WO2015146967A1

WO2015146967A1 - Mold for continuous casting

Info

Publication number: WO2015146967A1
Application number: PCT/JP2015/058874
Authority: WO
Inventors: 修筒江; 秀典井上; 新一平野; 潤二黒木; 剛吉隆
Original assignee: 三島光産株式会社
Priority date: 2014-03-25
Filing date: 2015-03-24
Publication date: 2015-10-01
Also published as: JP5796149B1; JPWO2015146967A1

Abstract

A continuous casting mold (10) comprises long-side copper plates (11, 12) disposed facing one another, short-side copper plates (13, 14) disposed facing one another between the long-side copper plates (11, 12), and long-side support mechanisms (17, 18) and short-side support mechanisms (21, 22) respectively supporting the long-side copper plates (11, 12) and the short-side copper plates (13, 14). The long-side support mechanisms (17, 18) are provided with attachment members (15, 16) which abut and directly support the long-side copper plates (11, 12). The thickness of the long-side copper plates (11, 12) is more than 8 mm and less than 35 mm, and the second moment of area of the attachment members (15, 16) about a horizontal axis is at least 10 times the second moment of area of the long-side copper plates (11, 12) about a horizontal axis.

Description

Continuous casting mold

The present invention relates to a continuous casting mold that suppresses thermal deformation that occurs during casting.

When casting a slab by pouring molten steel into a mold space composed of a copper plate on the long side and the copper plate on the short side disposed opposite to each other, Since solidification shrinkage occurs during the solidification process, a gap is generated between the solidified shell (slab) formed on the mold contact surface side of the molten steel and the inner surface of the mold (copper plate). And when a clearance gap arises, in the part facing the clearance gap of the solidification shell, there exists a problem that a solidification delay will generate | occur | produce because cooling efficiency will fall (growth growth of the thickness of a solidification shell will delay), and it will develop into a cast piece crack. Furthermore, if the solidified shell breaks during casting, there is a risk of accidents in which molten steel leaks from the inside. Therefore, considering the amount of thermal deformation during the casting of each copper plate, a multitaper approximating the solidification shrinkage profile (also referred to simply as the shrinkage profile) of the solidified shell to the inner surface of each copper plate (the surface surrounding the mold space), respectively. There has been proposed a continuous casting mold that is formed and suppressed from generating a gap between the solidified shell and the inner surface of the mold (see, for example, Patent Document 1).

JP 2008-49385 A

However, even if a slab is cast using a continuous casting mold with a multi-taper, for example, casting is performed with a continuous casting mold in which an electromagnetic stirring device is incorporated in a long side support mechanism that supports a copper plate on the long side. When a piece is cast, there still remains a problem that cracks occur at the corners of the slab. Therefore, when the part including the long side support mechanism that supports the copper plate on the long side was analyzed, thermal deformation analysis during casting was performed. In operations where cracks occur in the corner of the slab, continuous casting is performed. It was found that the mold was greatly deformed by heat. This is considered to be caused by a decrease in the bending rigidity of the long side support mechanism because the space for accommodating the electromagnetic stirring device was provided in the long side support mechanism, and the inner surface of the copper plate on the long side It is expected that the shape of the multitaper formed in the above will be greatly collapsed during casting, and a large gap will be formed between the long side copper plate and the short side copper plate between the solidified shell. For this reason, in order to prevent the crack which generate | occur | produces in the corner part of a slab, the contact state of the multi taper which formed the heat deformation which generate | occur | produces in a copper plate during casting on the inner surface of a copper plate, and the solidification shell is maintained. It has been found that it is important to suppress to a certain extent.

The present invention has been made in view of such circumstances, and suppresses thermal deformation generated in the copper plate during casting, and a large gap is formed between the solidified shell formed in the mold and the inner surface of the mold. An object of the present invention is to provide a continuous casting mold that prevents the above.

The continuous casting mold according to the first aspect of the present invention is directed to a copper plate A on the long side that is opposed to the copper plate A, a copper plate B on the short side that is arranged to face the copper plate A, the copper plate A, and the copper plate A In a continuous casting mold having a long side support mechanism and a short side support mechanism that respectively support the copper plate B, the long side support mechanism including an attachment member A that directly contacts and supports the copper plate A,
The thickness of the copper plate A is more than 8 mm and less than 35 mm,
The cross-sectional secondary moment around the horizontal axis of the mounting member A is at least 10 times the cross-sectional secondary moment around the horizontal axis of the copper plate A (and the upper limit is preferably 20 to 60 times).

The continuous casting mold according to the second aspect of the present invention is directed to a copper plate A on the long side that is disposed to face, a copper plate B on the short side that is disposed to face the copper plate A, the copper plate A, and the copper plate A In a continuous casting mold having a long side support mechanism and a short side support mechanism that respectively support the copper plate B, the long side support mechanism including an attachment member A that directly contacts and supports the copper plate A,
The thickness of the copper plate A is more than 8 mm and less than 35 mm,
The sectional secondary moment around the horizontal axis of the long side support mechanism is at least 30 times the sectional secondary moment around the horizontal axis of the copper plate A (and the upper limit is preferably 60 times).

In the continuous casting mold according to the first and second inventions, an electromagnetic stirring device for molten steel can be provided in the long side support mechanism.

In the continuous casting molds according to the first and second inventions, the copper plate A is fixed to the mounting member A via a plurality of fastening means, and the interval between the fastening means adjacent in the vertical and horizontal directions is 120 mm at the longest. Preferably there is.

The continuous casting mold according to the third aspect of the present invention is directed to a copper plate A on the long side that is opposed to the copper plate A, a copper plate B on the short side that is arranged to face the copper plate A, the copper plate A, and the copper plate A In a continuous casting mold having a long-side support mechanism and a short-side support mechanism that respectively support the copper plate B, the short-side support mechanism including an attachment member B that directly contacts and supports the copper plate B.
The thickness of the copper plate B is more than 8 mm and less than 35 mm,
The cross-sectional secondary moment around the horizontal axis of the mounting member B is at least 10 times the cross-sectional secondary moment around the horizontal axis of the copper plate B (and the upper limit is preferably 20 to 60 times).

The continuous casting mold according to the fourth aspect of the invention that meets the above-mentioned object is a copper plate A on the long side that is opposed to the copper plate A, a copper plate B that is on the short side that is placed between the copper plates A, the copper plate A, and the copper plate A In a continuous casting mold having a long-side support mechanism and a short-side support mechanism that respectively support the copper plate B, the short-side support mechanism including an attachment member B that directly contacts and supports the copper plate B.
The thickness of the copper plate B is more than 8 mm and less than 35 mm,
The sectional secondary moment around the horizontal axis of the short side support mechanism is at least 30 times the sectional secondary moment around the horizontal axis of the copper plate B (and the upper limit is preferably 60 times).

In the continuous casting molds according to the first to fourth inventions, it is preferable that the copper plates A and B are each made of a copper alloy material having a thermal conductivity of 240 kcal / m · hr · ° C.

In the continuous casting mold according to the first aspect of the invention, the thickness of the copper plate A is more than 8 mm and less than 35 mm, and the cross-sectional secondary moment of the mounting member A that directly supports the copper plate A is the secondary cross-section of the copper plate A. Since it is at least 10 times the moment, thermal deformation generated in the copper plate A during casting can be suppressed by the mounting member A. In the continuous casting mold according to the second invention, the thickness of the copper plate A is more than 8 mm and less than 35 mm. In addition, since the cross-sectional secondary moment of the long-side support mechanism for supporting the copper plate A is at least 30 times the cross-sectional secondary moment of the copper plate A, the thermal deformation generated in the copper plate A during casting is supported on the long side It can be suppressed by the mechanism. For this reason, for example, even if a taper approximating the contraction profile is formed on the surface of the copper plate A, the collapse of the taper shape can be suppressed, and a large gap is formed between the solidified shell formed in the mold space and the surface of the copper plate A. It is possible to prevent the formation of a gap, to prevent the occurrence of solidification delay in the solidified shell, and to prevent cracks occurring at the corner portion of the slab.

In the continuous casting molds according to the first and second inventions, when an electromagnetic stirring device for molten steel is provided in the long side support mechanism, the molten steel can be solidified while stirring in the mold space. It is possible to produce a high quality slab without any interposition or segregation.

In the continuous casting molds according to the first and second inventions, when the copper plate A is fixed to the mounting member A via a plurality of fastening means, and the interval between the fastening means adjacent in the vertical and horizontal directions is 120 mm at most, The width of the undulation generated by the copper plate A being thermally deformed can be reduced. Thereby, for example, even if a taper that approximates the contraction profile is formed on the surface of the copper plate A, it is possible to further prevent the shape of the taper formed on the surface of the copper plate A from collapsing.

In the continuous casting mold according to the third invention, the thickness of the copper plate B exceeds 8 mm and less than 35 mm, and the cross-sectional secondary moment of the mounting member B that directly supports the copper plate B is expressed by the secondary cross-section of the copper plate B. Since it is at least 10 times the moment, thermal deformation generated in the copper plate B during casting can be suppressed by the mounting member B. In the continuous casting mold according to the fourth invention, the thickness of the copper plate B is more than 8 mm and less than 35 mm. In addition, since the cross-sectional secondary moment of the short-side support mechanism that supports the copper plate B is at least 30 times the cross-sectional secondary moment of the copper plate B, the thermal deformation that occurs in the copper plate B during casting is supported on the short-side side. It can be suppressed by the mechanism. For this reason, for example, even if a taper approximating the contraction profile is formed on the surface of the copper plate B, the collapse of the taper shape can be suppressed, and a large gap is formed between the solidified shell formed in the mold space and the surface of the copper plate B. It is possible to prevent the formation of a gap, to prevent the occurrence of solidification delay in the solidified shell, and to prevent cracks occurring at the corner portion of the slab.

In the continuous casting molds according to the first to fourth inventions, when the copper plates A and B are each formed of a copper alloy material having a thermal conductivity of 240 kcal / m · hr · ° C., Even if the thickness of B is more than 8 mm and less than 35 mm, an excessive decrease in the surface temperature of the copper plates A and B can be suppressed, and the set cooling rate of the solidified shell can be maintained.

It is a top view of the continuous casting mold which concerns on one Example of this invention. (A) is a schematic diagram showing a state of thermal deformation during casting of the copper plate on the long side of the continuous casting mold, and (B) is bent on the copper plate on the long side and the mounting member that directly supports the copper plate on the long side. It is explanatory drawing of the bending moment which gives a deformation | transformation. It is explanatory drawing of the thermal deformation generate | occur | produced along the casting direction in the center of the width direction of a copper plate surface. It is explanatory drawing of the thermal deformation generate | occur | produced along the width direction from the center of the width direction of the copper plate surface.

Subsequently, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIG. 1, a continuous casting mold 10 according to an embodiment of the present invention is disposed so as to be opposed to each other between copper plates (copper plate A) 11, 12 on the long side and

copper plates

11, 12 that are opposed to each other. Short side copper plates (copper plate B) 13, 14; long side support mechanisms (also referred to as water boxes) 17, 18 and short

side support mechanisms

21, 22 for supporting the

copper plates

11, 12 and the

copper plates

13, 14 respectively; The long-

side support mechanisms

17 and 18 have attachment members (attachment members A) 15 and 16 that directly contact and support the

copper plates

11 and 12 and a water cooling unit (not shown) for cooling the attachment members 15 and 16. ) Are attached to the short

side support mechanisms

21 and 22 by direct contact with the copper plates 13 and 14 (attachment member B) 19 and 20 and a water cooling unit (not shown) for cooling the

attachment members

19 and 20. Are provided. Here, a mold space 23 penetrating vertically is formed by the inner side surfaces of the copper plates 11 to 14, and either one or both of the inner side surfaces of the

copper plates

11, 12 and the inner side surfaces of the

copper plates

13, 14 are provided in the mold space 23. A taper is provided that approximates the solidification shrinkage profile of the solidified shell 25 (see FIG. 2) formed from the molten steel 24 injected therein. Details will be described below.

For example, a large temperature gradient (temperature distribution) is generated on the inner side surfaces of the copper plates 11 to 14 on the long side along the longitudinal direction of the copper plates 11 to 14 (the drawing direction of the solidified shell) during casting. For this reason, thermal deformation of the copper plates 11 to 14 during casting occurs depending on the temperature distribution formed in the longitudinal direction of the copper plates 11 to 14. And, in the temperature distribution along the longitudinal direction formed on the inner surface of the copper plates 11 to 14, the temperature of the region in the inner surface of the copper plates 11 to 14 in contact with the portion immediately below the molten steel surface is the highest, The temperature gradually decreases toward both ends (upper end and lower end) of the copper plates 11-14. For this reason, as shown in FIGS. 2A and 2B, thermal deformation of the

copper plates

11 and 12 during casting (as well as the copper plates 13 and 14) causes the

copper plates

11 and 12 to move around the horizontal axis (the copper plates 11 and 12). 13 (around an axis parallel to the width direction) can be approximated as a deformation (bending deformation) when a bending moment M acts.

The

copper plates

11 and 12 abut on the

attachment members

15 and 16 provided on the long

side support mechanisms

17 and 18, and are attached to the attachment members 15 via fastening bolts (not shown) which are an example of a plurality of fastening means. 16 is fixed (supported). For this reason, when the

copper plates

11 and 12 are bent and deformed, the mounting

members

15 and 16 supporting the

copper plates

11 and 12 also follow the deformation of the

copper plates

11 and 12, that is, the mounting

members

15 and 16 are rotated around the horizontal axis ( bending moment M _F of axis) parallel to the width direction of the mounting

members

15 and 16 can be approximated as a deformation (bending deformation) when acted. However, since the bending deformation (resistance to bending deformation) of the mounting

members

15 and 16 and the bending deformation (resistance to bending deformation) of the

copper plates

11 and 12 are different, the mounting

members

15 and 16 are deformed of the

copper plates

11 and 12. As a reaction accompanying the bending deformation following the above, the bending deformability of the

copper plates

11 and 12 is affected by the resistance against the bending deformation of the mounting

members

15 and 16.

The bending stiffness D quantitatively indicating the resistance to bending deformation of the

copper plates

11 and 12 is the elastic modulus and Poisson's ratio of the

copper plates

11 and 12, respectively E, ν, and the width and thickness of the

copper plates

11 and 12 are b and h, respectively. Then, D = Eh ³ / (12 (1-ν ² )). Here, the second moment I about the bending deformation bending moment M in the

copper plate

11, 12 is generated by the action, so is the ^bh 3/12, D is the I · E / (1-ν 2) b . Similarly, the bending stiffness _DF that quantitatively indicates the resistance of the mounting

members

15 and 16 to bending deformation is the elastic modulus and Poisson's ratio of the mounting

members

15 and 16, respectively, E _F and ν _F , and the mounting

members

15 and 16, respectively. If the width and thickness are B and H, respectively, then D _F = E _F H ³ / (12 (1-ν _F ² )). Here, the second moment _{I F} on deformation bending moment _{M F} bending the mounting

member

15, 16 is generated to act, because it is ^BH 3/12, _{D F} is _I F _· E F / (1- ν _F ² ) B.

In order to suppress the bending deformation of the

copper plates

11 and 12 by adjusting the bending stiffnesses D and _DF of the

copper plates

11 and 12 and the

attachment members

15 and 16, for example, the bending stiffness D of the

copper plates

11 and 12 is determined. It is necessary to increase the ratio of the bending rigidity _DF (bending rigidity ratio) of the mounting

members

15 and 16 to the mounting member 15. Therefore, when the bending rigidity ratio D _F / D is obtained, (I _F / I) · (E _F / E) · (b / B) · ((1-ν ² ) / (1-ν _F ² )) Become. Here, since ν and ν _F are values of about 0.3, (1-ν ² ) / (1-ν _F ² ) can be approximated as 1, and D _F / D is (I _F / I) · ( E _F / E) · (b / B). Here, E _F / E is determined by the material forming the mounting

members

15 and 16 and the

copper plates

11 and 12, and b / B is determined by the dimensions of the continuous casting mold. To increase D _F / D, increasing the second moment _{I F} of

members

15 and 16 relative to the moment of inertia of area I of the

copper plate

11 and 12, i.e., cross-sectional

second attachment members

15 and 16 following relative moment of inertia of area I of the

copper plate

11, 12 it is necessary to increase the ratio of the moments I _F (geometrical moment of inertia ratio).

Therefore, assuming the continuous casting mold of a general shape from the continuous casting molds of various shapes currently used, the copper plates 11 to 14 and the mounting

members

15, 16, 19, 20 generated during the continuous casting are respectively used. When the generated thermal deformation (bending deformation) is obtained by numerical calculation (for example, finite element method), the taper approximating the solidification shrinkage profile of the solidified shell 25 formed on the surfaces of the copper plates 11 to 14 does not collapse significantly. Thus, for example, in order that the maximum deviation rate between the tapers before and after thermal deformation is 15% (critical value) or less, it is found that the cross-sectional secondary moment ratio _IF / I must be 10 or more. did. In addition, a critical value is a track record value calculated | required from the past track record in which the slab of favorable quality was obtained.

Further, from the numerical calculation results, when the

copper plates

11 and 12 are fixed to the

attachment members

15 and 16 via a plurality of fastening bolts arranged vertically and horizontally, the

copper plates

11 and 12 are attached on the back surface of the

copper plates

11 and 12 in the vicinity of the fastening bolts. Although the thermal deformation is suppressed under the influence of the bending rigidity _DF of the

members

15 and 16, the region between the fastening bolts is freely thermally deformed on the back surface of the

copper plates

11 and 12, and between the tapers before and after the thermal deformation. It was confirmed that the maximum deviation rate exceeded the critical value. Therefore, when the thermal deformation of the region between the fastening bolts on the back surface of the

copper plates

11 and 12 was determined while changing the spacing between the fastening bolts adjacent in the vertical and horizontal directions, the copper plate was obtained when the spacing between the adjacent fastening bolts was 120 mm or less. It was found that the thermal deformation in the region between the fastening bolts on the back surfaces of 11 and 12 was reduced, and the maximum deviation rate between the tapers before and after the thermal deformation could be made below the critical value. In addition, even if the space | interval between adjacent fastening bolts is less than 60 mm, the thermal deformation of the area | region between the fastening bolts in the back surface of the

copper plates

11 and 12 cannot be reduced greatly, and the

copper plates

11 and 12 and the

attachment members

15 and 16 An increase in processing costs and an increase in the amount of attachment work when the

copper plates

11 and 12 are fixed to the

attachment members

15 and 16 occur. For this reason, the lower limit of the space | interval between adjacent fastening bolts was 60 mm.
Similarly, when fixing the

copper plates

13 and 14 on the short side to the mounting

members

19 and 20 of the short

side support mechanisms

21 and 22 via fastening bolts, between adjacent fastening bolts of a plurality of fastening bolts arranged vertically and horizontally The upper limit of the interval is 120 mm, and the lower limit is 60 mm.

Since the cross-sectional second moment ratio I _F / I can be expressed as BH ³ / bh ³ , if the thickness of the

copper plates

11 and 12 is reduced, I _F / I can be increased. For this reason, in the conventional continuous casting mold, the thickness of the copper plate is 40 to 60 mm, but the thickness of the

copper plates

11 and 12 is more than 8 mm and less than 35 mm. Here, since the

copper plates

11 and 12 on the long side are cooled via the

attachment members

15 and 16 of the long

side support mechanisms

17 and 18, when the thickness of the

copper plates

11 and 12 is 8 mm or less, Although the temperature difference generated in the thickness direction of 12 can be reduced and thermal deformation during casting can be suppressed, the surface temperature of the

copper plates

11 and 12 becomes too low, and the cooling rate of the solidified shell set during casting is reduced. It becomes difficult to satisfy. On the other hand, if the thickness of the

copper plates

11 and 12 is 35 mm or more, the temperature difference generated in the thickness direction of the

copper plates

11 and 12 becomes large, and the thermal deformation of the

copper plates

11 and 12 increases, which is not preferable. For this reason, the thickness of the

copper plates

11 and 12 was set to exceed 8 mm and less than 35 mm (the same applies to the

copper plates

13 and 14 on the short side side).

The copper plates 11 and 12 (the same applies to the copper plates 13 and 14) are made of a copper alloy material (copper alloy) having a thermal conductivity of 240 kcal / m · hr · ° C. or less. By setting the upper limit of the thermal conductivity of the

copper plates

11 and 12 to 240 kcal / m · hr · ° C., the thickness of the

copper plates

11 and 12 is 8 to 35 mm compared to the thickness of the copper plate used in the conventional continuous casting mold. Even if the thickness is reduced, an excessive decrease in the surface temperature of the

copper plates

11 and 12 can be suppressed. The lower limit of the thermal conductivity of the

copper plates

11 and 12 is 140 kcal / m · hr · ° C. Thereby, even if the thickness of the

copper plates

11 and 12 is reduced to 8 to 35 mm, the cooling rate of the solidified shell can be maintained within the range of the cooling rate set in the case of the conventional continuous casting mold, The productivity of the slab can be maintained.

The suppression of the bending deformation of the

copper plates

11 and 12 is achieved by adjusting the bending rigidity D and _DF of the

copper plates

11 and 12 and the

attachment members

15 and 16, respectively.

Space portions

26 and 27 can be formed inside the

side support mechanisms

17 and 18. For this reason, the electromagnetic stirring apparatus (not shown) which electromagnetically stirs the molten steel 24 in the

space parts

26 and 27 can be accommodated. This forms a solidified shell in the mold space 23 while stirring the molten steel 24 in the mold space 23 and prevents a large gap from being generated between the solidified shell and the inner surfaces of the copper plates 11 to 14. Thus, it is possible to produce a high-quality slab that does not cause solidification delay of the solidified shell and does not contain impurities and segregation.

Experimental example

The thermal deformation during casting of the copper plate on the long side of the continuous casting mold was determined by the finite element method. Here, the copper plate has a length of 900 mm along the casting direction, a width of 2450 mm, a thickness of 27 mm, and the mounting member supporting the copper plate has a length of 900 mm along the casting direction and a width of 2500 mm. , The thickness is 85 mm, and the cross-sectional second moment ratio is about 32. Moreover, the space | interval of the fastening bolt which fixes a copper plate to an attachment member is 90 mm. The state of thermal deformation that occurs along the casting direction at the center portion between the fastening bolts arranged near the center of the copper plate surface in the width direction is shown in FIG. In FIG. 4, the state of thermal deformation that occurs from the center in the width direction along the width direction (range from the center in the width direction to 975 mm along the width direction) is shown in FIG. From FIG. 3, the maximum warp width generated by the thermal deformation generated along the casting direction on the copper plate surface is about 0.4 mm, and the warpage amount due to the thermal deformation in the contact region with the solidified shell is about 0.1 mm or less. I understand that. Moreover, it turns out that the maximum curvature width | variety by the thermal deformation generate | occur | produced along a width direction from the width direction center on a copper plate surface will be about 0.28 mm from FIG.

As a comparative example, in a continuous casting mold in which the thickness of the copper plate on the long side is 40 mm, the thickness of the mounting member is 80 mm (therefore, the moment of inertia of the section is about 8), and the fastening bolt interval is 200 mm. Thermal deformation that sometimes occurs in the copper plate on the long side was obtained by the finite element method. The state of thermal deformation that occurs along the casting direction at the center part between the fastening bolts arranged near the center of the copper plate surface in the width direction is shown in FIG. FIG. 4 shows the state of thermal deformation occurring in the width direction from the center in the width direction (range from the center in the width direction to 975 mm along the width direction) in FIG. As shown in FIG. 3, the maximum warp width generated by thermal deformation generated along the casting direction on the copper plate surface was about 0.9 mm. Further, as shown in FIG. 4, the maximum warpage width due to thermal deformation generated from the center in the width direction along the width direction on the copper plate surface was about 0.76 mm. Therefore, in the experimental example, compared to the comparative example, the maximum warp width generated by the thermal deformation generated along the casting direction on the copper plate surface is about 55%, and the center in the width direction is at a height position of 200 mm below the upper end of the copper plate surface. It has been confirmed that the maximum warp width due to thermal deformation generated along the width direction can be reduced by about 59%.

The present invention has been described with reference to the embodiments. However, the present invention is not limited to the configurations described in the above-described embodiments or experimental examples, and the matters described in the claims. Other embodiments and modifications that can be considered within the scope are also included.
Further, the present invention includes a combination of components included in the present embodiment and other embodiments and modifications.
For example, since the copper plate is fixed to the attachment member provided in the long side support mechanism, the resistance against bending deformation of the copper plate was evaluated by the bending rigidity of the attachment member. It is also possible to evaluate the bending rigidity of the long side support mechanism.

Bending stiffness D _S on the long side support mechanism, the elastic modulus and Poisson's ratio of the material constituting the long side supporting mechanism respectively E _S, [nu _S, width and thickness of the respective B _S of the long side support mechanism, Assuming H _S , D _S = E _S H _S ³ / (12 (1-ν _S ² )), and the cross-sectional secondary moment I about the axis passing through the center of the cross section of the long side support mechanism and parallel to the width direction. _S _is because it is _{^{B S H S 3/12,}} D S is the _{_{I S · E S / (1}} -ν S 2) B S. Here, when considering the bending stiffness ratio D _S / D, (I _S / I) · (E _S / E) · (b / B _S ) · ((1-ν ² ) / (1-ν _S ² ) Ν and ν _S can be approximated as 1, so that D _F / D becomes (I _S / I) · (E _S / E) · (b / B _S ), and E _S / E is long. the material forming the side support mechanism and the copper plate, b / B than each determined by the dimensions of the continuous casting mold, in order to increase the D S _{/ D} is the second moment I _S of the long side support mechanism , increasing relative moment of inertia of area I of copper, i.e., is necessary to increase the ratio of the second moment I _S of the long side support mechanism for moment of inertia of area I of a copper plate (the second moment ratio) is there. And assuming a general-shaped continuous casting mold, the thermal deformation occurring in the copper plate and the long side support mechanism generated during continuous casting was determined by numerical calculation, and solidification formed on the surface of the copper plate. It has been found that the cross-sectional second moment ratio I _S / I must be 30 or more so that the taper that approximates the solidification shrinkage profile of the shell does not collapse significantly. Note that the upper limit value of the cross-sectional second moment ratio I _S / I is appropriately determined depending on the shape restriction, the weight restriction, and the cost. Further, the ratio of the sectional secondary moment of the short side support mechanism to the sectional secondary moment of the short side copper plate is also set to 30 or more.

By controlling the thickness of the copper plate and the sectional second moment ratio of the attachment member (or support mechanism) to the copper plate, thermal deformation can be suppressed and stable operation can be performed for a long period of time.

10: Continuous casting mold, 11-14: Copper plate, 15, 16: Mounting member, 17, 18: Long side support mechanism, 19, 20: Mounting member, 21, 22: Short side support mechanism, 23: Mold space 24: Molten steel 25: Solidified shell 26, 27: Space

Claims

The copper plate A on the long side opposed to each other, the copper plate B on the short side arranged between the copper plates A, the long side support mechanism and the short side for supporting the copper plate A and the copper plate B, respectively. In a continuous casting mold having a support mechanism, the long side support mechanism including an attachment member A that directly supports the copper plate A in contact with the copper plate A,
The thickness of the copper plate A is more than 8 mm and less than 35 mm,
A continuous casting mold characterized in that a cross-sectional secondary moment around the horizontal axis of the mounting member A is at least 10 times the cross-sectional secondary moment around the horizontal axis of the copper plate A.
The copper plate A on the long side opposed to each other, the copper plate B on the short side arranged between the copper plates A, the long side support mechanism and the short side for supporting the copper plate A and the copper plate B, respectively. In a continuous casting mold having a support mechanism, the long side support mechanism including an attachment member A that directly supports the copper plate A in contact with the copper plate A,
The thickness of the copper plate A is more than 8 mm and less than 35 mm,
A continuous casting mold characterized in that a cross-sectional secondary moment around the horizontal axis of the long-side support mechanism is at least 30 times the cross-sectional secondary moment around the horizontal axis of the copper plate A.
The continuous casting mold according to claim 1, wherein an electromagnetic stirring device for molten steel is provided in the long side support mechanism.
The continuous casting mold according to any one of claims 1 to 3, wherein the copper plate A is fixed to the mounting member A via a plurality of fastening means, and the interval between the fastening means adjacent in the vertical and horizontal directions is long. A continuous casting mold characterized in that it is 120 mm.
The copper plate A on the long side opposed to each other, the copper plate B on the short side arranged between the copper plates A, the long side support mechanism and the short side for supporting the copper plate A and the copper plate B, respectively. In a continuous casting mold having a support mechanism, the short side support mechanism including a mounting member B that directly contacts and supports the copper plate B,
The thickness of the copper plate B is more than 8 mm and less than 35 mm,
A continuous casting mold characterized in that a cross-sectional secondary moment around the horizontal axis of the mounting member B is at least 10 times the cross-sectional secondary moment around the horizontal axis of the copper plate B.
The copper plate A on the long side opposed to each other, the copper plate B on the short side arranged between the copper plates A, the long side support mechanism and the short side for supporting the copper plate A and the copper plate B, respectively. In a continuous casting mold having a support mechanism, the short side support mechanism including a mounting member B that directly contacts and supports the copper plate B,
The thickness of the copper plate B is more than 8 mm and less than 35 mm,
A continuous casting mold characterized in that a cross-sectional secondary moment around the horizontal axis of the short-side support mechanism is at least 30 times the cross-sectional secondary moment around the horizontal axis of the copper plate B.
The continuous casting mold according to any one of claims 1 to 6, wherein each of the copper plates A and B is formed of a copper alloy material having a thermal conductivity of 240 kcal / m · hr · ° C. A continuous casting mold characterized by that.