EP3597328B1 - Continuous casting method for steel - Google Patents

Continuous casting method for steel Download PDF

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Publication number
EP3597328B1
EP3597328B1 EP17906929.9A EP17906929A EP3597328B1 EP 3597328 B1 EP3597328 B1 EP 3597328B1 EP 17906929 A EP17906929 A EP 17906929A EP 3597328 B1 EP3597328 B1 EP 3597328B1
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Prior art keywords
mold
magnetic field
molten steel
less
location
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German (de)
English (en)
French (fr)
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EP3597328A4 (en
EP3597328A1 (en
Inventor
Akitoshi Matsui
Hirokazu Kondo
Naoki Kikuchi
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JFE Steel Corp
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JFE Steel Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • B22D11/11—Treating the molten metal
    • B22D11/114—Treating the molten metal by using agitating or vibrating means
    • B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • B22D11/103—Distributing the molten metal, e.g. using runners, floats, distributors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/122—Accessories for subsequent treating or working cast stock in situ using magnetic fields
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/16—Controlling or regulating processes or operations
    • B22D11/18—Controlling or regulating processes or operations for pouring
    • B22D11/181—Controlling or regulating processes or operations for pouring responsive to molten metal level or slag level
    • B22D11/186—Controlling or regulating processes or operations for pouring responsive to molten metal level or slag level by using electric, magnetic, sonic or ultrasonic means

Definitions

  • the present invention relates to a continuous steel casting method that includes continuously casting molten steel while applying an AC magnetic field to molten steel present in a mold and controlling, via the AC magnetic field, the flow of the molten steel present in the mold.
  • a slab strand as produced by continuous casting be of high quality.
  • One of the properties a slab strand (hereinafter also simply referred to as a "strand") is required to have is the property that the number of oxide-based non-metallic inclusions (hereinafter simply referred to as "inclusions") in the surface portion and the inner portion of the strand is small.
  • inclusions entrapped in the surface portion and the inner portion of a strand include the following: (1) deoxidation products produced in the step of deoxidizing molten steel with aluminum or the like and suspended in the molten steel; (2) bubbles of argon gas injected into the molten steel present in the tundish or the submerged entry nozzle; and (3) molding powder sprayed onto the surface of the in-mold molten steel and subsequently entrained and suspended in the molten steel. All of these inclusions form surface defects or internal defects in final products, and it is therefore important to reduce inclusions that are entrapped in the surface portion and the inner portion of a strand.
  • one technique used to prevent product defects due to inclusions is to control the flow of molten steel by applying a magnetic field to the molten steel in a mold and utilizing an electromagnetic force due to the magnetic field to prevent deoxidation products, molding powder, and argon bubbles in the molten steel from being entrapped in the solidified shell. Numerous proposals have been made with regard to this technology.
  • JP 2003 320440 A discloses the following technology.
  • An AC magnetic field is applied to a discharge flow discharged from a submerged entry nozzle submerged in the in-mold molten steel, thereby imparting a braking force or horizontal rotating force to the discharge flow in a manner such that the molten steel flow velocity at the surface of the in-mold molten steel is within a range of an inclusion-adherence critical flow velocity or more to a molding-powder entrainment critical flow velocity or less.
  • JP 2000 202603 A discloses a method for continuously casting molten steel.
  • the upper ends of AC magnetic field generation devices are positioned 20 to 60 mm below the surface of the in-mold molten steel, and a submerged entry nozzle having an angle of 1 to 30° in a downward direction is used, whereby the discharge flow from the submerged entry nozzle is controlled so that the discharge flow can impinge on the solidified shell at portions within a range from a center of each of the AC magnetic field generation devices to a position 450 mm downward therefrom.
  • JP 2001 047201 A discloses a method for continuously casting molten steel.
  • discharge ports of a submerged entry nozzle are positioned at locations where the magnetic flux density at the discharge ports is less than or equal to 50% of the maximum magnetic flux density of the AC magnetic field generation devices.
  • EP 1 486 274 A1 discloses a method and an apparatus for controlling flow of molten steel in molds.
  • a molten steel flow velocity on a bath surface is higher than a moldpowder entrainment critical flow velocity of 0.32 m/sec
  • the molten steel flow velocity is controlled to a predetermined molten steel flow velocity by applying a shifting magnetic field to impart a braking force to a discharge flow from an immersion nozzle.
  • the molten steel flow velocity is control to the range of 0.20-0.32 m/sec by applying a shifting magnetic field to rotate the intra-mold molten steel in a horizontal direction.
  • the molten steel flow velocity is controlled to the range of 0.20-0.32 m/sec by applying a shifting magnetic field to impart an accelerating force to the discharge flow from the immersion nozzle.
  • JP 2007 105745 A discloses an electromagnetic stirring device which is arranged in the vicinity of a long side meniscus of a mold having a rectangular cross section and with an electromagnetic brake installed below it.
  • JP 2005 152996 A discloses a method for continuously casting steel casts such that a moving magnetic field moving from both short sides of a casting mold toward an immersed nozzle side is applied to the molten steel in the casting mold, and the braking force is applied to the discharging flow of the molten steel being discharged from the immersed nozzle.
  • the lower end of the discharge port of the immersed nozzle is positioned above the lower end of the iron core of a moving magnetic field application apparatus.
  • the discharge angle of the immersed nozzle is appropriately adjusted such that the trajectory of the flow discharged from the immersed nozzle does not deviate from the range of the arranged position of the iron core of the moving magnetic field application apparatus.
  • the flow is controlled by imparting a braking force or horizontal stirring force to the discharge flow discharged from a submerged entry nozzle, in accordance with the value of the molten steel flow velocity, which is a velocity at the surface of the in-mold molten steel, and therefore the method requires an instrument for measuring or monitoring the molten steel flow velocity, which is a velocity at the surface of the in-mold molten steel.
  • the accuracy of the critical flow velocity prediction formula may deteriorate. It is therefore difficult to say that the technology is a technology that is applicable regardless of at which portion of a back surface of a mold an AC magnetic field generation device is placed.
  • JP 2000 202603 A is a technology that focuses on the location of impingement of the discharge flow discharged from the submerged entry nozzle, but the technology is limited to cases in which AC magnetic field generation devices are placed near the surface of the in-mold molten steel and is therefore not applicable to cases in which AC magnetic field generation devices are placed at a relatively low location with respect to the surface of the in-mold molten steel.
  • JP 2001 047201 A is also limited to cases in which AC magnetic field generation devices are placed near the surface of the in-mold molten steel. Furthermore, the discharge ports of the submerged entry nozzle are provided at locations where the magnetic flux density is less than or equal to 50% of the maximum magnetic flux density, but, in this case, the following concern may arise. Since the discharge flow discharged from the submerged entry nozzle flows downward relative to the AC magnetic field generation devices, inclusions and the like may sink into regions below the AC magnetic field generation devices and cause internal defects in the strand.
  • the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a continuous steel casting method that enables production of a high-quality strand, which is achieved as follows.
  • a continuous steel casting method in which a swirling and stirring flow is created in in-mold molten steel by applying an AC magnetic field to the in-mold molten steel from AC magnetic field generation devices that are placed with mold long sides positioned therebetween, an appropriate AC magnetic flux density is provided in accordance with the distance from the surface of the in-mold molten steel to the location of the peak of the AC magnetic field and with the submergence depth of the submerged entry nozzle.
  • a continuous steel casting method in accordance with the present invention is defined by claim 1.
  • One embodiment of the method includes producing a strand, the producing of the strand including pouring molten steel into a mold for continuous casting and withdrawing a solidified shell from the mold, the solidified shell being a solidified portion of the molten steel, the mold having a pair of mold long sides and a pair of mold short sides with a rectangular interior space being defined within the mold,
  • Another embodiment of the method includes producing a strand, the producing of the strand including pouring molten steel into a mold for continuous casting and withdrawing a solidified shell from the mold, the solidified shell being a solidified portion of the molten steel, the mold having a pair of mold long sides and a pair of mold short sides with a rectangular interior space being defined within the mold,
  • Another embodiment of the method includes producing a strand, the producing of the strand including pouring molten steel into a mold for continuous casting and withdrawing a solidified shell from the mold, the solidified shell being a solidified portion of the molten steel, the mold having a pair of mold long sides and a pair of mold short sides with a rectangular interior space being defined within the mold,
  • a high-quality strand can be produced easily because a swirling and stirring flow is imparted to in-mold molten steel by applying an AC magnetic field with an appropriate magnetic flux density in accordance with the distance from the surface of the in-mold molten steel to the location of the peak of the AC magnetic field and with the submergence depth of the submerged entry nozzle, so that deoxidation products, argon gas bubbles, and molding powder are inhibited from being entrapped in the solidified shell.
  • the present inventors conducted a test and an investigation regarding the flow status of molten steel present in the mold by using a low-melting-point alloy apparatus.
  • a mold having a pair of mold long sides and a pair of mold short sides, which define a rectangular interior space was used; a submerged entry nozzle having two discharge ports (hereinafter also referred to as a "2-port submerged entry nozzle") was placed in a middle portion of the interior space; a situation in which a discharge flow of the molten steel is discharged from each of the discharge ports toward a corresponding one of the mold short sides was simulated; and, the flow status of the molten steel present in the mold, particularly in cases where the location of the peak of the AC magnetic field and the submergence depth of the submerged entry nozzle were varied, was tested.
  • the location of the peak of an AC magnetic field is as follows.
  • the maximum value among root mean square values of the orthogonal component of the magnetic flux density of the AC magnetic field is determined for locations positioned along the mold inner wall surfaces surrounding the interior space of a mold, the location where the maximum value is greatest is the location of the peak of the AC magnetic field, the root mean square values being periodically obtained, the orthogonal component being orthogonal to a corresponding one of the inner wall surfaces.
  • the submergence depth of a submerged entry nozzle is defined as the distance from the surface (also referred to as the "meniscus") of the in-mold molten steel to the upper end of a discharge port of the submerged entry nozzle.
  • the placement locations of AC magnetic field generation devices which were placed facing each other on the back surfaces of the mold long sides, were varied, and the placement location of the submerged entry nozzle, that is, the submergence depth, was varied, and, in those cases, the flow status of a low-melting-point alloy in the mold, the flow velocity distribution thereof in the mold, and the like were investigated by utilizing numerical simulation and a low-melting-point alloy apparatus, which is one-fourth the size of an actual machine.
  • the low-melting-point alloy used was a Bi-Pb-Sn-Cd alloy (melting point: 70°C).
  • the submergence depth of a 2-port submerged entry nozzle is 100 mm or greater and less than 200 mm, and the magnetic flux density at the location of the peak of the AC magnetic field is 0.040 T or greater and less than 0.060 T.
  • the magnetic flux density is determined as follows. Magnetic flux densities at locations 15 mm away from a flat surface of a copper plate of the mold in a direction normal to the flat surface and toward the interior space are considered.
  • the copper plate of the mold is one of the copper plates of the mold and is a plate behind which an AC magnetic field generation device is provided.
  • the flat surface is a surface that forms the interior space.
  • the magnetic flux density at the location of the peak of the magnetic flux density in the strand withdrawal direction is determined.
  • the magnetic flux density is determined as the effective value (root mean square value) of the arithmetic mean of values measured at a desired pitch in the mold width direction. It can be assumed that the measurement pitch in the mold width direction suffices if the measurement pitch is one that sufficiently represents the spatial profile of the magnetic flux density.
  • the magnetic flux density is less than 0.040 T, the swirling and stirring force is low, and as a result, it is difficult to produce the effect of clearing argon gas bubbles and deoxidation products from the solidified shell.
  • the magnetic flux density is greater than or equal to 0.060 T, the swirling and stirring force is too high, which contributes to entrainment of molding powder.
  • the submergence depth of the submerged entry nozzle is less than 100 mm, the distance between the surface of the in-mold molten steel and the discharge flow is too small, which likely contributes to molten steel level fluctuation in the mold. If the submergence depth is greater than or equal to 200 mm, the long length of the main body portion of the submerged entry nozzle increases the cost of the refractory material, and also, from the standpoint of heat resistance and resistance to loading, increases the probability of damage to the submerged entry nozzle, and therefore, contrarily, there is a concern that the operating costs may increase.
  • the submergence depth of a 2-port submerged entry nozzle is 100 mm or greater and less than 300 mm, and the magnetic flux density at the location of the peak of the AC magnetic field is 0.060 T or greater and less than 0.080 T.
  • the location of the peak of the AC magnetic field is a location deeper than that of conditions (A) with respect to the surface of the in-mold molten steel, and therefore a magnetic flux density greater than that of conditions (A) is necessary. That is, if the magnetic flux density is less than 0.060 T, the swirling and stirring force is low, and as a result, it is difficult to produce the effect of clearing argon gas bubbles and deoxidation products from the solidified shell. On the other hand, if the magnetic flux density is greater than or equal to 0.080 T, the swirling and stirring force is too high, which contributes to entrainment of molding powder.
  • the submergence depth of the submerged entry nozzle is less than 100 mm, the distance between the surface of the in-mold molten steel and the discharge flow is too small, which likely contributes to molten steel level fluctuation in the mold. If the submergence depth is greater than or equal to 300 mm, the long length of the main body portion of the submerged entry nozzle increases the cost of the refractory material, and also, from the standpoint of heat resistance and resistance to loading, increases the probability of damage to the submerged entry nozzle, and therefore, contrarily, there is a concern that the operating costs may increase.
  • the submergence depth of a 2-port submerged entry nozzle is 100 mm or greater and less than 300 mm, and the magnetic flux density at the location of the peak of the AC magnetic field is 0.080 T or greater and less than 0.100 T.
  • the location of the peak of the AC magnetic field is a location even deeper than those of conditions (A) and conditions (B) with respect to the surface of the in-mold molten steel, and therefore an even greater magnetic flux density is necessary. That is, if the magnetic flux density is less than 0.080 T, the swirling and stirring force is low, and as a result, it is difficult to produce the effect of clearing argon gas bubbles and deoxidation products from the solidified shell. On the other hand, if the magnetic flux density is greater than or equal to 0.100 T, the swirling and stirring force is too high, which contributes to entrainment of molding powder.
  • the submergence depth of the submerged entry nozzle is less than 100 mm, the distance between the surface of the in-mold molten steel and the discharge flow is too small, which likely contributes to molten steel level fluctuation in the mold. If the submergence depth is greater than or equal to 300 mm, the long length of the main body portion of the submerged entry nozzle increases the cost of the refractory material, and also, from the standpoint of heat resistance and resistance to loading, increases the probability of damage to the submerged entry nozzle, and therefore, contrarily, there is a concern that the operating costs may increase.
  • the discharge angle of the submerged entry nozzle to be used is within the range of 5° in a downward direction to 50° in a downward direction. If the discharge angle is less than 5° in a downward direction, the AC magnetic field cannot sufficiently act on the discharge flow. On the other hand, if the discharge angle is greater than 50° in a downward direction, the downward flow of the discharge flow is too strong, and as a result, there is a concern that deoxidation products and gas bubbles may sink into deep locations with respect to the casting direction and form internal defects, which may act as crack initiation sites when the steel sheet is subjected to forming.
  • the location of the peak of the AC magnetic field is 200 mm or greater and less than 500 mm from the surface of the in-mold molten steel. If the location of the peak of the AC magnetic field is less than 200 mm from the surface of the in-mold molten steel, the submergence depth of the submerged entry nozzle needs to correspond to a location shallower than the location of the peak of the AC magnetic field in order for the AC magnetic field to act on the discharge flow discharged from the submerged entry nozzle, and therefore operational limitations arise and efficient application of the AC magnetic field cannot be accomplished.
  • the location of the peak of the AC magnetic field is a location greater than or equal to 500 mm away from the surface of the in-mold molten steel, the swirling and stirring flow is imparted in a region where the solidified shell is increased in size, and therefore the effect of clearing deoxidation products and argon gas bubbles from the solidified shell is not sufficiently obtained.
  • the frequency of the AC magnetic field is 0.5 to 3.0 Hz and preferably 1.0 to 2.0 Hz. If the frequency is less than 0.5 Hz, the imparting of an electromagnetic force via the AC magnetic field is too intermittent, and therefore the effect of clearing deoxidation products and argon gas bubbles from the solidified shell is unstable. On the other hand, if the frequency is greater than 3.0 Hz, the reduction in magnetic flux density due to the mold and the solidified shell increases, and it is therefore impossible to efficiently apply an AC magnetic field to the in-mold molten steel.
  • Fig. 1 is a diagram illustrating an example of an embodiment of the present invention, schematically illustrating a mold portion of a continuous slab casting machine.
  • Fig. 2 is an enlarged view of a submerged entry nozzle illustrated in Fig. 1 .
  • reference character 1 denotes molten steel; 2, a solidified shell; 3, a surface of in-mold molten steel; 4, a discharge flow; 5, a strand; 6, a mold; 7, a water-cooled mold long side; 8, a water-cooled mold short side; 9, a submerged entry nozzle; 10, a discharge port; 11, an AC magnetic field generation device; 12, molding powder; and ⁇ , a discharge angle of the submerged entry nozzle.
  • the mold 6 includes a pair of mold long sides 7, which face each other, and a pair of mold short sides 8, which face each other and are held between the mold long sides 7.
  • the pair of mold long sides 7 and the pair of mold short sides 8 define a rectangular interior space.
  • a pair of AC magnetic field generation devices 11 are placed on the back surfaces of the respective mold long sides 7.
  • the AC magnetic field generation devices 11 face each other with the mold long sides 7 positioned therebetween.
  • the spacing between the mold long sides that face each other is 200 to 300 mm
  • the submerged entry nozzle 9 has two discharge ports 10, and the discharge angle ( ⁇ ) of each of the discharge ports 10 is within the range of 5° in a downward direction to 50° in a downward direction.
  • the submerged entry nozzle 9 is placed in a middle portion of the rectangular interior space of the mold 6.
  • the discharge flows 4 of the molten steel 1 are discharged from the two discharge ports 10 so that each of the discharge flows 4 flows toward one of the mold short sides 8 that a corresponding one of the discharge ports 10 faces.
  • the molten steel 1 is poured into the interior space of the mold 6.
  • the molten steel 1 is cooled by the mold long sides 7 and the mold short sides 8 to form the solidified shell 2.
  • pinch rolls (not illustrated) are driven in a state in which the discharge ports 10 are immersed in the molten steel 1 in the mold, to start withdrawing the strand 5, which includes an unsolidified portion of the molten steel 1 in the interior, with the solidified shell 2 being the outer shell.
  • the strand withdrawal speed is increased to a predetermined strand withdrawal speed while controlling the location of the surface 3 of the in-mold molten steel to be a substantially fixed location.
  • the submergence depth of the submerged entry nozzle 9 is denoted by L 1
  • L 2 the distance from the surface 3 of the in-mold molten steel to the location of the peak of the AC magnetic field
  • the molding powder 12 is added onto the surface 3 of the in-mold molten steel.
  • the molding powder 12 melts and prevents the molten steel 1 from being oxidized and also flows into a space between the solidified shell 2 and the mold 6 to provide a lubricant effect.
  • argon gas, nitrogen gas or a mixed gas of argon gas and nitrogen gas is injected into the molten steel 1 flowing down through the submerged entry nozzle 9, to prevent deoxidation products suspended in the molten steel from adhering to the inner walls of the submerged entry nozzle.
  • an AC magnetic field is applied from the AC magnetic field generation devices 11 to the molten steel 1 present in the mold, thereby creating a horizontal swirling and stirring flow in the molten steel 1 present in the mold.
  • the frequency of the AC magnetic field is 0.5 Hz or greater and 3.0 Hz or less.
  • the submergence depth (L 1 ) of the submerged entry nozzle 9 is 100 mm or greater and less than 200 mm, and the magnetic flux density at the location of the peak of the AC magnetic field is 0.040 T or greater and less than 0.060 T.
  • the submergence depth (L 1 ) of the submerged entry nozzle 9 is 100 mm or greater and less than 300 mm, and the magnetic flux density at the location of the peak of the AC magnetic field is 0.060 T or greater and less than 0.080 T.
  • the submergence depth (L 1 ) of the submerged entry nozzle 9 is 100 mm or greater and less than 300 mm, and the magnetic flux density at the location of the peak of the AC magnetic field is 0.080 T or greater and less than 0.100 T.
  • the adjustment of the magnetic flux density at the location of the peak of the AC magnetic field is carried out in the following manner. Specifically, the relationship between the electrical power supplied to the AC magnetic field generation devices 11 and the magnetic flux density at a location in the interior space of the mold 6, which is a location 15 mm away from the surface of a copper plate of the mold, at the location of the peak of the AC magnetic field is measured in advance, and the electrical power to be supplied to the AC magnetic field generation devices 11 is adjusted in a manner such that the magnetic flux density at the location of the peak of the AC magnetic field becomes a desired magnetic flux density.
  • a high-quality slab strand can be produced easily because a swirling and stirring flow is imparted to in-mold molten steel by applying an AC magnetic field with an appropriate magnetic flux density in accordance with the distance (L 2 ) from the surface 3 of the in-mold molten steel to the location of the peak of the AC magnetic field and with the submergence depth (L 1 ) of the submerged entry nozzle, so that deoxidation products, argon gas bubbles, and molding powder 12 are inhibited from being entrapped in the solidified shell 2.
  • a test in which approximately 300 tons of molten aluminum killed steel was continuously cast was conducted by using a continuous slab casting machine having a mold such as that illustrated in Fig. 1 .
  • the submergence depth (L 1 ) of the submerged entry nozzle and the distance (L 2 ) from the surface of the in-mold molten steel to the location of the peak of the AC magnetic field were varied.
  • the thickness of the slab strand was 250 mm, and the width thereof was 1000 to 2200 mm.
  • the molten steel pouring flow rate in a steady casting period was 2.0 to 6.5 tons/min (strand withdrawal speed of 1.0 to 3.0 m/min).
  • the frequency of the AC magnetic field was 1.0 Hz.
  • the submerged entry nozzle used was a 2-port submerged entry nozzle having a discharge angle ( ⁇ ) of 25° in a downward direction.
  • Argon gas was injected via an upper nozzle into the molten steel flowing downward through the submerged entry nozzle.
  • the cast slab strand was subjected to hot rolling, cold rolling, and galvannealing successively. Surface defects in the galvannealed steel sheet were measured continuously using an on-line surface defect meter. Overview examination, SEM analysis, and ICP analysis of the measured defects were performed.
  • steelmaking-caused defects deoxidation-product-caused defects, argon-gas-bubble-caused defects, and molding-powder-caused defects
  • evaluations were made based on the number of steelmaking-caused defects per 100 mm in length of the galvannealed steel sheet (product defect index).
  • Invention Examples 1 to 12 correspond to conditions (A) of Table 1
  • Invention Examples 13 to 24 correspond to conditions (B) of Table 1
  • Invention Examples 25 to 36 correspond to conditions (C) of Table 1. All of Invention Examples 1 to 36 had a product defect index within a range of 0.21 to 0.34 (number/100 m) and therefore had a good result.
  • Comparative Examples 25 to 32 are cases in each of which the distance (L 2 ) from the surface of the in-mold molten steel to the location of the peak of the AC magnetic field corresponds to that of conditions (A) of Table 1. However, it was confirmed that, under conditions (B) or conditions (C), too, the product defect index deteriorated in the case where the submergence depth (L 1 ) of the submerged entry nozzle was outside the range of the present invention.
  • the thickness of a strand was within a range of 200 to 300 mm, effects comparable to those described in this example were produced.
  • the shape of the submerged entry nozzle is also not limited to the conditions described in this example, and it was confirmed that when the discharge angle ( ⁇ ) was within the range of 5° in a downward direction to 50° in a downward direction, comparable effects were produced.

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  • Mechanical Engineering (AREA)
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EP17906929.9A 2017-04-25 2017-04-25 Continuous casting method for steel Active EP3597328B1 (en)

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BR (1) BR112019022263B1 (zh)
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JP4407260B2 (ja) * 2003-11-28 2010-02-03 Ｊｆｅスチール株式会社 鋼の連続鋳造方法
JP4746398B2 (ja) * 2005-10-11 2011-08-10 新日本製鐵株式会社 鋼の連続鋳造方法
JP4508209B2 (ja) * 2007-05-10 2010-07-21 住友金属工業株式会社 複層鋳片の連続鋳造方法及び鋳片
JP5104247B2 (ja) * 2007-08-20 2012-12-19 Ｊｆｅスチール株式会社 連続鋳造鋳片の製造方法
JP4505530B2 (ja) * 2008-11-04 2010-07-21 新日本製鐵株式会社 鋼の連続鋳造用装置
JP4807462B2 (ja) * 2009-11-10 2011-11-02 Ｊｆｅスチール株式会社 鋼の連続鋳造方法
CN104942246B (zh) * 2014-03-28 2017-02-22 宝山钢铁股份有限公司 板坯结晶器电磁搅拌的多维电磁调制装置
TWI590892B (zh) * 2015-03-31 2017-07-11 新日鐵住金股份有限公司 鋼的連續鑄造方法

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WO2018198181A1 (ja) 2018-11-01
TW201838744A (zh) 2018-11-01
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CN110573271B (zh) 2021-11-02
EP3597328A4 (en) 2020-04-22
EP3597328A1 (en) 2020-01-22
TWI690377B (zh) 2020-04-11
JP6278168B1 (ja) 2018-02-14
BR112019022263A2 (pt) 2020-05-19
KR20190127894A (ko) 2019-11-13
KR102324300B1 (ko) 2021-11-09
JPWO2018198181A1 (ja) 2019-06-27

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