Kawasaki Steel Corporation

Kawasaki Seitetsu K.k.

Hisashi Ohmori

Masayuki Ohnishi

Tsutomu Nozaki

Kyoji Nakanishi

Hideshi Ohzu

Jun-ichi Matsuno

Hiromi Ohtani

Yoshiji Yamamoto

Michio Tanaka

Joshiji Yamamoto

Kenichiro Suzuki

Mizuo Maeda

In the operation of a top-and-bottom blown converter, top-blowing oxygen gas is blown such that the center of a hot spot created by the oxygen gas jet from each of the nozzles of a top-blowing multi-nozzle lance is positioned outside a bubbling region of the molten metal surface which rising bubbles of gas from bottom-blowing tuyeres reach.

Method of operation of a top-and-bottom blown converter

A device for separating slag from molten bath to be discharged from a container, for example, a converter, ladle or the like comprising a tortuous molten bath discharge passage communicated with the container and shaped and arranged such that the static pressure of that portion of the molten bath which is remained in the tortuous molten bath discharge passage after the molten bath has been discharged from the container is kept in balance with the static pressure of the slag following the flow of the molten bath.

Device for separating slag from molten bath

The method of sequential continuous-casting of the different grade of steel according to the present invention comprises the steps of: stopping the pouring of a first grade of molten steel into a mold and the drawing of cast slab; immersing a columnar steel stock being circular or polygonal in cross section and equipped with guiding jigs into the substantially center portion of the first grade of molten steel in said mold; forming a solidified phase around said cooling material; and merging said solidified phase in a solidified shell developed from the wall of the mold to form a solidified layer shutting the upper portion off the lower portion of the first grade of molten steel. According to the method, the pouring the second grade of molten steel is started before the solidified layer for shutting the upper portion off the lower portion of the first type of molten steel as described above and the surface of the first grade of molten steel is solidified completely, and at the same time, the drawing of the cast slab is started again and the change-over to the normal continuous casting of the second grade of molten steel is effected.

Method of sequential continuous-casting of different grades of steel

A method of widening the width of a continuously cast strand, especially a cast steel strand, comprising the steps of casting a strand in an adjustable continuous casting mold having a first pair of oppositely situated short sides and a second pair of oppositely situated long sides defining therebetween the mold compartment, wherein at least one of the short sides of the mold can be moved during the casting operation. According to the invention, the short side of the mold, during a first stage, is moved away from the continuously cast strand, by rocking or pivoting the same about its lower end region and is brought out of a starting position into an inclined displaced position, then during a second stage this short side is displaced horizontally, in a direction substantially parallel and away from the cast strand, and then during a third stage such short side is moved away from the strand out of the horizontally displaced position into an end position by pivoting or rocking such short side about its upper end region. The displacement speed which is effective during the second stage is dependent upon the relevant prevailing casting speed and chosen such that there is ensured for contact of the cast metal with the entire, imbued surface of such short side.

Method of enlarging the strand width of a steel strand during continuous

A method of decreasing the width of a continuously cast strand, especially a steel strand, wherein at least one small or narrow side of an adjustable continuous casting mold is displaced during the casting operation. The small side is intermittently moved in the direction of the center or lengthwise axis of the mold at a mean velocity of v'.ltoreq. f .times. S.times. tan .theta., in such a manner that there successively follow one another movement- and standstill time sections each amounting to 1/2f minutes wherein f represents the mold oscillation frequency, S the length of stroke or double amplitude of the mold, and .theta. the taper angle enclosed by the short side of the mold with the vertical.

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Kurashiki, Japan

Hisashi Ohmori