WO2014030701A1 - Method for continuous casting of steel, and method for manufacturing bar steel - Google Patents
Method for continuous casting of steel, and method for manufacturing bar steel Download PDFInfo
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- WO2014030701A1 WO2014030701A1 PCT/JP2013/072420 JP2013072420W WO2014030701A1 WO 2014030701 A1 WO2014030701 A1 WO 2014030701A1 JP 2013072420 W JP2013072420 W JP 2013072420W WO 2014030701 A1 WO2014030701 A1 WO 2014030701A1
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- slab
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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
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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
- B22D11/12—Accessories for subsequent treating or working cast stock in situ
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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
- B22D11/12—Accessories for subsequent treating or working cast stock in situ
- B22D11/128—Accessories for subsequent treating or working cast stock in situ for removing
-
- 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
- B22D11/20—Controlling or regulating processes or operations for removing cast stock
Definitions
- the present invention relates to a continuous casting method for obtaining a cast slab having excellent center quality, center segregation, center porosity, and few internal cracks, and a method of manufacturing a bar steel that can omit the ingot rolling step.
- This application claims priority based on Japanese Patent Application No. 2012-183179 for which it applied to Japan on August 22, 2012, and uses the content here.
- high-grade strip steel is manufactured by casting a slab with a bloom continuous casting machine having a rectangular mold with a large cross section, rolling the slab in pieces, and then rolling the slab.
- This high-grade steel bar includes steel bars and wire rods.
- the material properties are deteriorated by central segregation and central porosity formed at the end of solidification of the continuous cast slab. Therefore, it is important to cast the slab so as not to generate defects such as center segregation and center porosity.
- Typical methods for reducing the center segregation and the center porosity include a non-solid light reduction method and a complete post-solid reduction method for a slab in a continuous casting machine.
- Patent Document 1 for a round slab having a diameter of 340 mm or less, 0.1 to 3 is obtained by one pass with one set of rolls in a state where the solid phase ratio of the shaft core is 0.3 to 0.7.
- a technique for applying a reduction of 0.0% has been proposed. However, this technique is applied to a small slab having a cross-sectional size of 340 mm or less in diameter.
- the amount of solidification shrinkage also increases. Therefore, in order to obtain the above effect under unsolidified pressure by one pass with one set of rolls, it is necessary to increase the amount of reduction on the slab. There is.
- Patent Document 2 for example, for a round slab having a diameter of 180 mm, the production conditions are controlled so that the equiaxed crystal ratio in the slab is 35% or more, and the central solid fraction of the slab is 0.25.
- a technique for applying a reduction of 2.0 to 3.5% by a pair of flat rolls at a position in the range of ⁇ 0.35 or 0.60 to 0.90 has been proposed.
- this technique when the cross-sectional size of the slab is large, it is necessary to restrict the casting conditions such that the casting speed is reduced more than necessary in order to make the equiaxed crystal ratio in the cross-section of the slab 35% or more. Therefore, it becomes difficult to ensure sufficient production capacity.
- the equiaxed crystal ratio inside the slab is also affected by the steel composition, there are limits to the types of steel to which this technique can be applied.
- the present invention has been made in view of the above situation.
- the present invention is applicable to a wide range of steel types used as strip steel, and is a continuous casting method of a slab capable of achieving both center segregation and reduction of center porosity and prevention of internal cracking of the slab, and steel slab. It is an object of the present invention to provide a method for manufacturing a bar steel that can improve productivity by omitting a block rolling process before rolling.
- a continuous casting method includes a drawing step of drawing a slab in a solid-liquid coexistence state from a cylindrical mold; and after the drawing step; A first reduction step of applying a reduction in a first reduction direction perpendicular to the longitudinal direction of the slab; and a reduction direction orthogonal to both the longitudinal direction and the first reduction direction of the slab.
- the first reduction direction and the first reduction step are performed after the first reduction step with respect to the slab in a completely solidified state and in a state where the temperature of the central portion is higher than the temperature of the surface portion.
- the inner diameter of the mold is 400 mm or more and 600 mm or less; the drawing speed of the slab is 0.35 m / min or more and 0.65 m / min or less;
- the solid phase ratio of the central portion of the slab after the drawing step and before the first reduction step is 0.3 or more and 0.8 or less; in the first reduction direction in the first reduction step
- the rolling reduction per rolling is 0.3% or more and 7.0% or less; the solid phase ratio of the central portion of the slab after the first rolling process and before the second rolling process Is more than 0.8, and the temperature of the central portion of the slab is 150 ° C.
- the reduction in the first reduction direction The rolling reduction per time is 1.5% or more and 7.0% or less
- the reduction ratio per one time of the reduction in the second reduction direction is 1.5% or more and 7.0% or less
- the cross section perpendicular to the longitudinal direction of the slab after the second reduction step The long side may be 235 mm or more and 270 mm or less, and the radius of curvature of the corner may be 5 mm or more and 50 mm or less.
- a method for manufacturing a strip according to an aspect of the present invention includes a continuous casting step of obtaining the slab by the continuous casting method according to (A) or (B); and after the continuous casting step, the slab A rolling step of rolling
- the slab can be applied to a wide range of steel types used as strip steel, and can achieve both center segregation and reduction of center porosity and prevention of internal cracks in the slab. It is possible to provide a method for manufacturing a bar steel capable of improving productivity by omitting the continuous casting method and the block rolling process before rolling the steel slab.
- the thickness direction of the cast slab refers to the roll-down direction (horizontal roll) arranged so that the roll axis direction is parallel to the installation surface of the continuous casting machine and perpendicular to the transport direction of the cast slab. 1 down direction).
- the width direction of the cast slab means a reduction direction (second reduction direction) by a vertical roll disposed so that the roll axis direction is perpendicular to the installation surface of the continuous casting machine. That is, when viewed in a cross section perpendicular to the longitudinal direction of the slab, the longitudinal direction of the slab, the thickness direction of the slab (first reduction direction), and the width direction of the slab (second reduction direction) Orthogonal.
- the center part of the slab is defined as an area that satisfies the following conditions.
- the center of gravity of the central portion matches the center of gravity of the cross section
- the shape of the contour of the central portion matches the shape of the reduced contour of the cross section
- the surface portion of the slab is defined as a region that is 5% from the surface with respect to the slab diameter in the depth direction from the peripheral surface of the slab.
- the cross section of the slab means a cross section perpendicular to the longitudinal direction of the slab.
- the solid phase ratio at the center of the slab is 0.3 to 0.8 (30% by volume to 30% by volume). 80% by volume) is defined as an “unsolidified (solid-liquid coexistence)” state, and when the solid phase ratio exceeds 0.8 (80% by volume) at the center of the slab, “completely solidified” Defined as state. Further, in a continuous casting machine, a region where the solid fraction at the center of the slab is 0.3 to 0.8 is defined as “unsolidified reduction zone”, and the solid fraction at the center of the slab is 0. A region exceeding 8 is defined as a “complete coagulation reduction zone”.
- a slab having a large cross-sectional size has a larger amount of solidification shrinkage than a slab having a small cross-sectional size. Therefore, in order to reduce the center segregation of a slab having a large cross-sectional size, when performing unsolidified reduction, it is necessary to increase the amount of reduction to the slab. For this reason, it becomes easy to generate
- the center portion is at a higher temperature than the surface portion of the slab. Therefore, the deformation resistance of the center part of the slab is smaller than the deformation resistance of the surface part of the slab, and it is possible to increase the degree of reduction penetration into the center part even with a small amount of reduction.
- the slab can be gradually reduced by the reduction permeation degree. In this case, the slab can be reduced while satisfying both the reduction of center segregation and center porosity and the prevention of internal cracks.
- FIG. 1 schematically shows a continuous casting machine 10 for performing the continuous casting method according to the present embodiment. Moreover, in FIG. 2, the rolling form of the slab in the continuous casting method which concerns on this embodiment is shown roughly.
- the continuous casting method according to the present embodiment is as follows: molten steel is supplied from the tundish 1 to the mold 2, and the shape of the cross section is cylindrical (when viewed in a cross section perpendicular to the drawing direction).
- First reduction roll First reduction step of applying a reduction in a first reduction direction perpendicular to the longitudinal direction of the slab 3 using the first reduction roll; when viewed in a cross section perpendicular to the longitudinal direction of the slab 3 Perpendicular to both the longitudinal direction of the slab 3 and the first reduction direction
- the slab 3 (3b, 3c) is in a completely solidified state and in a state where the temperature of the central portion is higher than the temperature of the surface portion after the first reduction step when the reduction direction is the second reduction direction.
- the horizontal roll (first reduction roll) 6a is alternately subjected to the reduction in the first reduction direction and the vertical roll (second reduction roll) 6b in the second reduction direction.
- the drawing process is a process in which the contact surface of the molten steel supplied from the tundish 1 to the mold 2 with the mold 2 is solidified, and the slab 3 coexisting with the solid and liquid is continuously drawn from the bottom of the mold 2.
- the slab 3 drawn out from the mold 2 is supported by the continuous casting machine roll 4 and conveyed to the next process while maintaining its shape.
- the inner diameter of the mold 2 is preferably 400 mm or more, and more preferably 400 mm or more and 600 mm or less when viewed in a cross section perpendicular to the drawing direction. It is most preferable that it is 400 mm or more and 460 mm or less. If the cross-sectional size of the mold 2 is too small, the distance from the meniscus to the position at which the slab 3 is in a completely solidified state is shortened. Therefore, a special casting is required to impart sufficient unsolidified reduction to the slab 3 (3a). There is a risk that the equipment cost will increase because a single reduction device is required.
- the casting speed (drawing speed) of the slab 3 is not particularly limited, but is preferably 0.35 m / min or more and 0.65 m / min or less, and 0.40 m / min or more and 0.60 m / min or less. Is more preferable.
- the casting speed is too slow, the inside of the slab is completely solidified before the slab 3 reaches the unsolidified reduction zone (horizontal roll 5) of the continuous casting machine, and the unsolidified reduction of the slab 3 is impossible. As a result, the effect of suppressing the center segregation may not be obtained.
- the casting speed is too slow, the temperature difference between the center portion of the slab 3 and the surface portion of the slab 3 becomes small in the complete solidification reduction zone (second reduction step), and the center of the slab 3 There is a possibility that the deformation resistance difference between the portion and the surface portion of the slab 3 becomes small. For this reason, there is a possibility that the degree of reduction penetration into the center portion of the slab 3 due to reduction after complete solidification is lowered, and the center porosity is not sufficiently pressed.
- the casting speed (drawing speed) of the slab 3 is too high, the position at which the slab 3 is completely solidified exceeds the length of the continuous casting machine 10, and therefore there is a possibility that the effect of suppressing center segregation cannot be obtained. is there. In addition, it may become impossible to perform the reduction after the complete solidification (second reduction step), and there may be a case where the pressure bonding effect of the center porosity cannot be sufficiently obtained.
- FIG. 3 illustrates the relationship between the drawing speed of the slab 3 and the center segregation, which was investigated using the slab 3 having a circular cross-sectional shape after drawing and a diameter of 450 mm.
- the vertical axis represents the carbon concentration segregation degree
- the horizontal axis represents the casting speed (drawing speed).
- the carbon concentration segregation degree is a value obtained by dividing the carbon concentration measurement value at the center of the slab 3 by the carbon concentration measurement value of the molten steel supplied from the tundish 1 to the mold 2.
- the carbon concentration in the center portion of the slab 3 may be obtained by, for example, collecting chips from the center portion of the slab 3 using a ⁇ 5 mm drill and performing chemical analysis.
- the drawing speed of the slab 3 is 0.35 m / min or more and 0.65 m / min or less, the effect of suppressing the center segregation is preferably obtained.
- first reduction step In the first reduction step, the slab 3 (3a) in an unsolidified state (solid-liquid coexistence state) drawn from the cylindrical mold 2 in the unsolidified reduction zone of the continuous casting machine 10 after the drawing step.
- rolling is performed from the slab thickness direction (first rolling direction) using a horizontal roll (first rolling roll) 5.
- first rolling roll By rolling down the slab 3 (3a) that is in an unsolidified state and having a circular cross-sectional shape, a rolling stress is concentrated on the arc surface of the slab 3 that contacts the horizontal roll 5, so even a small rolling amount can be obtained.
- the reduction permeation into the center of the slab 3 can be increased.
- the deformation resistance of the center portion of the slab 3 in an unsolidified state is smaller than the deformation resistance of the surface portion of the slab 3, the degree of reduction penetration into the center portion is increased even with a small amount of reduction. It is possible. That is, the slab 3 can be squeezed with a good sag permeability by the first reduction process, and the slab 3 can be squeezed while reducing both center segregation and central porosity and preventing internal cracks. it can.
- the reduction ratio of the horizontal rolls 5 to the slab 3 is 0.3 with respect to the thickness of the slab 3 immediately before entering each horizontal roll 5 (the thickness in the first reduction direction). % Or more and 7.0% or less is preferable. That is, it is preferable that the rolling reduction per rolling in the first rolling direction in the first rolling process is 0.3% or more and 7.0% or less. In the present embodiment, it is possible to employ any reduction from light pressure to large pressure in the first reduction process. When applying a large reduction in this embodiment, the diameter of the unsolidified portion (solid-liquid coexisting portion) at the center of the slab 3 in the region where the solid phase ratio at the center of the slab 3 is near 0.7. It is possible to prevent the remaining of internal cracks by applying an equal amount of reduction.
- the reduction ratio of the horizontal rolls 5 to the slab 3 is too small in the first reduction step, the effect of suppressing the center segregation may not be sufficiently obtained. Further, if the rolling reduction ratio of each horizontal roll 5 to the slab 3 is too large, the surface of the slab 3 may be cracked. In order to preferably suppress the occurrence of internal cracks, when the reduction in the first reduction step is limited to light reduction, the reduction rate of each horizontal roll 5 is set to 0.3% or more and 2.2% or less. It is preferable.
- the cumulative reduction ratio of the horizontal rolls 5 to the slab 3 is 3.6% or more and 10% or less.
- the cumulative rolling reduction ratio by each horizontal roll 5 is 3.6% or more and 10% or less, both the center segregation and center porosity of the slab 3 and the prevention of internal cracks in the slab 3 are preferably achieved. be able to.
- the continuous casting machine 10 shown in FIG. 1 six pairs of horizontal rolls 5 are used.
- the slab 3 (3a) in which the central portion was in an unsolidified state (the solid fraction of the central portion was 0.3 or more and 0.8 or less) before being subjected to the first reduction step was measured under the above conditions. After being subjected to the reduction step 1, the central portion is completely solidified (the solid phase ratio of the central portion exceeds 0.8).
- the slab thickness is compared with the slab 3 (3b, 3c) in which the center is in a completely solidified state and the temperature of the center is higher than the temperature of the surface.
- the reduction in the direction (first reduction direction) and the reduction in the slab width direction (second reduction direction) are alternately performed.
- the second reduction step is a completely solidified reduction zone of the continuous casting machine 10 after the first reduction step, in a completely solidified state and in a state where the temperature of the central portion is higher than the temperature of the surface portion.
- slab using a horizontal roll (first reduction roll) 6a using a slab thickness direction (first reduction direction) and a vertical roll (second reduction roll) 6b This is a step of alternately performing reduction from the width direction (second reduction direction).
- the reduction in the slab thickness direction using the horizontal roll 6a and the reduction in the slab width direction using the vertical roll 6b are alternately performed, whereby the inside of the slab 3 (3b, 3c). Center segregation and center porosity can be reduced while preventing cracking.
- a rectangular slab having a reduced corner size (corner) A rounded rectangle with rounded corners).
- the deformation resistance of the center part of the slab 3 is smaller than the deformation resistance of the surface part of the slab 3, so a small amount of reduction Even so, it is possible to increase the degree of reduction in the central portion.
- the temperature of the center part of the slab 3 is 150 degreeC or more higher than the temperature of a surface part, and it is further more preferable that it is 200 degreeC or more higher.
- the upper limit of the temperature of the center part of the slab 3 is not particularly limited, but may be a liquidus temperature determined by the steel composition of the slab 3.
- the temperature of the center part and surface part of the slab 3 for example as follows. Since it is not easy to obtain the temperature of the center portion of the slab 3 by actual measurement, the temperature may be obtained by a cooling simulation (heat transfer calculation model) for performing heat conduction analysis. Specifically, each production such as molten steel temperature, drawing speed, cross-sectional size of the slab 3, heat exchange heat amount between the slab 3 and the continuous casting machine 10, heat release amount of the slab 3, heat generation amount of the slab 3 Based on the conditions, the temperature of the surface portion of the slab 3 and the temperature of the center portion may be obtained by a cooling simulation.
- a cooling simulation heat transfer calculation model
- the relationship between the peripheral surface temperature (surface temperature) of the slab 3, the surface temperature, and the center temperature of the slab 3 in each of the above manufacturing conditions is obtained in advance by cooling simulation, and the slab 3 periphery
- the temperature of the surface portion and the temperature of the center portion of the slab 3 at that time in the manufacturing conditions may be inferred.
- the temperature of the surface part of the slab 3 and the temperature of the center part can be obtained more accurately.
- FIG. 4 shows the temperature difference between the center portion and the surface portion when the slab 3 is completely solidified and then rolled at a cumulative reduction ratio of 20%, and the ultrasonic flaw inspection (UST) after rolling the slab into a slab. : Indicates the relationship with the pass rate by Ultra Sonic Test).
- the vertical axis represents the acceptance rate by ultrasonic flaw detection (UST) on a steel piece
- the horizontal axis represents the temperature difference between the center portion and the surface portion of the slab 3.
- the pass rate by the ultrasonic flaw detection inspection is high, so the effect of the center portion porosity crimping is preferable. You can see that it is obtained.
- the reduction ratio of the horizontal rolls 6a to the slab 3 (3b) is equal to the thickness of the slab 3 (3b) immediately before entering each horizontal roll 6a (the thickness in the first reduction direction).
- it is preferably 1.5% or more and 7.0% or less. That is, it is preferable that the rolling reduction rate per one rolling in the first rolling direction is 1.5% or more and 7.0% or less.
- the reduction ratio of the vertical rolls 6b to the slab 3 (3c) is 1. In comparison with the width (thickness in the second reduction direction) of the slab 3 (3c) immediately before entering the vertical rolls 6b. It is preferably 5% or more and 7.0% or less.
- the rolling reduction per one time in the second rolling-down direction is 1.5% or more and 7.0% or less.
- any reduction from light pressure to large pressure can be employed as in the first reduction step.
- the second reduction process of the present embodiment since the reduction is applied to the slab in a completely solidified state, internal cracks are unlikely to occur even when the reduction is performed by a large reduction.
- the second reduction step if the reduction rate to the slab 3 (3b) by each horizontal roll 6a and the reduction rate to the slab 3 (3c) by each vertical roll 6b are too small, the effect of suppressing the remaining central porosity is obtained. There is a possibility that it cannot be obtained sufficiently.
- the reduction rate of each horizontal roll 6a and each vertical roll 6b is set as follows. It is preferable to be 1.5% or more and 3.3% or less.
- FIG. 5 shows the relationship between the cumulative rolling reduction rate in the second rolling reduction step and the acceptance rate in the ultrasonic flaw detection after rolling the steel slab.
- the vertical axis represents the acceptance rate in ultrasonic flaw inspection (UST) after rolling the steel slab
- the horizontal axis represents the cumulative value of rolling reduction by each roll.
- the center segregation of the slab 3 and the reduction of the center porosity can be preferably obtained.
- the continuous casting machine 10 shown in FIG. 1 seven pairs of horizontal rolls 6a and seven pairs of vertical rolls 6b are used.
- the shape of the slab 3 after the second reduction step is preferably a rounded rectangle having rounded corners when viewed in a cross section perpendicular to the longitudinal direction. Since the shape of the slab 3 after the second reduction step has roundness at the corners, generation of cracks starting from the corners at the time of steel slab rolling is preferably suppressed.
- the slab 3 after the second reduction step is preferably a rounded rectangle having a radius of curvature of 5 mm or more when viewed in a cross section perpendicular to the longitudinal direction.
- the curvature radius of the corner portion is 5 mm or more, the generation of cracks starting from the corner portion during steel slab rolling is further preferably suppressed.
- the upper limit of the radius of curvature of the corner is not particularly limited, but is preferably 50 mm or less.
- the slab 3 after the second reduction process is compared with the above-described cross section (corresponding to the cross-sectional size of the mold 2) of the slab 3 before the first reduction process when viewed in a cross section perpendicular to the longitudinal direction.
- the area% is preferably 58% or less, and more preferably 44% or less.
- the long side of the slab 3 after the second reduction step is 235 mm or more and 270 mm or less.
- secondary cooling with cooling water may be performed on the slab 3 as a cooling step after the drawing step and before the first pressure step.
- the secondary cooling specific water amount is in the range of 0.10 L / kg-steel to 0.55 L / kg-steel.
- the secondary cooling specific water amount becomes too small and it is difficult to maintain the cooling spray shape.
- the secondary cooling specific water amount exceeds 0.55 L / kg-steel, the cooling strength with respect to the slab 3 is locally excessive, and the thermal amplitude during cooling and recuperation increases, and as a result There is a risk of surface cracks occurring in the slab 3.
- the continuous casting method according to the present embodiment is applicable as a continuous casting method for various steel types such as carbon steel or alloy steel.
- the slab 3 obtained by the continuous casting method according to the present embodiment is a slab having a substantially rectangular shape (corner rounded rectangle with rounded corners) having a cross-sectional shape, and has a center segregation and a center porosity.
- the slab 3 is excellent in internal quality with few internal cracks.
- vertical to the longitudinal direction of the slab 3 can be reduced by the continuous casting method which concerns on this embodiment to the size which corresponds after partial rolling. That is, as will be described below, when the strip is manufactured using the slab 3 obtained by the continuous casting method according to the present embodiment, the block rolling process can be omitted.
- the first reduction roll 5 (6a) that performs the reduction in the first reduction direction is disposed horizontally with respect to the installation surface 7 of the continuous casting machine 10, and the second reduction direction.
- the second reduction roll 6 b that applies the reduction to the vertical position was disposed perpendicular to the installation surface 7 of the continuous casting machine 10.
- the first reduction roll 5 (6a) and the second reduction roll 6b The arrangement with respect to the continuous casting machine 10 is not particularly limited. However, like the continuous casting machine 10 shown in FIG.
- the first reduction roll 5 (6a) that performs reduction in the first reduction direction when the conveyance direction (traveling direction) of the slab 3 is partially curved, the first reduction roll 5 (6a) that performs reduction in the first reduction direction. ) Is arranged so that the roll axis direction is parallel to the installation surface 7 of the continuous casting machine 10 and perpendicular to the conveying direction of the cast slab 3, and the second reduction roll 6b that performs the reduction in the second reduction direction is continuous.
- the casting machine 10 is disposed perpendicular to the installation surface 7.
- the continuous casting method according to this embodiment described above will be summarized below.
- the drawing step of drawing the solid-liquid coexisting slab 3 from the cylindrical mold 2 and the slab 3 in the solid-liquid coexisting state after the drawing step are described above.
- a first reduction step of applying a reduction in a first reduction direction perpendicular to the longitudinal direction of the slab 3 and a second reduction in a reduction direction orthogonal to both the longitudinal direction and the first reduction direction of the slab 3 Direction after the first reduction step, the first squeezing direction and the first reduction direction with respect to the slab 3 that is in a completely solidified state and in which the temperature of the central portion is higher than the temperature of the surface portion.
- the inner diameter of the mold 2 is preferably 400 mm or more and 600 mm or less, and the drawing speed of the cast piece 3 is 0.35 m / min or more and 0.65 m / min or less. It is preferable that the solid phase ratio of the central portion of the slab 3 after the drawing step and before the first reduction step is 0.3 or more and 0.8 or less, and the first reduction It is preferable that a reduction rate per one time of the reduction in the first reduction direction in the process is 0.3% or more and 7.0% or less, and after the first reduction process and before the second reduction process.
- the solid phase rate of the central part of the slab 3 is more than 0.8, and that the temperature of the central part of the slab 3 is higher by 150 ° C. than the temperature of the surface part,
- the reduction rate per one time of reduction in the first reduction direction is 1.5% to 7.0%, and the reduction rate per reduction in the second reduction direction is 1.5%.
- it is 7.0% or less
- the shape of the cross section perpendicular to the longitudinal direction of the slab 3 after the second reduction step has a long side of 235 mm or more and 270 mm or less, and the corner portion.
- the curvature radius is preferably 5 mm or more and 50 mm or less.
- the manufacturing method of the strip according to the present embodiment includes a continuous casting process for obtaining a cast piece having a rounded rectangular shape with rounded corners and excellent internal quality by the steel continuous casting method described above, and this continuous casting.
- a rolling step (steel slab rolling step) for rolling the cast slab in order to obtain bar steel, which is a bar steel or a wire rod, without performing ingot rolling after the step.
- the manufacturing method of the strip according to the present embodiment it is possible to omit the batch rolling process that has been conventionally required, and it is possible to improve productivity.
- the quality of the obtained strip is excellent. That is, the above-described continuous casting method of steel appropriately reduces the center segregation and the center porosity, and at the same time, appropriately prevents the internal cracks and performs the first and second reduction steps. Since a slab having a round rectangle is obtained, the internal quality of the strip obtained by subjecting it to the steel slab rolling process is also excellent.
- the manufacturing method of the strip according to the present embodiment is sufficiently applicable to the manufacture of high-grade (high quality) strip.
- Table 1 below shows the cast steel types used in the examples.
- the steel grades were two levels A and B.
- Each steel shown in Table 1 was drawn using a mold having an inner diameter of 450 mm when viewed in a cross section perpendicular to the drawing direction (drawing step).
- the drawn slab was cooled at a secondary cooling specific water amount of 0.15 to 0.20 L / kg-steel as necessary.
- the casting speed (drawing speed) of the slab was 0.30 to 0.60 m / min.
- the unsolidified reduction zone is in the region of 17 to 32 m in the direction of slab conveyance with respect to the meniscus
- the complete solidification reduction zone is in the region of over 32 to 45 m in the direction of conveyance of the slab with reference to the meniscus. there were.
- Table 2 below shows continuous casting conditions for each of the inventive examples and the comparative examples.
- the slab reduction first reduction step
- slab reduction second reduction step
- the pressing and rolling were alternately performed 7 times.
- the casting speed (drawing speed) is changed for each of the inventive examples and the comparative examples.
- test numbers 1 to 4 are examples of the present invention.
- Test Nos. 1 to 4 immediately before entering each horizontal roll for a slab having a solid phase ratio (solid phase ratio in the central portion) of 0.30 or more and 0.80 or less in the unsolidified reduction zone.
- a rolling reduction of 0.6% or 1.6% was given by each horizontal roll.
- the solid fraction in the center is more than 0.80, and the temperature of the center of the slab is 150 ° C. or more (the temperature difference between the inside and outside of the slab) with respect to the surface temperature.
- each horizontal roll gives a reduction of 5.7% on the basis of the slab thickness (thickness in the first reduction direction) immediately before entering each horizontal roll.
- Each vertical roll gave a reduction with a reduction ratio of 5.7% on the basis of the width of the slab immediately before entering (thickness in the second reduction direction). Rolling by the horizontal roll and the vertical roll was alternately performed.
- the final shape of the slab had a long side of 270 mm and a corner radius of curvature of 10 mm.
- Test numbers 5 to 8 are comparative examples.
- the conditions for the secondary cooling specific water amount and the casting speed are the same as those of the example of the present invention.
- the reduction rate of unsolidified reduction is smaller than that of the same steel type of the present invention example, and the reduction after complete solidification is performed only in the slab thickness direction (first reduction direction), and the slab width direction (second reduction) (Direction) is an example that was not performed.
- the conditions for the secondary cooling specific water amount are the same as those of the present invention example.
- the temperature difference between the inside and outside of the slab which is the difference between the center temperature and the surface temperature of the slab, was measured by a slab surface temperature measurement method using a heat transfer calculation model and a contact thermocouple.
- the solid phase ratio at the center of the slab was calculated by a heat transfer calculation model using an alloy phase diagram.
- Each of the obtained slabs was subjected to quality evaluation regarding center segregation at the center, center porosity, and internal cracks.
- steel bars were manufactured by rolling steel slabs, and the presence or absence of Cr carbide generation in these steel bars was evaluated.
- a drawing process was performed using the obtained bar steel, and a quality evaluation on the presence or absence of chevron cracking was performed after the drawing process.
- the center segregation of the slab was evaluated as follows. Chips were collected using a ⁇ 5 mm drill from the center of the cross section perpendicular to the longitudinal direction of the slab after the second reduction step, and the carbon concentration value was measured. Moreover, the carbon concentration value of the molten steel sample extract
- the central porosity of the slab was investigated by performing an ultrasonic flaw inspection using the slab after the second reduction process. And the case where an internal defect was 0.3 mm or less was set as the pass.
- Table 2 the case where the internal defect is 0.3 mm or less is described as 1, the case where the internal defect is more than 0.3 mm and 0.9 mm or less is described as 2, and the case where the internal defect is more than 0.9 mm 3 was written.
- the internal crack of the slab was evaluated as follows. Using the slab after the second reduction step, a cross section (longitudinal section) obtained by cutting along the slab width direction perpendicular to the longitudinal direction of the slab and the casting direction so as to include the core of the slab And the cross-section) were sulfaprinted, and the presence or absence of visual internal cracks was determined.
- the Cr carbide of the bar steel is generated at the remaining portion of the concentrated molten steel inside the slab when the central segregation degree is high.
- the presence or absence of Cr carbide formation in this strip was investigated by observing a cross section parallel to the longitudinal direction of the strip after rolling the steel slab with a microscope. And the thing in which Cr carbide
- the chevron crack after the drawing process was investigated by conducting a tensile test of the sample after the drawing process. And the thing whose tensile fracture surface does not follow a V segregation line was set as the pass.
- Evaluation results are shown in Table 2.
- the slab of the present invention was 1 in terms of center segregation and center porosity, and the internal quality was better than that of the slab of the comparative example.
- the internal quality of each evaluation item was lower than that in the inventive example. That is, it is estimated that the center segregation is insufficiently suppressed and the center porosity is insufficiently crimped. This is because the amount of rolling down to the unsolidified slab is insufficient, the reduction of the rolling penetration into the center of the slab due to the small temperature difference between the inside and outside of the slab, and the amount of rolling down to the fully solidified slab. This is thought to be due to the lack of.
- the slab size can be reduced to a size corresponding to after the bulk rolling at the outlet (downstream side machine end) of the continuous casting machine, and the block rolling process when manufacturing the bar steel is omitted.
- the slab size could not be reduced sufficiently, and when the strip was manufactured, The rolling process could not be omitted.
- continuous casting of a slab that is applicable to a wide range of steel types used as a bar steel and that can achieve both center segregation and reduction of center porosity and prevention of internal cracks in the slab.
- the method and the manufacturing method of the bar steel which can abbreviate
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Abstract
Description
本願は、2012年8月22日に、日本に出願された特願2012-183179号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a continuous casting method for obtaining a cast slab having excellent center quality, center segregation, center porosity, and few internal cracks, and a method of manufacturing a bar steel that can omit the ingot rolling step.
This application claims priority based on Japanese Patent Application No. 2012-183179 for which it applied to Japan on August 22, 2012, and uses the content here.
(A)本発明の一態様に係る連続鋳造方法は、円筒状の鋳型から固液共存状態の鋳片を引き抜く、引き抜き工程と;前記引き抜き工程後に、前記固液共存状態の前記鋳片に対して、前記鋳片の長手方向に垂直な第1圧下方向への圧下を施す、第1の圧下工程と;前記鋳片の前記長手方向及び前記第1圧下方向の双方と直交する圧下方向を第2圧下方向とするとき、前記第1の圧下工程後に、完全凝固状態でありかつ中心部の温度が表面部の温度よりも高い状態にある前記鋳片に対して、前記第1圧下方向及び前記第2圧下方向への圧下を交互に施しながら、前記鋳片の前記長手方向に垂直な断面で見た場合の角部に丸みが有る角丸矩形に成形する、第2の圧下工程と;を備える。 The gist of the present invention is as follows.
(A) A continuous casting method according to an aspect of the present invention includes a drawing step of drawing a slab in a solid-liquid coexistence state from a cylindrical mold; and after the drawing step; A first reduction step of applying a reduction in a first reduction direction perpendicular to the longitudinal direction of the slab; and a reduction direction orthogonal to both the longitudinal direction and the first reduction direction of the slab. When the second reduction direction is set, the first reduction direction and the first reduction step are performed after the first reduction step with respect to the slab in a completely solidified state and in a state where the temperature of the central portion is higher than the temperature of the surface portion. Forming a rounded rectangle with rounded corners when viewed in a cross section perpendicular to the longitudinal direction of the slab while alternately reducing in the second reduction direction; and a second reduction step; Prepare.
(2)鋳片の中心部と表面部とには温度差が存在し、連続鋳造機内では、鋳片の表面部と比較して中心部が高温状態にある。そのため、鋳片の中心部の変形抵抗は、鋳片の表面部の変形抵抗と比較して小さく、小さな圧下量であっても中心部への圧下浸透度を高めることが可能である。特に、鋳型から引き抜かれた鋳片に対し、鋳片厚み方向への未凝固圧下を行い、且つ、鋳片厚み方向及び幅方向からの複数回の完全凝固後圧下を繰り返し行うことで、良好な圧下浸透度で徐々に鋳片を圧下することができる。この場合、中心偏析及び中心ポロシティの低減と、内部割れの防止とを両立しながら鋳片を圧下することができる。
(3)一般的な分塊圧延では、分塊圧延前に鋳片加熱工程で鋳片を十分に加熱するため、分塊圧延時の鋳片の中心部温度と表面部温度との温度差が、連続鋳造機内における鋳片内の温度差と比較して小さい。そのため、鋳片の中心部への圧下浸透度が必然的に小さくなり、中心ポロシティが十分に圧着されない場合がある。一方、連続鋳造機で鋳片を圧下する場合、上述の通り鋳片の中心部と表面部との温度差によって圧下浸透度が良好となる。それゆえ、連続鋳造機によって鋳片を分塊圧延後に相当するサイズまで圧下することで、中心偏析及び中心ポロシティの低減と内部割れの防止とを両立しながら、条鋼を製造するための鋼片圧延に直接適用することが可能なサイズの鋳片を得ることができる。言い換えれば、本実施形態に係る連続鋳造機によって鋳造された鋳片は、分塊圧延を行うことなく、直接、鋼片圧延に供して条鋼を製造することができる。 (1) When the rectangular slab is rolled, a rolling stress is applied to the entire contact surface with the rolling roll, and bulging deformation occurs across the entire non-contact surface with the rolling roll, thereby reducing the rolling penetration into the center of the slab ( The degree of whether or not concentrated reduction at the center of the slab is possible is reduced. Therefore, a large amount of reduction is required to suppress center segregation and to press the center porosity. On the other hand, if the cross-sectional shape is a round slab, the slab concentrates on the arc surface of the slab that is in contact with the reduction roll when the slab is being reduced, so that the reduction stress acts on the center of the slab even with a small reduction amount. It is possible to increase the osmotic pressure.
(2) There is a temperature difference between the center portion and the surface portion of the slab, and in the continuous casting machine, the center portion is at a higher temperature than the surface portion of the slab. Therefore, the deformation resistance of the center part of the slab is smaller than the deformation resistance of the surface part of the slab, and it is possible to increase the degree of reduction penetration into the center part even with a small amount of reduction. In particular, by performing unsolidified reduction in the slab thickness direction on the slab drawn from the mold, and repeatedly performing multiple post-solidification reductions from the slab thickness direction and width direction, The slab can be gradually reduced by the reduction permeation degree. In this case, the slab can be reduced while satisfying both the reduction of center segregation and center porosity and the prevention of internal cracks.
(3) In general segment rolling, the slab is sufficiently heated in the slab heating step before segment rolling, so the temperature difference between the center temperature and the surface temperature of the slab during segment rolling is The temperature difference in the slab in the continuous casting machine is small. For this reason, the reduction permeation into the center of the slab inevitably decreases, and the center porosity may not be sufficiently crimped. On the other hand, when the slab is squeezed by a continuous casting machine, the reduction permeation degree becomes good due to the temperature difference between the center part and the surface part of the slab as described above. Therefore, by rolling the slab to a corresponding size after partial rolling with a continuous casting machine, slab rolling for producing strip steel while achieving both center segregation and reduction of center porosity and prevention of internal cracks. It is possible to obtain a slab of a size that can be applied directly to In other words, the slab cast by the continuous casting machine according to the present embodiment can be directly subjected to steel slab rolling to produce strip steel without performing segment rolling.
図1に、本実施形態に係る連続鋳造方法を行うための連続鋳造機10を概略的に示す。また、図2に、本実施形態に係る連続鋳造方法における鋳片の圧下形態を概略的に示す。図1、2に示すように、本実施形態に係る連続鋳造方法は:タンディッシュ1から鋳型2へと溶鋼を供給し、円筒状(引き抜き方向に垂直な断面で見た場合にその断面形状が円形)である上記鋳型2から、未凝固(固液共存)状態の鋳片3を引き抜く引き抜き工程と;上記引き抜き工程後に、鋳型2から引き抜かれて連続鋳造機ロール(サポートロール)4を経た上記固液共存状態の上記鋳片3(3a)に対して、ロール軸方向が連続鋳造機10の据付面7と平行でかつ上記鋳片3の搬送方向と垂直になるように配置された水平ロール(第1圧下ロール)5を用いて、鋳片3の長手方向に垂直な第1圧下方向への圧下を施す第1の圧下工程と;鋳片3の長手方向に垂直な断面で見た場合に鋳片3の長手方向及び上記第1圧下方向の双方と直交する圧下方向を第2圧下方向とするとき、上記第1の圧下工程後に、完全凝固状態でありかつ中心部の温度が表面部の温度よりも高い状態にある上記鋳片3(3b、3c)に対して、水平ロール(第1圧下ロール)6aによる上記第1圧下方向への圧下と、垂直ロール(第2圧下ロール)6bによる上記第2圧下方向への圧下とを交互に施しながら、鋳片3の長手方向に垂直な断面で見た場合の角部に丸みが有る角丸矩形に鋳片3を成形する第2の圧下工程と;を備える。 <Continuous casting method>
FIG. 1 schematically shows a
引き抜き工程は、タンディッシュ1から鋳型2に供給された溶鋼の鋳型2との接触面を凝固させ、そして固液共存状態の鋳片3を鋳型2の底から連続的に引き抜く工程である。鋳型2から引き抜かれた鋳片3は、連続鋳造機ロール4によって支持されて、形状を保ちながら次工程に搬送される。 (Drawing process)
The drawing process is a process in which the contact surface of the molten steel supplied from the
第1の圧下工程は、引き抜き工程後に、連続鋳造機10の未凝固圧下帯で、円筒状の鋳型2から引き抜かれた未凝固状態(固液共存状態)の鋳片3(3a)に対して、水平ロール(第1圧下ロール)5を用いた鋳片厚み方向(第1圧下方向)からの圧下を施す工程である。未凝固状態でありかつ断面形状が円形である鋳片3(3a)を圧下することで、水平ロール5に接触する鋳片3の円弧面に集中して圧下応力が働くため、小さな圧下量でも鋳片3の中心部への圧下浸透度を高めることできる。加えて、未凝固状態の鋳片3の中心部の変形抵抗は、鋳片3の表面部の変形抵抗と比較して小さいため、小さな圧下量であっても中心部への圧下浸透度を高めることが可能である。すなわち、第1の圧下工程により、良好な圧下浸透度で鋳片3を圧下することができ、中心偏析及び中心ポロシティの低減と内部割れの防止とを両立しながら鋳片3を圧下することができる。 (First reduction step)
In the first reduction step, the slab 3 (3a) in an unsolidified state (solid-liquid coexistence state) drawn from the
第2の圧下工程は、第1の圧下工程の後に、連続鋳造機10の完全凝固圧下帯で、完全凝固状態でありかつ中心部の温度が表面部の温度よりも高い状態にある鋳片3(3b、3c)に対して、水平ロール(第1圧下ロール)6aを用いた鋳片厚み方向(第1圧下方向)からの圧下と、垂直ロール(第2圧下ロール)6bを用いた鋳片幅方向(第2圧下方向)からの圧下とを交互に施す工程である。本実施形態では、水平ロール6aを用いた鋳片厚み方向からの圧下と垂直ロール6bを用いた鋳片幅方向からの圧下とを交互に施すことで、鋳片3(3b、3c)の内部割れを防ぎながら、中心偏析や中心ポロシティを低減することができる。加えて、連続鋳造機10の出口(下流側機端)で、鋳片3の長手方向に垂直な断面で見た場合に、断面サイズが縮小された、角部を有しない矩形鋳片(角部に丸みを有する角丸矩形)を得ることができる。 (Second reduction step)
The second reduction step is a completely solidified reduction zone of the
本実施形態に係る連続鋳造方法は、円筒状の鋳型2から固液共存状態の鋳片3を引き抜く引き抜き工程と、上記引き抜き工程後に、上記固液共存状態の上記鋳片3に対して、上記鋳片3の長手方向に垂直な第1圧下方向への圧下を施す第1の圧下工程と、上記鋳片3の上記長手方向及び上記第1圧下方向の双方と直交する圧下方向を第2圧下方向とするとき、上記第1の圧下工程後に、完全凝固状態でありかつ中心部の温度が表面部の温度よりも高い状態にある上記鋳片3に対して、上記第1圧下方向及び上記第2圧下方向への圧下を交互に施しながら、上記鋳片3の上記長手方向に垂直な断面で見た場合の角部に丸みが有る角丸矩形に成形する第2の圧下工程と、を備える。 The continuous casting method according to this embodiment described above will be summarized below.
In the continuous casting method according to the present embodiment, the drawing step of drawing the solid-
本実施形態に係る条鋼の製造方法は、上記した鋼の連続鋳造方法によって、形状が角部に丸みを有する角丸矩形であり内部品質にも優れる鋳片を得る連続鋳造工程と、この連続鋳造工程後に、分塊圧延を施さずに棒鋼又は線材である条鋼を得るために、上記鋳片を圧延する圧延工程(鋼片圧延工程)と、を備えることを特徴とする。 <Manufacturing method of steel bars>
The manufacturing method of the strip according to the present embodiment includes a continuous casting process for obtaining a cast piece having a rounded rectangular shape with rounded corners and excellent internal quality by the steel continuous casting method described above, and this continuous casting. A rolling step (steel slab rolling step) for rolling the cast slab in order to obtain bar steel, which is a bar steel or a wire rod, without performing ingot rolling after the step.
2:鋳型
3:鋳片
3a:中心部が未凝固状態の鋳片
3b、3c:完全凝固状態の鋳片
4:連続鋳造機ロール(サポートロール)
5:未凝固圧下帯の圧下ロール(水平ロール、第1圧下ロール)
6:完全凝固圧下帯の圧下ロール
6a:水平ロール(第1圧下ロール)
6b:垂直ロール(第2圧下ロール)
7:連続鋳造機の据付面
10:連続鋳造機 1: Tundish 2: Mold 3:
5: Reduction roll of unsolidified reduction zone (horizontal roll, first reduction roll)
6: Rolling roll in a completely solidified rolling
6b: Vertical roll (second reduction roll)
7: Installation surface of continuous casting machine 10: Continuous casting machine
Claims (3)
- 円筒状の鋳型から固液共存状態の鋳片を引き抜く、引き抜き工程と;
前記引き抜き工程後に、前記固液共存状態の前記鋳片に対して、前記鋳片の長手方向に垂直な第1圧下方向への圧下を施す、第1の圧下工程と;
前記鋳片の前記長手方向及び前記第1圧下方向の双方と直交する圧下方向を第2圧下方向とするとき、前記第1の圧下工程後に、完全凝固状態でありかつ中心部の温度が表面部の温度よりも高い状態にある前記鋳片に対して、前記第1圧下方向及び前記第2圧下方向への圧下を交互に施しながら、前記鋳片の前記長手方向に垂直な断面で見た場合の角部に丸みが有る角丸矩形に成形する、第2の圧下工程と;を備えることを特徴とする、連続鋳造方法。 A drawing process of drawing a solid-liquid coexisting slab from a cylindrical mold;
A first reduction step of applying a reduction in a first reduction direction perpendicular to the longitudinal direction of the slab to the slab in the solid-liquid coexistence state after the drawing step;
When the reduction direction perpendicular to both the longitudinal direction and the first reduction direction of the slab is the second reduction direction, after the first reduction step, the slab is in a completely solidified state and the temperature at the center is the surface portion. When the slab in a state higher than the temperature of the slab is viewed in a cross section perpendicular to the longitudinal direction of the slab while alternately performing the reduction in the first reduction direction and the second reduction direction And a second reduction step of forming a rounded rectangle with rounded corners. A continuous casting method, comprising: - 前記鋳型の内径が400mm以上600mm以下であり;
前記鋳片の引き抜き速度が0.35m/分以上0.65m/分以下であり;
前記引き抜き工程後かつ前記第1の圧下工程前における前記鋳片の前記中心部の固相率が、0.3以上0.8以下であり;
前記第1の圧下工程における前記第1圧下方向への圧下の1回当たりの圧下率が、0.3%以上7.0%以下であり;
前記第1の圧下工程後かつ前記第2の圧下工程前における前記鋳片の前記中心部の固相率が0.8超であり、なおかつ前記鋳片の前記中心部の前記温度が前記表面部の前記温度よりも150℃以上高く;
前記第2の圧下工程における、前記第1圧下方向への圧下の1回当たりの圧下率が1.5%以上7.0%以下であり、なおかつ前記第2圧下方向への圧下の1回当たりの圧下率が1.5%以上7.0%以下であり;
前記第2の圧下工程後の前記鋳片の前記長手方向に垂直な前記断面の形状が、長辺が235mm以上270mm以下であり、前記角部の曲率半径が5mm以上50mm以下である;
ことを特徴とする、請求項1に記載の連続鋳造方法。 The inner diameter of the mold is 400 mm or more and 600 mm or less;
The drawing speed of the slab is 0.35 m / min or more and 0.65 m / min or less;
The solid phase ratio of the central portion of the slab after the drawing step and before the first reduction step is 0.3 or more and 0.8 or less;
A reduction rate per one time of reduction in the first reduction direction in the first reduction step is 0.3% or more and 7.0% or less;
The solid phase ratio of the central portion of the slab after the first reduction step and before the second reduction step is more than 0.8, and the temperature of the central portion of the slab is the surface portion. 150 ° C. higher than the above temperature;
In the second reduction step, a reduction rate per one time of reduction in the first reduction direction is 1.5% or more and 7.0% or less, and further, one reduction in the second reduction direction. The rolling reduction is 1.5% or more and 7.0% or less;
The shape of the cross section perpendicular to the longitudinal direction of the slab after the second reduction step has a long side of 235 mm or more and 270 mm or less, and a curvature radius of the corner portion of 5 mm or more and 50 mm or less;
The continuous casting method according to claim 1, wherein: - 請求項1又は2に記載の連続鋳造方法によって前記鋳片を得る連続鋳造工程と;
前記連続鋳造工程後に、前記鋳片を圧延する圧延工程と;を備える
ことを特徴とする、条鋼の製造方法。 A continuous casting step of obtaining the slab by the continuous casting method according to claim 1;
And a rolling step of rolling the slab after the continuous casting step.
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KR20147000538A KR101485743B1 (en) | 2012-08-22 | 2013-08-22 | Continuous casting method for steel and producing method for steel bar and wire rod |
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TWI622434B (en) * | 2017-06-28 | 2018-05-01 | 中國鋼鐵股份有限公司 | Caster and method of producing the same |
TWI647028B (en) * | 2018-06-12 | 2019-01-11 | 中國鋼鐵股份有限公司 | Method for manufacturing cast slab |
CN111360218A (en) * | 2020-04-20 | 2020-07-03 | 中冶京诚工程技术有限公司 | Withdrawal and straightening machine and square and round billet continuous casting machine |
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JPS63215353A (en) * | 1987-03-02 | 1988-09-07 | Daido Steel Co Ltd | Production of continuously cast billet |
JPH11267809A (en) * | 1998-03-20 | 1999-10-05 | Sumitomo Metal Ind Ltd | Method of producing rectangular cast piece by continuous casting |
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JP3405490B2 (en) * | 1995-06-06 | 2003-05-12 | 住友金属工業株式会社 | Method for improving slab quality in continuous casting |
JP2809186B2 (en) * | 1996-02-19 | 1998-10-08 | 株式会社神戸製鋼所 | Continuous casting method |
KR101049844B1 (en) * | 2003-12-17 | 2011-07-15 | 주식회사 포스코 | Reduction of center segregation in width direction of cast steel |
US8245760B2 (en) * | 2007-11-19 | 2012-08-21 | Posco | Continuous cast slab and method for manufacturing the same |
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2013
- 2013-08-22 CN CN201380002126.6A patent/CN103764316B/en active Active
- 2013-08-22 WO PCT/JP2013/072420 patent/WO2014030701A1/en active Application Filing
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JPS63215353A (en) * | 1987-03-02 | 1988-09-07 | Daido Steel Co Ltd | Production of continuously cast billet |
JPH11267809A (en) * | 1998-03-20 | 1999-10-05 | Sumitomo Metal Ind Ltd | Method of producing rectangular cast piece by continuous casting |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
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WO2014203937A1 (en) * | 2013-06-20 | 2014-12-24 | 新日鐵住金株式会社 | Continuous casting method for cast slab |
CN111375737A (en) * | 2020-05-06 | 2020-07-07 | 中冶京诚工程技术有限公司 | Side pressure withdrawal and straightening machine, continuous casting machine and continuous casting method |
Also Published As
Publication number | Publication date |
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JP5545419B1 (en) | 2014-07-09 |
KR101485743B1 (en) | 2015-01-22 |
KR20140072010A (en) | 2014-06-12 |
CN103764316B (en) | 2015-03-11 |
CN103764316A (en) | 2014-04-30 |
JPWO2014030701A1 (en) | 2016-07-28 |
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