Kawasaki Steel Corporation

Sumitomo Heavy Industries, Ltd.

Kenichi Sorimachi

Hirokazu Tozawa

Toshikazu Sakuraya

Shuji Takeuchi

Seiji Itoyama

Tetsuya Fujii

Seiji Nabeshima

Yuji Miki

Hakaru Nakato

Hidenari Kitaoka

Yoshiei Kato

Saburo Moriwaki

Akira Yamauchi

Nagayasu Bessho

Tsutomu Nozaki

Yukio Oguchi

Sumio Yamada

Fumio Sudo

Seiji Taguchi

Makoto Aratani

Chikashi Tada

Seiko Nara

Katsutoshi Igawa

Noboru Yasukawa

Kenji Saito

Yoshiro Tomiyama

Katsuo Kinoshita

Haruji Okuda

Mitsuo Saito

Takeshi Shiraishi

Toshiaki Ochi

Yasuhito Itoh

Mitsuru Sakurai

Akira Idogawa

Koji Hosotani

Yoichi Ito

Takashi Matsui

Kouji Hanaoka

Kenji Murata

Hiromitsu Shibata

Shinichi Kaneko

Takahiro Mitumune

Masafumi Maeda

A hot-rolling process prevents surface deterioration of the stainless steel sheet which forms during hot rolling of a stainless steel slab after heating in a heating furnace, and does not cause damage to the heating furnace nor a decrease in yield of the steel sheet. The hot-rolling process for a stainless steel slab includes heating a stainless slab containing 10 weight percent or more of chromium in a heating furnace and hot-rolling the slab. A surface treatment, which is used prior to the heating, composition is composed of a mixture containing at least one of a Ca compound and a Ba compound and a binder for binding the mixture to a slab surface and for forming a coating film on a slab surface.

Process for hot-rolling stainless steel

Method of producing cluster-free Al-killed steel

Titanium killed steel sheets which are not troubled by nozzle clogging while they are produced in a continuous casting process, have few surface defects caused by cluster-type inclusions, and are highly rust resistant, and are formed from a melt of titanium killed steel that contains any one or two of Ca and metals REM in an amount of not smaller than 0.0005% by weight, and wherein the steel contains major oxide inclusions of any one or two of CaO and REM oxides in an amount of from about 5 to 50% by weight, Ti oxides in an amount of not larger than about 90% by weight, and Al.sub.2 O.sub.3 in an amount of not larger than about 70% by weight.

Titanium killed steel sheet and method

Adding aluminum and/or silica to molten steel after decarburization containing about 0.005 percent by weight or less of carbon and about 1.0 percent by weight or less of manganese to form a mildly deoxidized molten steel; adding titanium to the mildly deoxidized molten steel to continue deoxidation so that the molten steel contains about 0.005 percent by weight or less of aluminum, about 0.20 percent by weight or less of silicon and about 0.01 to 0.10 percent by weight of titanium, to form inclusions in the molten steel which essentially consist of a complex oxide of titanium and aluminum, a complex oxide of titanium and silicon, and/or a complex oxide of titanium, aluminum and silicon.

Method of making ultra low-carbon steel

In a method of producing a molten aluminum-killed steel for forming a thin steel sheet, molten steel tapped from a converter is decarburized to a predetermined carbon concentration by using a vacuum degasser, and Al is added to the molten steel in the vacuum degasser to deoxidize the molten steel. A material containing metallic Ca is then added to the molten steel to produce a Ca content of about 0.0005 to 0.005 wt %, and to satisfy [%Ca].times.[%S].ltoreq. about 2.times.1 0.sup.-5. Thereafter, degassing is performed on the molten steel.

Method of producing molten aluminum-killed steel for thin steel sheet

A method of charging coal into a chamber furnace-type coke oven. The coal is fed from a table feeder from a coal hopper so as to be dropped and charged into a carbonization chamber of the coke oven, through a charging cylinder. The coal fed from the table feeder is accelerated by rotation vanes at the initial stage in which the coal starts to drop. The vanes have a rotation center which is located upward on the exterior of a locus of the stream of free fall gravitated by the coal. The rotation speed of the vanes is progressively increased in the latter half of charging of the coal. The coal is thus allowed to accumulate in the carbonization chamber so that the bulk density of the coal in the vertical direction can become uniform. Also disclosed is an apparatus for charging coal into a chamber furnace-type coke oven. The apparatus includes a coal hopper for storing the coal therein. A table feeder feeds the coal from the hopper. Rotation vanes increases the speed of the coal fed from the feeder at the initial stage in which the coal drops from the feeder. The vanes have a rotation center which is located upward on the exterior of a locus of the stream of free fall gravitated by the coal. A charging cylinder guides the coal, which has been accelerated by the vanes and dropped into the carbonization chamber.

Method of charging coal into chamber furnace-type coke oven and

A method of manufacturing steel having Ca including the steps of adding Ca metal or alloy containing Ca to molten steel in a ladle that has been killed by adding a reducing agent, such as Al, to the molten steel in a predetermined quantity when or after the molten steel has been discharged from a converter, subjecting the molten steel to a vacuum degasification process, and supplying the molten steel to a mold through a tundish so that the molten steel is continuously cast, wherein Ca metal or alloy containing Ca is added to the molten steel in the tundish.

Method of manufacturing steel containing Ca

In a process of withdrawing castings while vertically oscillating a mold formed with long side walls and short side walls, the long side walls are moved apart from the castings by operating a hydraulic cylinder in the time zones for which the castings are applied with a large frictional force. On the contrary, the separated long side walls are made to move together to the casting in the other time zones for which the casting is not applied with the large frictional force. By repeating the separation and approaching of the long side walls, it is possible to obtain castings which are reduced in the depths of oscillation marks and suppressed in segregations at oscillation mark trough portions.

Continuous casting process with vertical mold oscillation

One or more streams of molten metal poured into a continuous casting mold are acted on magnetically by static magnetic fields, covering substantially the entire width of the casting mold, thereby reducing the speed of the molten metal streams from the immersion nozzle, unifying the flow profile of the molten metal in the mold, preventing trapping and accumulating of mold powders and inclusions into the cast products. Magnetic poles are provided which are at least as wide as or wider than the minimum width of the cast products and the iron core is arranged on the same face of the casting mold with mutually opposite polarities in the drawing direction. Even if casting conditions change from time to time, defects in final products made of the cast metal are substantially reduced.

Apparatus and method for continuous casting

An apparatus and method for continuous casting steel. A vertical continuous-casting mold consists of a pair of long side frames and a pair of short side frames formed of a metal having low electrical conductivity. An immersion nozzle supplies molten steel to the mold. An induction heating coil surrounded by a backup frame surrounds the vertical continuous-casting mold. The induction heating coil induction-heats the surface of the molten steel and neighboring portions thereof. The apparatus meets the following conditions;

Apparatus and method for continuous casting of steel

A mold powder for use in continuous casting, containing specified amounts of CaO, Al.sub.2 O.sub.3, TiO.sub.2, Li.sub.2 O, BaO, MgO, F and Na.sub.2 O, and further containing at least one of BN and C as aggregate. The mold powder, when used in continuous casting of a steel rich in strong reducing metal elements such as Al, Ti, REM and so forth, remarkably suppresses generation of deterioration in the surface quality of the slab and break out of the slab which are attributable inferior lubrication.

Mold powder for continuous casting

A control device for controlling mold oscillation in a continuous casting machine comprises a horizontal position detector, an open-close control device and hydraulic cylinders. The horizontal position detector is attached to a piston rod of the hydraulic cylinder for detecting an actual position of long-side copper plates of a mold. The open-close control device further comprises a reference position compensation circuit where a predetermined offset value is received. The reference position compensation circuit produces a compensation signal with which a target position of the long-side copper plates is modified. The open-close control device controls the hydraulic cylinders according to the compensation signal such that a deviation between the actual horizontal position and the target horizontal position of the long-side copper plates becomes equal to the offset value.

Control device for controlling mold oscillation in a continuous casting

Steel is continuously cast while adding a mold powder using a vertical continuous casting mold having two pairs of mold surfaces which form a casting cavity, wherein the surface temperature of the mold is kept at 700.degree. C. or more by forming the mold surfaces of a Ni-Cr alloy, and a mold powder having a solidifying point lower than the surface temperature is used so that the mold powder is maintained in a liquid-phase state.

Continuous casting method

A method of removing non-metallic inclusions from a molten metal by allowing the molten metal to pass through at least first and second vessels which are intermediate between a ladle and a mold. The molten metal is made to stay in the vessel for a period not shorter than 40 seconds while a horizontal rotation is imparted to the molten metal in the first vessel. The molten metal is then transferred from the first vessel to the second vessel. The molten metal in the second vessel is then heated. This method is suitably carried out by an apparatus comprising a first vessel having a discharge opening at its bottom and surrounded by a rotational magnetic field generating device for centrifugation of the molten metal in the first vessel, and a second vessel for receiving the molten metal discharged from the first vessel and provided with a heating device for heating the molten metal received therein.

Method of and apparatus for removing non-metallic inclusions in molten

A nozzle for use in continuous casting comprising an inner surface region defining the nozzle port for passing a molten steel, said inner surface region being formed from a mixture having a composition containing 50 to 80 wt % of boron nitride (BN) and 20 to 50 wt % of zirconium oxide (ZrO.sub.2), and a sintering assistant composed of silicon carbide (SiC) and boron carbide (B.sub.4 C) mixed at a weight ratio of 1:1, the sintering assistant being added in amount of 5 to 10 wt parts to 100 wt parts of said mixture. The nozzle is produced by a process comprising the steps of: forming a uniform mixture of fine particles of boron nitride (BN), zirconium oxide (ZrO.sub.2), silicon carbide (SiC) and boron carbide (B.sub.4 C); forming the mixture into a cylindrical blank; and fixing the cylindrical blank in the bore of a nozzle member by means of a joint filling material.

Nozzle for continuous casting and method of producing

Growing community of inventors

Chiba, Japan

Kenichi Sorimachi