Kobe Steel, Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Research Association for Residual Oil Processing

Kiichi Narita

Takasuke Mori

Kenzo Ayata

Takahiko Fujimoto

Jun Miyazaki

Takamichi Ito

Isao Kobayashi

Minoru Kitamura

Shinichi Inaba

Kenji Mori

Dentaro Kaneko

Masakata Shimizu

Mamoru Taniuchi

Hitoshi Nakata

Yoshifumi Kameoka

Shozo Kawasaki

Akira Egami

Manabu Miyamoto

Nobuo Uemura

Tsuneo Morimitsu

Ryuzo Ijiri

Hiroshi Hara

Nozomu Katagiri

Akitsu Tomita

Masayuki Taniguchi

Kazuyuki Seki

Iwao Matumoto

Tetuo Sato

Yasuo Kanazuka

Masaru Yamaguchi

Toshio Onoye

Kenichi Okimoto

Takehisa Makino

A method for the continuous production of cast steel strands which are 200 mm.times.200 mm or less in cross-section by a continuous casting process in which molten steel containing over 0.20% of carbon is fed into a casting mold with a lubricant through a submerged nozzle or in an open stream and continuously drawn out downwardly of the casting mold, which includes the steps of (a) electromagetically stirring the molten steel at a position within said casting mold by the application of a magnetic field induced by introducing into an electromagnetic coil an alternating current of a frequency (f) in the range of 1.5 to 15 and maintaining the magnetic flux density (gauss) in the range of 602 e.sup.-0.10f to 1844 e.sup.-0.12f at the center of the electromagnetic coil, and (b) electromagnetically stirring the molten steel at a position in the final solidifying zone, of the continuously cast strand, in which the shorter diameter of the molten steel pool is smaller than 1/2 the length of the shorter side of the cast strand, by the application of a magnetic field induced by introduing an alternating current into an electromagnetic coil and maintaining the magnetic flux density (gauss) in the range of 0.143.multidot.D.sup.2 +231 to 0.343.multidot.D.sup.2 +451 at the center of the electromagnetic coil, wherein D is the solidified shell thickness in millimeters of the continuously cast strand, the value of the D ranging from 20 to 90, thereby permitting the production of medium and high carbon killed steel billets, which are improved as to segregations, inclusions, surface quality, cold forgeability, and machinability, by a continuous casting process at low cost.

Method for the continuous production of cast steel strands

A method for the continuous production of cast steel strands which are 200 mm.times.200 mm or less in cross-section by a continuous casting process in which molten steel containing 0.20% or less of carbon is fed into a casting mold with a lubricant through a submerged nozzle or in an open stream and continuously drawn out downwardly of the casting mold. The method includes the steps of (a) electromagnetically stirring the molten steel at a position within said casting mold by the application of a magnetic field induced by introducing into an electromagnetic coil an alternating current of a frequency (f) in the range of 1.5 to 15 hertz and maintaining the magnetic flux density (Gaub) in the range of 602e.sup.-0.10f to 2441e.sup.-0.11f at the center of the electromagnetic coil, and (b) electromagnetically stirring the molten steel at a position in the final solidifying zone, of said continuously cast strand, in which the shorter diameter of the molten steel pool is smaller than 1/2 the length of the shorter side of the cast strand, by the application of a magnetic field induced by introducing an alternating current into an electromagnetic coil and maintaining the magnetic flux density (Gaub) in the range of 0.2.multidot.D.sup.2 +280 to 0.343.multidot.D.sup.2 +451 at the center of the electromagnetic coil, wherein D is the solidified shell thickness in millimeters of said continuously cast strand, the value of D ranging from 20 to 90. The method thereby permits the production of low carbon killed steel billets which are improved as to negative segregations, center cavities, inclusions, surface quality, cold forgeability, and machinability, by a continuous casting process at low cost.

A feed nozzle unit for a horizontal continuous casting process, the feed nozzle unit being disposed in coaxial relation between a tundish nozzle and a mold in a horizontal continuous casting device and including a fixing member of cylindrical form fixedly connected to the mold, the feed nozzle being fixed and connected in coaxial relation to the fixing member at a position inside a connecting side of the tundish nozzle, and the connecting refractory material being fitted in coaxial relation to the fixing member at a position adjacent a connecting side of the mold.

Structure of feed nozzle unit for horizontal continuous casting process

An electromagnetic within-mold stirring method and apparatus wherein electromagnetic stirring is imparted to molten steel passing through a mold, under the following conditions where the maximum flux density (in gauss) of a magnetic field induced by an electro-magnetic coil ranges from 1045.e.sup.-0.16f to 2054.e.sup.-0.12f (f: frequency, 1-15 Hz) and the place of the maximum magnetic flux density is within the range of 350 mm from the junction between the pouring nozzle and the mold in the direction of drawing of the cast-piece.

Electromagnetic within-mold stirring method of horizontal continuous

A continuous steel casting process adapted to produce steel castings of satisfactory quality with less center segregations is described. A molten steel is electromagnetically stirred in at least two of three locations, viz., a casting mold and intermediate and final solidifying zones of a continuously cast strand. In the casting mold, is applied a magnetic field induced by alternate current of a frequency f=1.5.about.10 Hz and having G in the range of 195.times.e.sup.-0.18f .about.1790.times.e.sup.-0.2f at the inner surface of the casting mold. The intermediate solidifying zone employs a magnetic field induced by alternate current of a frequency f=1.5.about.10 Hz and having a magnetic flux density G in the range of 195.times.e.sup.-0.18f .about.1790.times.e.sup.-0.2f at the surface of the strand or a magnetic field induced by alternate current of a frequency f=50.about.60 Hz and having a magnetic flux density G in the range of 0.6.times.10.sup.6 /(D-107).sup.2 .about.1.8.times.10.sup.6 /(D-100).sup.2 (in which D=the thickness of a solidified shell layer of the strand) at the surface of the strand. For electromagnetic stirring in the final solidifying zone, a magnetic field induced by alternate current of a frequency f=1.5.about.10 Hz and having a magnetic flux density in the range of 895.times.e.sup.-0.2f .about.2137.times.e.sup.-0.2f is applied.

Continuous steel casting process

The invention provides a novel process for concurrently carrying out production of reduced iron and thermal cracking of heavy oils in which the reaction of thermal cracking is performed in a fluidized state with the fine iron ore as the fluidized medium and the particles of the iron ore become coated with deposits of the carbonaceous by-product material. The fine iron ore with the carbon deposited thereon is introduced in a fluidized-bed reducing furnace and there reduced into reduced iron by contacting with a reducing gas which is produced in a gas reformer from the cracked gas or the residual oil separated from the products of the thermal cracking. In an improvement of the above process, the gas reformer is operated as a fluidized-bed reactor with the reduced iron as the fluidized medium and acting as the reforming catalyst. The reduced iron partially re-oxidized in the reforming reaction is again reduced to completely reduced iron either by recycling into the fluidized-bed reducing furnace or by introducing into a second fluidized-bed reducing furnace.

Process for the production of reduced iron and thermal cracking of heavy

A method for converter blow end-point control which comprises carrying out waste gas analyses on a continuous or intermittent basis in a final stage of the blow and, based on decarburization rate data (waste gas information) obtained from said waste gas analysis, determining the end-point of the blow where the carbon content of the bath equals a target carbon content. The method is characterized by the use of the decarburization rate equation: ##EQU1## which is a differential equation taking account of the delay time (.tau.) of said waste gas information which is a period of time from the time-point of occurrence of a decarburization reaction in the converter till the time when it is detected as said decarburization rate data, and an equation:

Method for converter blow control

A method for rapidly determining a sulfur level in materials, particularly molten metals or gases, the method comprising contacting a reference electrode made of a specific type of a metal and metal sulfide mixture with a sulfur-containing molten metal or gas serving also as a counter electrode through a sulfide solid electrolyte thereby measuring an electromotive force established between the electrodes. The working temperature of the molten metal or gas is also measured. These parameters measured are used to calculate a sulfur content based on a certain equation. The probe for carrying out the above method is also disclosed, which comprises a reference electrode made of a material having a certain sulfur potential, a mass of a solid electrolyte comprised of CaS and TiS.sub.2, the reference electrode being contacted with a molten metal or gas through the solid mass to form a cell, a means for measuring an electromotive force generated across the cell, and a means for measuring a working temperature of the molten metal or gas.

Method and probe for the rapid determination of sulfur level

A method for estimating the geographical distribution of a cohesive zone in a blast furnace which is intermittently charged with an iron ore material to produce molten iron substantially in a continuous manner is disclosed. The method comprises altering the whole or part of the composition of the charging iron ore material at a certain time point, measuring variations in the composition of produced molten iron ore slag over a given time period, and estimating the shape of the cohesive zone in the furnace on the basis of a pattern of variation of one selected component and the speed of gravitational descent of the charged material through the furnace.

Method for estimating geographical distribution of cohesive zone in

A method for treating molten steel utilizing an induction coil, a ladle, a treating vessel and at least one passage pipe interconnecting the ladle and the treating vessel which includes the steps of lifting up a part of the molten steel from the ladle to the treating vessel disposed over the ladle through adjustment of molten steel composition and/or degassing in the treating vessel, thereafter returning the molten steel to the ladle through the at least one passage pipe, circulating or reciprocating the molten steel between the ladle and the treating vessel while heating the molten steel by the induction coil disposed around the at least one passage pipe and operating the linear motor at a frequency of 50 to 60 cycles.

Method for treating molten steel and apparatus therefor

A method of agitating a bath of melted metal for treating the same by blowing gas into a one piece columnar body of such melted metal disposed in the bath to cause the apparent specific gravity of the columnar body to be reduced and to thereby be hydrostatically lifted, and returning the lifted portion of the melted metal to the bath by pouring the same with a splashing effect onto the free surface of the bath, in a manner to continuously change the pouring position on the free surface of the bath, thereby causing improved agitation of the bath, and especially improved contact and mixing of the melted metal and a treating agent generally floating on the free surface of the bath.

Method of and an apparatus for agitating a bath of melted metal for

A method of agitating a bath of melted metal for treating the same by blowing gas into a columnar body of such melted metal disposed in the bath to cause the apparent specific gravity of the columnar body to be reduced and to thereby be hydrostatically lifted, and returning the lifted portion of the melted metal to the bath by pouring the same with a splashing effect onto the free surface of the bath, in a manner to continuously change the pouring position on the free surface of the bath, thereby causing improved agitation of the bath, and especially improved contact and mixing of the melted metal and a treating agent generally floating on the free surface of the bath.

Method for agitating a bath of melted metal for treating the same

A sampling device for a quantitative determination of hydrogen in molten metal, which includes a material in which hydrogen is relatively non-diffusible during testing or readily soluble during sampling and a refractory vessel housing this material. This refractory vessel is sealed so as to maintain a vacuum or negative (reduced) pressure therein, and is provided with a thin-walled aspirating portion which is readily destroyed by an external pressure.

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Kobe, Japan

Kiichi Narita