

Method for vacuum/reduced-pressure refining and facility for vacuum/reduced-pressure refining

A continuous casting method includes the steps of continuously supplying molten metal into a mold through at least one feed nozzle connected to the mold through a break ring, with the feed nozzle, the mold and the break ring forming at least a portion of a continuous casting apparatus, and intermittently withdrawing a cast piece formed from the molten metal in the mold thereby creating pressure in a space formed at a connecting point between the break ring, the mold and the cast piece as a result of the withdrawal from the mold. A shield means is placed to seal-off space between the at least one feed nozzle, and the mold to prevent entry of gas into the continuous casting apparatus and the pressure is reduced in the sealed-off space to thereby eliminate a pressure differential between the pressure in the sealed-off space and the pressure created in the space formed at the connecting point between the break ring, the mold and the cast piece during the intermittent withdrawal from the mold.

Horizontal continuous casting method and apparatus

In a method and apparatus for withdrawing a strand in a horizontal continuous casting installation, the strand is withdrawn from a mold by a predetermined stroke and then retracted by a smaller stroke corresponding to shrinkage of the strand. This cycle of withdrawal and retraction is repeated intermittently. A strand withdrawing and retracting characteristic of a cycle is set in a control unit, and pinch rolls for withdrawing and retracting the strand are controlled based on the set characteristic. Actual withdrawing and retracting strokes of the strand are detected by a detecting device and the detected signal is compared with the set characteristic to produce an instruction signal which is fed back to the pinch rolls, so that the positional accuracy of the strand and the quality of the strand are improved.

Method of and apparatus for withdrawing strand in horizontal continuous

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Hikari, Japan

Hiroshi Iwasaki