Kawasaki Steel Corporation

Jfe Steel Corporation

Kawasaki Steel Corporaton

Kawasaki Limited

Kawasaki Steel Company

Shuji Takeuchi

Kenichi Sorimachi

Yuji Miki

Nagayasu Bessho

Tetsuya Fujii

Toshikazu Sakuraya

Yasuo Kishimoto

Hirokazu Tozawa

Naoki Kikuchi

Seiji Nabeshima

Fumio Sudo

Seiji Itoyama

Shigeru Ogura

Hidenari Kitaoka

Hiroshi Yamane

Mototatsu Sugizawa

Tadasu Kirihara

Yukio Takahashi

Akira Yamauchi

Yoshiei Kato

Yasuhiro Habu

Saburo Moriwaki

Hiroshi Nishikawa

Makoto Aratani

Noboru Yasukawa

Yoshiro Tomiyama

Koji Yamaguchi

Takeshi Shiraishi

Yuki Nabeshima

Hideo Nakamura

Tomomichi Terabatake

Nobuo Harada

Mitsuru Sakurai

Akiharu Takao

Kimiharu Aida

Hisashi Ogawa

Yasuyuki Masumoto

Hiromitu Shibata

During continuous casting of metals, a non-moving, vibrating magnetic field is applied to a molten metal in a casting mold to impose only vibration on the molten metal. This continuous casting method can produce a cast slab much less susceptible to flux entrainment, capture of bubbles and non-metal inclusions near the surface of the molten metal, and surface segregation. The magnetic field is preferably produced by arranging electromagnets in an opposing relation on both sides of the mold to lie side by side in the direction of longitudinal width of the mold, and supplying a single-phase AC current to each coil. The single-phase AC current preferably has frequency of 0.10 to 60 Hz. A static magnetic field can be applied intermittently in the direction of thickness of a cast slab. This technique can produce a cast slab substantially free from the flux entrainment and the surface segregation. Preferably, the static magnetic field is intermittently applied under setting of an on-time t1=0.10 to 30 seconds and an off-time t0=0.10 to 30 seconds. Also, the static magnetic field is preferably applied to the surface of the molten metal.

Method and apparatus for continuous casting of metals

The composition of inclusions and the S concentration in steel are controlled in a manner such that, among the CaO-containing oxide inclusions present in a Ca-containing steel, an equilibrium S soluble amount (% S inc.) of at least 80% of the oxide inclusion particles having a particle diameter of 2 &#x3bc;m or more are about 0.03 wt % or less, thereby inhibiting rust formation due to the inclusions, thus solving a problem which has long been of concern in Ca-containing steels.

Rust-resistant calcium steel

Process for producing high-nitrogen ultralow-carbon steel

During continuous casting of metals, a non-moving, vibrating magnetic field is applied to a molten metal in a casting mold to impose only vibration on the molten metal. This continuous casting method can produce a cast slab much less susceptible to flux entrainment, capture of bubbles and non-metal inclusions near the surface of the molten metal, and surface segregation. The magnetic field is preferably produced by arranging electromagnets in an opposing relation on both sides of the mold to lie side by side in the direction of longitudinal width of the mold, and supplying a single-phase AC current to each coil. The single-phase AC current preferably has frequency of 0.10 to 60 Hz. A static magnetic field can be applied intermittently in the direction of thickness of a cast slab. This technique can produce a cast slab substantially free from the flux entrainment and the surface segregation. Preferably, the static magnetic field is intermittently applied under setting of an on-time t1&equals;0.10 to 30 seconds and an off-time t0&equals;0.10 to 30 seconds. Also, the static magnetic field is preferably applied to the surface of the molten metal.

Production method for continuous casting cast billet

Desulfurization is carried out by blowing CaO into molten iron, and a gas mixture of an inert gas and a hydrocarbon gas is used as a carrier. The ratio of the hydrocarbon gas to the desulfurizing agent is maintained in the range of from about 2.0 to about 50 Nl/kg. This desulfurizing method improves the desulfurization efficiency of the desulfurizing agent, increases the productivity of the desulfurizing process, and reduces the amount of slag generated in the desulfurizing process. Alternatively, a desulfurizing flux is blown into the molten iron together with a carrier gas comprising a gas mixture of an inert gas and a hydrocarbon gas or an inert gas alone at the start of desulfurization. The hydrocarbon gas in the carrier gas is increased, is added, or the unit gas is replaced by the hydrocarbon gas at adequate timing, whereby the desulfurization efficiency is improved.

Method of desulfurizing molten iron

A process for desulfurizing a molten iron alloy in which a desulfurizing agent is applied to the molten iron alloy under agitation. Concurrently, a gas containing a hydrocarbon gas is blown onto the bath surface of the molten iron alloy, or a substance generating a hydrocarbon gas is added to the bath surface.

Method of desulfurizing molten iron alloy

Process for smelting reduction of chromium ore

A method of charging an iron scrap melting cupola with iron scrap and coke enables the iron scrap to be melted with high energy efficiency. The charging pipe feed is set at a level 'h' which meets the condition of h .ltoreq. (r-r') tan .theta., and iron scrap of a quantity Ws meeting the condition of Ws .ltoreq. 1/3.multidot..pi.r.sup.3 .multidot.tan .theta..multidot..rho..sub.s is charged through the charging pipe, followed by charging of coke, wherein h represents the height of the charging feed above the material in the cupola (meters), r represents the inside radius of the cupola (meters), r' represents the inside radius of the charging pipe (meters), .theta. represents the angle of repose of the iron scrap (degrees), Ws represents the quantity of iron scrap per cycle (kg/ch), and .rho..sub.s represents the bulk specific gravity of the iron scrap (kg/m.sup.3).

Method of charging materials into cupola

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

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 method of removing non-metallic inclusions from a molten metal comprises the step of simultaneously applying both a horizontal rotation of the molten metal and heating of the molten metal by induction heating. After the simultaneous application of rotational force and heat, the induction heating may be stopped while the horizontal flow of the molten metal is maintained, so as to promote the separation of the particles of the inclusions. The method is carried out by using an apparatus which has a vessel which contains the molten metal, a rotary magnetic field generating device surrounding the vessel, and an induction heating device also surrounding the vessel. Each of the rotary magnetic field generating device and the induction heating device may be divided into a plurality of circumferential segments and arranged such that the segments of both devices are alternately disposed around the vessel.

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

A process for producing an extremely low carbon steel in a top- and bottom-blown converter. The process is characterized in top-blowing a mixed gas of oxygen gas and an inert gas onto a molten steel in the top- and bottom-blown converter. The mixed gas is blown through a top-blowing lance at the final decarburization stage, while a gas (selected from a group consisting of an inert gas, oxygen gas and a mixture of oxygen and an inert gas) is bottom-blown into the molten steel in the converter.

Steelmaking of an extremely low carbon steel in a converter

Growing community of inventors

Chiba, Japan

Shuji Takeuchi