Abstract: A method for containing a slab during continuous casting, including casting a slab along a casting axis, said slab having a predefined width, wherein the method provides a containment of the slab with a plurality of rolls, said rolls being disposed in pairs facing to each other, and defining a passage along the casting axis for the cast slab, wherein the plurality of rolls includes electromagnetic rolls provided with an electromagnetic stirrer which stirs the liquid contained in the slab.

Abstract: A system is disclosed which includes a chamber, one or more transmitters configured to emit EM radiation, one or more power harvesters, one or more EM stirrer, and a processing system configured to a) receive a measure of dimensional characteristics of the chamber b) control the one or more EM stirrers, c) evaluate statistical properties of the statistical EM environment, d) set a new criterion for acceptable statistical properties of the statistical EM environment, e) measure a lowest usable frequency of the chamber below which the statistical properties are not acceptable according to a predetermined criterion, f) determine an efficiency profile of the one or more power harvesters versus frequency, g) select an operating frequency that maximizes efficiencies of the one or more power harvesters, h) measure a collective efficiency of the chamber, and i) return to step d if the measured collective efficiency is below a predetermined efficiency threshold.

Abstract: This electromagnetic stirring device configured to apply an electromagnetic force which generates a swirling flow around a vertical axis to molten metal in a mold by generating a rotating magnetic field in the mold, which is a quadrangular tubular mold for continuous casting, the electromagnetic stirring device provided with an iron core enclosing the mold at a side of the mold and including two teeth arranged side by side in a circumferential direction of the mold so as to face an outer side surface for each of outer side surfaces of the mold, coils wound around the respective teeth of the iron core, and a power supply device which applies an alternating current to each of the coils with a phase shift by 90° in arrangement order of the coils so as to generate the rotating magnetic field.

Abstract: The high-strength seamless steel pipe has a volume fraction of tempered martensite of 95% or more, and a prior austenite size number of 8.5 or more, and contains nitride inclusions having a size of 4 ?m or more and whose number is 100 or less per 100 mm2, nitride inclusions having a size of less than 4 ?m and whose number is 700 or less per 100 mm2, oxide inclusions having a size of 4 ?m or more and whose number is 60 or less per 100 mm2, and oxide inclusions having a size of less than 4 ?m and whose number is 500 or less per 100 mm2, in a cross section perpendicular to a rolling direction.

Abstract: In continuous casting, to provide products with excellent quality with high productivity. A molten metal from a melting furnace is stirred and driven by a Lorentz force due to crossing of magnetic lines of force from a magnet and direct current and sent to a mold while improving the quality of the molten metal, or a molten metal immediately before solidification in the mold by the Lorentz force to equalize the temperature of the molten metal immediately before solidification in the mold. As a result, finally a high quality product can be obtained, and the performance of the magnet can be maintained by cooling the magnet.

Abstract: This present disclosure describes a system and process for laminating a planar film sheet onto a curved surface of an optical element. One or more cuts to a planar film sheet are determined based in part on a curved surface of an optical element. The planar film sheet is cut along the determined one or more cuts to the planar film sheet to form a lamination sample. And the lamination sample has a plurality of stress relief boundaries that correspond to the determined one or more cuts to the planar film sheet. The lamination sample is laminated to the curved surface of the optical element to form a laminated coating on the optical element. And adjacent stress relief boundaries of the plurality of stress relief boundaries are in contact with each other, such that the laminated coating is a continuous film across the curved surface.

Abstract: A method of stirring and apparatus for stirring using electromagnetic stirrer units is provided. The method and apparatus are particularly useful in relation to molten metal stirring. Each stirrer unit is mounted on a moveable carriage so that it can be moved between a first location, a second location and potentially further locations. The same stirrer unit is used to provide stirring at each location, so allowing multiple locations to be stirred but only requiring a single stirrer unit to do so. The method and apparatus also provide convenient connection of air cooling to the stirrer unit.

Abstract: An apparatus for continuous casting of molten material includes an elongate tube of electrically conductive material having an inner and an outer wall defining a molding cavity therein, the inner and outer walls having a first end having an inlet for receiving the molten material and a second end having an outlet for removing a solidifying billet formed from the molten material; an electrical coil with inner and outer surfaces, the electrical coil arranged to surround the outer wall of the elongate tube; and an annular channel defined by the outer wall of the elongate tube and the inner surface of the electrical coil. When pulsating current passes through the electrical coil, a counter current is induced in the elongate mold causing a repelling force between the electrical coil and the elongate mold, thereby causing inward radial flexure of the elongate mold.

Abstract: An assembly for a metal-making process, having: a tundish, a submerged entry nozzle (SEN) configured to provide tapping of molten metal from the tundish, and an electromagnetic stirrer arranged around the SEN, the electromagnetic stirrer having a closed and integral SEN-enclosing portion provided with coils for generating a rotating electromagnetic field in the SEN, the SEN-enclosing portion providing a circumferentially closed and integral annular passage through which the SEN extends, wherein the electromagnetic stirrer is immovably mounted relative to the tundish and relative to the SEN.

Abstract: Production plant of metal rods, casting machine, casting process and control method of at least three electromagnetic stirrer devices, wherein one provides at least one phase of switching between two operating configurations of the electromagnetic stirrer devices of which a first operating configuration with the generation of a rotating electromagnetic field inducing in the metallic material in the molten state a rotational motion and a second operating configuration with the generation of a linear electromagnetic field inducing in the metallic material in the molten state a linear motion.

Abstract: A method for continuous casting of thin slabs may involve feeding a molten metal into a mold, molding a partially solidified thin-slab strand from the molten metal in the mold, reducing a flow rate of the molten metal in the partially solidified thin-slab strand by way of an electromagnetic brake positioned in a region of the mold, and removing the partially solidified thin-slab strand from the mold by way of a strand guiding system. Unsolidified parts of the partially solidified thin-slab strand may be stirred by an electromagnetic stirrer arranged underneath the mold downstream along a strand takeoff direction of the thin-slab strand. Further, a traveling electromagnetic field may be produced by the electromagnetic stirrer in a region of the thin-slab strand that is at a distance from the mold of between 20 and 7000 millimeters along the strand takeoff direction.

Abstract: Methods and apparatus for moving a molten metal are provided in which the electromagnetic inductor includes at least two pairs of electromagnetic pole pairs and in which a first magnetic field component is generated between one pole in a first electromagnetic pole pair and a second pole in a different electromagnetic pole pair, and in which a second magnetic field component is generated between the two poles in one or more electromagnetic pole pairs, the second magnetic field component thereby generating one or more eddy currents in the molten metal. Those eddy currents are generally parallel to the surface of the molten metal and so have greater magnitude and extent that eddy currents perpendicular to the surface. Such eddy currents provide useful additional movement to the molten metal, for instance for stirring purposes, particularly when the depth of molten metal is small.

Abstract: A method and device for producing motor vehicle chassis parts is provided. The motor vehicle chassis parts can be subjected to tensile stress, compressive stress and torsion and the mechanical strength of the motor vehicle chassis parts can be adjusted over the respective cross-section. The motor vehicle chassis parts have high ductility and temperature stability and are made of an AlSiZnMg alloy by permanent mould casting.

Abstract: An arrangement for a continuous casting process. The arrangement includes a vessel having a first opening for receiving molten metal in the vessel, a second opening for discharging the molten metal from the vessel, and a body extending between the first opening and the second opening, a first magnetic arrangement attached to the body, the first magnetic arrangement having a magnetic core with legs, and coils arranged around the legs, and a power system configured to provide an alternating current superimposed on a carrier current to each of the coils, each pair of alternating current and carrier current provided to a coil forming a flow control current, wherein flow control currents provided to adjacent coils are phase shifted relative each other, thereby creating a travelling magnetic field in molten metal in the vessel. A corresponding method is also presented herein.

Abstract: An arrangement for a continuous casting process. The arrangement includes a vessel having a first opening for receiving molten metal in the vessel, a second opening for discharging the molten metal from the vessel, and a body extending between the first opening and the second opening, a first magnetic arrangement attached to the body, the first magnetic arrangement having a magnetic core with legs, and coils arranged around the legs, and a power system configured to provide an alternating current superimposed on a carrier current to each of the coils, each pair of alternating current and carrier current provided to a coil forming a flow control current, wherein flow control currents provided to adjacent coils are phase shifted relative each other, thereby creating a travelling magnetic field in molten metal in the vessel. A corresponding method is also presented herein.

Abstract: The present invention discloses a method for producing an aluminum-zirconium-titanium-carbon (Al—Zr—Ti—C) intermediate alloy; the Al—Zr—Ti—C intermediate alloy comprises 0.01% to 10% Zr, 0.01% to 10% Ti, 0.01% to 0.3% C, and Al in balance; the producing method comprising the steps of: preparing commercially pure aluminum, zirconium, titanium, and graphite material according to the weight percentages of the aluminum-zirconium-titanium-carbon intermediate alloy; the graphite powder is subjected to the following treatments: being added to the aqueous solution of KF, NaF, K2ZrF6, K2TiF6 or the combination thereof, soaked for 12 to 72 hours, filtrated or centrifuged, and dried at 80° C. to 200° C. for 12 to 24 hours; melting the commercially pure aluminum and keeping it at 700° C. to 900° C. to provide aluminum liquid, in which the prepared zirconium, the titanium and the treated graphite powder are added and melted to provide an alloy solution; and keeping the alloys solution at 700° C. to 900° C.

Abstract: The present invention discloses a method for producing an aluminum-zirconium-carbon (Al—Zr—C) intermediate alloy; the Al—Zr—C intermediate alloy has a chemical composition of 0.01% to 10% Zr, 0.01% to 0.3% C, and Al in balance; the producing method comprising the steps of: producing commercially pure aluminum, zirconium metal, and graphite material according to the weight percentages of the aluminum-zirconium-carbon intermediate alloy; the graphite is graphite powder having an average particle size of 0.074 mm to 1 mm; and the graphite powder is subjected to the following treatments: being added to the aqueous solution of KF, NaF, K2ZrF6, K2TiF6 or the combination thereof, soaked for 12 to 72 hours, filtrated or centrifuged, and dried at 80° C. to 200° C. for 12 to 24 hours; melting the commercially pure aluminum and keeping it at 700° C. to 900° C.

Abstract: In a method for continuously casting an extremely low carbon steel using a continuous casting machine, by adjusting the chemical components of extremely low carbon steel within a specified range by taking into account an interface tension gradient in a concentration boundary layer on a front surface of a solidified shell, and also by optimizing intensities of the DC magnetic fields applied to the upper magnetic poles and the lower magnetic poles respectively corresponding to a slab width of a slab to be casted and a casting speed, it is possible to acquire the slab having high quality not only with the small number of defects caused by the entrainment of bubbles, non-metallic inclusion and a mold flux into the molten steel.

Abstract: A continuous casting device for steel of the present invention includes a casting mold for casting a molten steel, a submerged entry nozzle, an electromagnetic stirring device, and an electromagnetic brake device. Further, a curved portion which is curved toward the electromagnetic stirring device is formed at least at a position where the curved portion faces the submerged entry nozzle, on each of the long side walls. Moreover, the horizontal distance between a top of the curved portion and the submerged entry nozzle in plan view is equal to or more than 35 mm and less than 50 mm.

Abstract: A steel continuous casting method using a continuous caster that includes a pair of upper magnetic poles and a pair of lower magnetic poles is disclosed. The method comprises braking a molten steel flow with DC magnetic fields respectively applied to a pair of upper magnetic poles and a pair of lower magnetic poles while stirring the molten steel with an AC magnetic field simultaneously applied to the pair of upper magnetic poles, the strength of an AC magnetic field applied to the upper magnetic poles and strengths of DC magnetic fields applied to the upper magnetic poles and the lower magnetic poles are controlled within a particular ranges in accordance with the width of a slab to be cast.

Abstract: A steel continuous casting method using a continuous caster that includes a pair of upper magnetic poles and a pair of lower magnetic poles is disclosed. The method comprises braking a molten steel flow with the DC magnetic fields respectively applied to the pair of upper magnetic poles and the pair of lower magnetic poles while stirring a molten steel with an AC magnetic field simultaneously applied to the pair of upper magnetic poles, the strength of an AC magnetic field applied to the upper magnetic poles is set within the range of 0.060 to 0.090 T and the strengths of DC magnetic fields applied to the upper and lower magnetic poles are controlled within particular ranges in accordance with the width of the slab to be cast and the casting speed.

Abstract: A split stirring roll including two half-rolls aligned at a distance from one another, each incorporating a polyphase linear inductor mounted fixedly a short distance from outer tubular bodies of each half-roll to arrange between them an annular space for circulation of a cooling fluid; each inductor can generate a traveling magnetic field sliding along the width of a cast slab. The two half-rolls are mounted externally in end rolling bearings and internally in a common intermediate rolling bearing attached between them, the inductors including narrowed-diameter hollow terminal portions to rest in the three rolling bearings and communicate with a cooling circuit including the annular spaces. The split stirring roll is configured for continuous casting of extra-wide slabs and can form a preferred tool for controlled electromagnetic stirring of molten metal for optimized exchange of material between a top and bottom of a casting machine.

Abstract: A continuous casting device includes a mould, a nozzle, and an electromagnetic stirrer provided around the nozzle above the mould, the stirrer including a core of a magnetic material that extends circumferentially around the nozzle and a plurality of windings wound around the core. The windings are wound around a cross section of the core as seen in the circumferential direction of the core.

Abstract: A steel continuous casting method using a continuous caster that includes a pair of upper magnetic poles and a pair of lower magnetic poles is disclosed. The method comprises braking a molten steel flow with DC magnetic fields respectively applied to a pair of upper magnetic poles and a pair of lower magnetic poles while stirring the molten steel with an AC magnetic field simultaneously applied to the pair of upper magnetic poles, the strength of an AC magnetic field applied to the upper magnetic poles and strengths of DC magnetic fields applied to the upper magnetic poles and the lower magnetic poles are controlled within a particular ranges in accordance with the width of a slab to be cast.

Abstract: The invention relates to a manufacturing method for making an unwrought semi-finished product having at mid thickness a density of micropores of size greater than 90 ?m less than 50% and preferably less than 20% of the density of micropores of size greater than 90 ?m obtained by a method according to prior art. The method according to the invention comprises in particular an ultrasound treatment step for the molten metal bath in a furnace and/or a vessel using an immersed device comprising at least one ultrasound transmitter. The semi-finished products obtained according to the method of the invention are particularly advantageous for manufacturing by rolling sheets designed for the aircraft industry to produce spars, ribs, upper and lower wing skins and for manufacturing by extrusion sections designed for the aircraft industry to produce stiffeners.

Abstract: A steel continuous casting method using a continuous caster that includes a pair of upper magnetic poles and a pair of lower magnetic poles is disclosed. The method comprises braking a molten steel flow with the DC magnetic fields respectively applied to the pair of upper magnetic poles and the pair of lower magnetic poles while stirring a molten steel with an AC magnetic field simultaneously applied to the pair of upper magnetic poles, the strength of an AC magnetic field applied to the upper magnetic poles is set within the range of 0.060 to 0.090 T and the strengths of DC magnetic fields applied to the upper and lower magnetic poles are controlled within particular ranges in accordance with the width of the slab to be cast and the casting speed.

Abstract: Provided is a continuous cast slab and a manufacturing method for the same, wherein solidified layers of a cast slab having a non-solidified layer are compressed with each other during a continuous casting process to fundamentally prevent occurrence of defects, such as center segregation or porosity, which deteriorate quality of the cast slab, thereby decreasing defects. A continuous casting method for producing a cast slab by drawing molten steel from a mold includes preparing a compressing unit, and reducing at least one side of the drawn cast slab by using the compressing unit, wherein solute-enriched residual molten steel is caused to flow back in a direction opposite to a casting direction. Thus, it is possible to produce a cast slab wherein defects such as center segregation are greatly eliminated.

Abstract: A method for casting of metal. A mold is provided including two broad sides and two narrow sides. A molten metal is introduced into the mold. There is a meniscus at a top of the molten metal. Additional molten metal is supplied into the molten metal via a casting tube below the meniscus. At least one stirrer including an iron core and a coil applied around the iron core is arranged around the mold. A length of the iron core in relation to a length of the broad side of the mold is between 50% and 80% of the length of the broad side. An upper part of the iron core is positioned from 50 mm above to 195 mm below the surface of the meniscus. A magnetic field is applied to the molten metal with the at least one stirrer to stir the molten metal.

Abstract: A continuous casting method of molten metal using electromagnetic force to improve the cast slab surface properties and reduce the nonmetallic inclusions and bubbles trapped inside the cast slab is provided. An alternating current is run through an electromagnetic coil arranged around a casting mold so as to surround a casting space to control the meniscus shape to improve the cast slab surface properties. The discharge ports of a submerged entry nozzle are oriented upward and the direction of the discharge flow from the discharge ports is above the intersection of the casting mold short side and meniscus.

Abstract: An electromagnetic stirrer for stirring molten steel of the liquid core in a width-wise direction of the slab includes an iron core disposed with its length-wise axis along a width-wise direction of slab, and a plurality of exciting coils wound around the outer circumference of and about a length-wise axis of the iron core, wherein two-phase or three-phase alternating current is passed through the coils. The phases of the current in the exciting coils are distributed to impart a stirring flow to the molten that includes flow from the minor sides to the center of the slab or from one minor side to the other minor side with a reversing flow at predetermined time intervals.

Abstract: In a high-tensile steel plate according to the invention, the carbon equivalent Pcm represented in Expression (1) is from 0.180% to 0.220%, the surface hardness is a Vicker's hardness of 285 or less, the ratio of a Martensite Austenite constituent in the surface layer is not more than 10%, the ratio of a mixed structure of ferrite and bainite inside beyond the surface layer is not less than 90%, the ratio of the bainite in the mixed structure is not less than 10%, the thickness of the lath of bainite is not more than 1 ?m, the length of the lath is not more than 20 ?m, and the segregation ratio as the ratio of the Mn concentration in the center segregation part relative to the Mn concentration at a part in a depth equal to ¼ of the thickness of the plate from the surface is not more than 1.3. Pcm=C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5B . . . (1) where the element symbols in Expression (1) represent the % by mass of the respective elements.

Abstract: Four distinct polyphased inductors for a travelling magnetic field and mounted with two inductors per large side on the large sides of the ingot mold, the inductors placed side by side on a same large side of the ingot mold and producing driving forces that push the molten metal, along the width of the ingot mold, both in the same direction, which is a direction opposite to that of the driving forces produced by the two inductors placed opposite on the other large side.

Abstract: A continuous casting device, including a mould, an electromagnetic device arranged outside the mould and arranged to provide an electromagnetic field acting on a melt in the mould, the electromagnetic device being supplied with electric current includes a base frequency and harmonics, and thereby providing a first electromagnetic field based on the base frequency and a second electromagnetic field based on the harmonics, and an inductive sensor, arranged at the mould for the purpose of sensing the position of a meniscus of the melt, and operating at frequencies corresponding to the harmonics. The continuous casting device includes at least one screen between the electromagnetic device and the sensor, and the screen is arranged so as to prevent the second electromagnetic field from disturbing the operation of the sensor but to permit the first electromagnetic field to act on the melt in the region of the meniscus.

Abstract: A method of continuously casting molten steel to produce high surface quality slab by preventing depressions and cracking. The steel is high Al steel having an Al content of 0.1% or more. High-Al molten steel is continuously cast using mold powder containing T—CaO (T—CaO presumes total Ca converted to CaO): 35 to 55%, SiO2: 10 to 30%, Al2O3: 4.0% or less (excluding 0%), MgO: 0.2 to 1.0%, Li2O: 7 to 13%, F: 7 to 13%, C: 10.5 to 14%, and inevitable impurities; and satisfying: 1.6?[T—CaO]/[SiO2]?5 and 0.2?[Li2O]/[SiO2]?1.1. The method is performed by controlling the molten steel surface level fluctuation speed in the mold; the pouring angle of the molten steel in the width direction of the mold; the stroke in the amplitude; and the negative strip time tN as defined.

Abstract: In a method and apparatus for the continuous casting of preliminary steel sections, the liquid or molten steel is introduced substantially vertically into an open-ended die. The cross section of the cavity of the die is made up of a web part and one or more flange parts, for example, such as in preliminary double-T sections. The liquid core of the strand of the preliminary section is set in agitating motions transversely to the direction of continuous casting by selectively using electromagnetically-induced forces in the regions of the flange parts and/or of the web part. The agitating motions have the effect of exchanging the liquid steel in the molten crater of the strand of the preliminary section in and between flange parts and the web part.

Abstract: The present invention provides a previously unattainable compact and high thrust electromagnetic stirrer coil, that is, an electromagnetic stirrer coil for stirring molten steel in a mold by electromagnetic force, in which electromagnetic stirrer coil a space factor of the yoke sectional area (?) with respect to an inside area in a vertical cross-section of said electromagnetic stirrer coil is 0.5 to 0.9 and a yoke width B is 100 mm to 300 mm. Preferably, a magnetomotive force F of said electromagnetic stirrer coil divided by the yoke width B, that is, a value of F/B, is 800 kAT/m or more.

Abstract: The present invention provides a low carbon steel sheet and a low carbon steel slab on which formation of surface defects can be surely prevented by preventing aggregation of inclusions in the molten steel and finely dispersing inclusions in the steel sheet or slab, and a process for producing the steel sheet and slab. The present invention provides a process comprising the steps of decarburizing a molten steel so as to produce a carbon concentration of up to 0.01% by mass, pre-deoxidizing the molten steel by adding Al thereto so as to produce a dissolved oxygen concentration from 0.01 to 0.04% by mass, adding thereto Ti and at least La and/or Ce, and casting the molten steel, and a steel sheet and a steel slab obtained by the process.

Abstract: Disclosed is a continuous casting in which an electromagnetic stirrer is installed upstream, in the casting direction, of the reduction rolling position of a slab, and in which a slab with a liquid core is reduced in thickness, wherein by imparting a collision flow forming-type stirring and a uni-directional alternating flow forming-type stirring, molten steel with concentrated segregation elements is stirred and diffused in a width-wise direction of slab, whereby a slab stabilized in center segregation qualities can be produced over long-time casting operation. Since the stirring flowing pattern is selectively imparted by means of the same electromagnetic stirrer, it is effective to decrease facility and equipment costs, improve maintainability, and extensively cope with various casting conditions.

Abstract: A process for continuous casting of slabs or other metal products of elongate cross section, for example made of steel, in which a molten metal is poured into a cooled mold, and the externally solidified product is continuously extracted from the mold and guided in a secondary cooling zone downstream of the mold. To obtain a cast product exhibiting predominantly equiaxed solidification, the product extracted from the mold is subjected to electromagnetic stirring in segment zero of the secondary cooling zone by at least two stirrer-rolls incorporated into the segment zero.

Abstract: Method for controlling a flow of molten steel in a mould by applying at least one magnetic field to the molten steel in a continuous slab casting machine. Controlling a molten steel flow velocity on a molten steel bath surface to a predetermined molten steel flow velocity by applying a static magnetic field to impart a stabilizing and braking force to a discharge flow from an immersion nozzle when the molten steel flow velocity on the meniscus is higher than a mould powder entrainment critical flow velocity. Controlling the molten steel flow velocity on the meniscus to a range of from an inclusion adherence critical flow velocity or more to a mould powder entrainment critical flow velocity or less by applying a shifting magnetic field to increase the molten steel flow when the molten steel flow velocity on the meniscus is lower than the inclusion-adherence critical flow velocity.

Abstract: In the continuous casting of flat metal products with a submerged nozzle having lateral outlets, a mold is equipped on each of its long sides with a pair of linear inductors that generate a magnetic field that travels horizontally over a width of the long sides and are placed on sides of the nozzle. The inductors are mounted in pairs to slide vertically over the height of the mold, and by being moved, pass from a low stirring position, located level with the outlets of the nozzle, to a high stirring position, located level with a meniscus of the liquid metal in the mold, and vice versa. Also, on passing from one position to the other, the connections for the inductors to the phases of the power supply are modified to reverse the direction of travel of the magnetic field of only one of the two inductors of each pair.

Abstract: The invention provides a method of continuous casting for producing a slab excellent in surface quality by preventing formation of depressions and occurrence of cracking of a slab even in the case of producing a high Al steel having an Al content of 0.1% or more by continuous casting. At the time of continuous casting of a high-Al molten steel containing prescribed chemical components by using a mold powder, a powder containing T—CaO: 35 to 55%, SiO2: 10 to 30%, Al2O3: 4.0% or less (excluding 0%), MgO: 0.2 to 1.0%, Li2O: 7 to 13%, F: 7 to 13%, C: 10.5 to 14%, and inevitable impurities and satisfying 1.6?[T—CaO]/[SiO2]?5 and 0.2?[Li2O]/[SiO2]?1.1 is used as the mold powder, and operation is carried out while controlling the conditions such as the molten steel surface level fluctuation speed in the mold; the pouring angle of the molten steel in the width direction of the mold; the stroke in the amplitude; and the negative strip time tN defined by a prescribed relational expression.

Abstract: Disclosed is a continuous casting in which an electromagnetic stirrer is installed upstream, in the casting direction, of the reduction rolling position of a slab, and in which a slab with a liquid core is reduced in thickness, wherein by imparting a collision flow forming-type stirring and a uni-directional alternating flow forming-type stirring, molten steel with concentrated segregation elements is stirred and diffused in a width-wise direction of slab, whereby a slab stabilized in center segregation qualities can be produced over long-time casting operation. Since the stirring flowing pattern is selectively imparted by means of the same electromagnetic stirrer, it is effective to decrease facility and equipment costs, improve maintainability, and extensively cope with various casting conditions.

Abstract: The present invention relates to a continuous cast slab and a manufacturing method for the same, wherein solidified layers of a cast slab having a non-solidified layer are compressed with each other during a continuous casting process to fundamentally prevent occurrence of defects, such as center segregation or porosity, which deteriorate quality of the cast slab, thereby decreasing defects. A continuous casting method for producing a cast slab by drawing molten steel from a mold includes preparing a compressing unit, and reducing at least one side of the drawn cast slab by means of the compressing unit, wherein solute-enriched residual molten steel is caused to flow back in a direction opposite to a casting direction. Thus, it is possible to produce a cast slab wherein defects such as center segregation are greatly eliminated.

Abstract: Four distinct polyphased inductors (10a, 10b, 10c, 10d) for a travelling magnetic field and mounted with two inductors per large side (12, 12?) on the large sides of the ingot mould, the inductors (10a, 10b) placed side by side on a same large side (12) of the ingot mould and producing driving forces that push the molten metal, along the width of the ingot mould, both in the same direction, which is a direction opposite to that of the driving forces produced by the two inductors (10c, 10d) placed opposite on the other large side (12?), the intensity of the driving forces are adjusted in a differential manner between them such that in proximity to a large side, if there the flow of the metal is higher “towards the interior” than “towards the exterior”, greater intensities are applied to the two forces that push the metal “towards the exterior”, and conversely, if said flow is less strong “towards the interior” than “towards the exterior”, greater forces are applied to the forces that push the metal “towards th

Abstract: The present invention provides a continuous casting method of steel preventing alumina and other nonmetallic inclusions becoming causes of slivers and argon bubbles becoming causes of blowholes from being entrained and thereby enabling the production of a cast slab superior in surface and internal quality, that is, one giving an inside bore 21 of an immersion nozzle 21 a horizontal sectional shape of an elliptical shape or oblong shape with a length ratio DL/DS of that long axis DL and short axis DS of 1.2 to 3.8, making a direction of that long axis substantially parallel to a long side direction of the casting mold 3, and making the sliding direction of the sliding nozzle 1 a direction perpendicular to said long axis to supply the molten steel in the casting mold 3. Note that a ratio S1/S0 of a sectional area S1 at a smallest sectional area part 23 of the inside bore 21 and a sectional area S0 of a nozzle hole 11 of the sliding nozzle 1 is made 0.5 to 0.

Abstract: A method for controlling a flow of molten steel in a slab continuous casting machine including controlling a molten steel flow velocity on a molten steel bath surface to a predetermined flow velocity by applying a shifting magnetic field; controlling the molten steel flow velocity on the molten steel bath surface from an inclusion-adherence critical flow velocity or more to a mold-powder entrainment critical flow velocity or less by applying a shifting magnetic field; and controlling the molten steel flow velocity on the molten steel bath surface from the inclusion-adherence critical flow velocity or more to the mold-powder entrainment critical flow velocity or less by applying a shifting magnetic field.

Abstract: A method and an apparatus are provided for electromagnetic stirring during a continuous casting process, especially for casting a billet and bloom of medium and high carbon steels. The method and apparatus provide a higher surface quality of the ingot, reduce the entrapping of nonmetallic inclusions into the ingot, and suppress issues regarding central segregation and central porosity. The method provides an improvement in the stirring process from the meniscus to the crater end—and relates to in-mold stirring and stirring in a zone of secondary cooling and up to the crater end. The in-mold stirring is geared towards the suppression of meniscus disturbance, for submerged casting, in particular, the reducing of helical and axial velocity components of the molten steel, the lowering of the initial solidification point to avoid the touching of a shell edge with the slag ring, and a decrease of oscillation marks.

Abstract: Apparatus and methods are provided for eliminating axial porosity accompanied by impurity segregation arising at bulk crystallization of the axial zone of the liquid core of a continuous ingot.

Abstract: In a high-tensile steel plate according to the invention, the carbon equivalent Pcm represented in Expression (1) is from 0.180% to 0.220%, the surface hardness is a Vicker's hardness of 285 or less, the ratio of a Martensite Austenite constituent in the surface layer is not more than 10%, the ratio of a mixed structure of ferrite and bainite inside beyond the surface layer is not less than 90%, the ratio of the bainite in the mixed structure is not less than 10%, the thickness of the lath of bainite is not more than 1 ?m, the length of the lath is not more than 20 ?m, and the segregation ratio as the ratio of the Mn concentration in the center segregation part relative to the Mn concentration at a part in a depth equal to ¼ of the thickness of the plate from the surface is not more than 1.3. Pcm=C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5B . . . (1) where the element symbols in Expression (1) represent the % by mass of the respective elements.