JP2006272429A - Mold for continuous casting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for continuous casting with which a cast slab having good quality can be produced and the stable quality can be kept for a long period of time as compared with the conventional mold by restraining and further, preventing the development of corrosion in the lower end part of a cooling plate. <P>SOLUTION: In the mold for continuous casting, which is provided with the cooling plate 12 with many water guiding grooves 11 arranged at the back surface and a supporting member 14 fixed to the back surface side of the cooling plate 11 by a fitting means 13 via O-rings 18 disposed around the water guiding grooves 11, and in which the cooling of the cooling plate 12 is performed by making cooling water flow into each water guiding groove 11 via a water supplying part 15 and a water discharging part 16 arranged at the supporting member 14, the cooling plate 12 is provided with a cooling part 19 at the lower side of the O-ring 18 positioned at the lower end part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a continuous casting mold for casting molten steel.

Conventionally, a continuous casting mold (hereinafter also simply referred to as a mold) used in a continuous casting facility has a pair of narrow cooling members (also referred to as short piece members) sandwiched between the short side members. A long side member (also referred to as a long piece member) that is a pair of wide cooling members that are arranged, bolts are attached to both ends of the opposing long side member, and the short side member is fixed with a nut via a spring It has a structure.
As shown in FIGS. 7A and 7B, the long-side member includes a copper plate 81 (an example of a cooling plate) in which a large number of water guide grooves 80 are provided on the back surface in the vertical direction, and a bolt on the back surface side of the copper plate 81. And a back plate (also referred to as a cooling box) 82 fixed by the. A drainage portion 83 and a water supply portion 84 are respectively provided at the upper end portion and the lower end portion of the back plate 82 on the side in contact with the copper plate 81, and the cooling water flowing in from the water supply portion 84 is passed through the water guide groove 80 to the drainage portion 83. To cool the copper plate 81. Moreover, since the O-ring 85 is disposed between the copper plate 81 and the back plate 82 so as to surround the water guide groove 80, the drainage part 83, and the water supply part 84, water leakage from the long side member can be prevented. The short side member also has substantially the same configuration as the long side member except that its width is different, and the mold body is composed of the copper plates of the long side member and the short side member (for example, patents) Reference 1).
As shown in FIG. 8 (A), a plurality of cooling water sprays 89 are supplied while continuously supplying a molten metal to the mold 86 having such a structure and continuously drawing out a cast piece 87 formed by solidification in the mold 86. Cooling with cooling water ejected from

JP 2003-136204 A

However, when continuous casting is performed using the above-described continuous casting mold 86, as shown in FIG. 8B, corrosion (shaded portion in the figure) is present at the lower end of the surface (casting surface) side of the copper plate 81. It has occurred.
As shown in FIGS. 7A and 7B, the cooling structure for the continuous casting mold 86 that has been conventionally used is that a large number of water guiding grooves 80 are not formed up to the lower end portion of the copper plate 81. Temperature rises easily. For this reason, as shown in FIG. 8 (C), the lower end of the copper plate 81 bulges and deforms more toward the slab 87 than the other portion as the temperature rises at the lower end of the copper plate 81, and the surface of the copper plate 81 A gap (space) 90 is generated between the surface of the slab 87 (solidified shell). Further, since the slab 87 drawn out from the mold 86 is cooled by the cooling water ejected from the cooling water spray 89, the generated steam accumulates in the gap 90. From this, it is understood that the steam accumulated in the gap 90 is likely to stay in the gap 90 portion, causing corrosion of the lower end portion of the copper plate 81.
Thus, when corrosion occurs in the copper plate 81, for example, there is a possibility that slab quality and mold life may be greatly reduced.

The present invention has been made in view of such circumstances, and can suppress and further prevent the occurrence of corrosion at the lower end of the cooling plate to produce a slab of good quality and maintain stable quality for a longer period of time than before. An object of the present invention is to provide a continuous casting mold.

The continuous casting mold according to the present invention that meets the above object is fixed to the back surface side of the cooling plate by a mounting means through an O-ring surrounding the cooling plate with a cooling plate provided with a large number of water guiding grooves on the back surface. A continuous casting mold that cools the cooling plate by flowing cooling water through each water guide groove through a water supply unit and a drainage unit provided in the support member.
The cooling plate is provided with a cooling part below the O-ring located at the lower end.

Moreover, in the continuous casting mold according to the present invention, it is preferable that the cooling part is constituted by a cooling water flow path that is connected to the water supply part and a lower end part of each water guide groove through a communication part. .

In the continuous casting mold according to the present invention, a partition member that divides the communication portion into two stages in the depth direction is disposed in the communication portion, and the cooling water that has flowed in from the water supply portion flows along the partition member. It is preferable that the O-ring located at the lower end is lowered to the lower side and led to the cooling water flow path, and then raised to flow into the water guiding groove.

In the continuous casting mold according to the present invention, it is preferable that the cooling section is a cooling water passage provided across the width direction of the cooling plate.

In the casting mold for continuous casting according to the present invention, the cooling water passage is disposed at a cooling water supply passage communicating with the water supply portion, and a width direction end portion of the cooling plate, and is connected to the drainage portion. It is preferable that they communicate with each other.

In the continuous casting mold according to the present invention, it is preferable that a lower end position of the cooling portion is within a range of 20 mm upward from a lower end position of the cooling plate.

Since the casting mold for continuous casting according to claims 1 to 6 is provided with a cooling portion on the cooling plate on the lower side of the O-ring located at the lower end, the temperature rise at the lower end of the cooling plate can be suppressed, and the deformation amount thereof can be reduced. It can be made smaller than before. As a result, it is possible to suppress and further prevent the lower end of the cooling plate from projecting to the slab side relative to the other parts, thus preventing stagnation of steam in the gap generated between the cooling plate surface and the slab surface. It is possible to suppress corrosion at the lower end of the cooling plate.

In particular, in the continuous casting mold according to the second aspect of the present invention, since the cooling part is constituted by the cooling water flow path communicating with the water supply part and each water guide groove, the cooling plate lower end can be cooled with a simple structure.

In the continuous casting mold according to the third aspect of the invention, since the partition member is disposed in the communication portion that connects each cooling water flow path to the water guide groove and the water supply portion, for example, the cooling water is retained in the cooling water flow path. It is possible to continuously flow through the cooling water flow path without increasing the cooling efficiency of the lower end of the cooling plate.

In the continuous casting mold according to the fourth aspect of the present invention, since the cooling part is constituted by the cooling water passage provided across the width direction of the cooling plate, the cooling plate lower end can be cooled with a simple structure.

In the continuous casting mold according to the fifth aspect of the present invention, since the cooling water passage is communicated with the cooling water supply passage communicating with the water supply portion, the cooling water can be easily supplied to the cooling water passage. Further, since the cooling water passage is arranged at the end portion in the width direction of the cooling plate and communicated with the cooling water discharge passage communicating with the drainage portion, the drainage of the cooling water supplied to the cooling water passage is easy.

Since the continuous casting mold of the invention according to claim 6 defines the lower end position of the cooling portion, the lower end portion of the cooling plate can be accurately cooled.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1A is a rear view of the long side member of the continuous casting mold according to the first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line aa in FIG. 2A is a partially enlarged view of the lower end portion of the long side member, FIG. 2B is a cross-sectional view taken along line bb in FIG. 2A, and FIG. 3A is a surface temperature analysis of the long side member. Explanatory drawing of a result, (B) is explanatory drawing of the displacement amount analysis result of the same long side member, FIG.4 (A) is a rear view of the long side member of the casting mold for continuous casting which concerns on the 2nd Embodiment of this invention. , (B) is a cross-sectional view taken along the line cc in FIG. 4 (A), FIG. 5 (A) is a partially enlarged view of the lower end portion of the long side member, and (B) is a line dd in FIG. FIG. 6A is an explanatory view of the surface temperature analysis result of the long side member, and FIG. 6B is an explanatory view of the displacement amount analysis result of the long side member.

As shown in FIGS. 1A and 1B, the continuous casting mold (hereinafter also simply referred to as a mold) according to the first embodiment of the present invention has a pair of narrow cooling members as described above. Are manufactured by combining a short side member (also referred to as a short piece member) and a long side member (also referred to as a long piece member) 10 which are a pair of wide cooling members. A copper plate (an example of a cooling plate) 12 made of copper or a copper alloy, which is an example of a metal having good thermal conductivity, and provided with a large number of water guide grooves 11 (here, 11) on the back surface, and a copper plate 12 The back plate 14 (also referred to as a cooling box or a water box), which is an example of a support member fixed by the attachment means 13, is provided on the lower side and the upper side of the back plate 14 on the side in contact with the copper plate 12. The water guide groove 11 is cooled through the water supply section 15 and the drain section 16 Water (e.g., industrial water) is intended to cool the copper plate 12 by flowing. The short-side member of the continuous casting mold has substantially the same configuration as the long-side member 10 described above, and the mold body is composed of the copper plate 12 of the long-side member 10 and the copper plate of the short-side member (an example of a cooling plate). Has been. Thus, since the short side member is only different in width from the long side member 10, the description thereof will be omitted, and only the long side member 10 will be described in detail below.

As shown in FIGS. 1 (A), 1 (B), 2 (A), 2 (B), a copper plate 12 (for example, a thickness of about 10 mm or more and 100 mm or less) includes an internal thread portion formed on the copper plate 12 and an internal thread. It is fixed to a back plate 14 made of stainless steel (for example, a thickness of about 50 mm or more and 500 mm or less), for example, by mounting means 13 (21 locations in this case) comprising male screws that are screwed into the portion and fastened to the back plate 14. . A groove is formed in the periphery of the back plate 14 surrounding the water supply portion 15, the drainage portion 16 of the back plate 14, and the water guide groove 11 of the copper plate 12, and an O-ring 18 is disposed here. Thereby, the adhesiveness of the copper plate 12 and the back plate 14 is improved, and the leakage of the cooling water from the water guide groove 11 is prevented.

Further, in order to attach a male screw, a seal washer that can be waterproofed is disposed in advance in a hole (not shown) formed in the back plate 14 to prevent leakage of cooling water from a portion to which the male screw is attached. .
As a result, the cooling water is supplied uniformly from the water supply port (not shown) provided in the lower water supply section 15 of the back plate 14 to each water guide groove 11 and flows from the lower side to the upper side of the copper plate 12. Is discharged from the drain port 17 provided in the drain part 16 on the upper side of the back plate 14 to cool the copper plate 12.

As shown in FIGS. 1B and 2, the depth D <b> 1 of each water guide groove 11 is, for example, about 1/3 or more and 2/3 or less of the thickness of the copper plate 12. Moreover, the water guide groove 11 is linear, and is provided with a predetermined pitch (for example, about 10 mm or more and 40 mm or less).
A cooling unit 19 is provided further below the lower end position of the water guide groove 11, that is, below the O ring 18 located at the lower end part (including the lower part of the O ring 18). The cooling unit 19 includes cooling water passages 21 respectively connected to the water supply unit 15 and the lower end portions of the water guide grooves 11 via the communication unit 20, and the lower end position D <b> 2 is from the lower end position of the copper plate 12. It is in the range of 20 mm or less upward (preferably within the range of 3 mm or more and 15 mm or less, and more preferably in the range of 3 mm or more and 10 mm or less based on the lower end position of the copper plate 12).

Each cooling water channel 21 is provided downward from the lower side of the O-ring 18, and together with the communication groove 22 that connects each cooling water channel 21 and the water guide groove 11, from the lower end of the copper plate 12 to the water guide groove 11. It is formed by perforating the copper plate 12 and attaching a lid (also referred to as a stopper) 23 to the lower end thereof. The shape of the cooling water passage 21 is substantially circular in cross section, and its maximum inner width is equal to or more than about twice that of the water guide groove 11, and its bottom position in the depth direction is substantially equivalent to that of the water guide groove 11 (here, Slightly deeper than the water guide groove 11).
Further, the portion of the copper plate 12 corresponding to the position of the cooling water supply unit 15 is, for example, about 1/2 to 3/4 of the depth of the water guide groove 11 and is shallower than the water guide groove 11 (for example, the communication groove). Engraved up to 22). For this reason, the shape of the lower end portion of the communication groove 22, that is, the position below the coolant supply portion 15 is the same as that of the coolant flow channel 21.
The engraved portion becomes a cooling water inflow portion 24 that allows the water supply portion 15 and the cooling water passage 21 to communicate with each other, and the communication portion 20 is configured by the cooling water inflow portion 24 and the communication groove 22 described above. Yes.

A cooling water adjusting plate (an example of a partition member) 25 is disposed at the bottom position in the depth direction of the cooling water inflow portion 24, and is fixed to a step portion generated by the engraving of the copper plate 12 with a screw 26.
The cooling water adjusting plate 25 is made of, for example, corrosion-resistant stainless steel, copper, or copper alloy, and has a plurality of (here, three) claw portions 27 at the lower end thereof as shown in FIG. The tip portion of the claw portion 27 is disposed inside the lower end portion of the communication groove 22. Further, the cooling water adjusting plate 25 is disposed in a substantially vertical state, and an upper portion thereof is bent toward an upper end portion position of the water supply unit 15, and a lower end position thereof is disposed at an upper end position of the O-ring 18.
In addition, as a cooling water adjustment board, what has one nail | claw part can also be used.

Thus, since the cooling water adjustment plate 25 which divides | segments the communication part 20 into two steps in the depth direction is arrange | positioned at the communication part 20, the cooling water which flowed into the cooling water inflow part 24 from the water supply part 15 is received. Without flowing directly into the water guide groove 11, it is lowered to the lower side of the O-ring 18 along one surface side of the cooling water adjusting plate 25, guided to the cooling water flow path 21, and then reversed so that the cooling water adjusting plate 25 It can be raised along the surface side and allowed to flow to the water guide groove 11.
In order to suppress and further prevent the cooling water from staying in the cooling water flow path, the lower end position of the cooling water adjusting plate is the same position as the O-ring, and further the lower position of the O-ring (the position of the cooling water flow path) It is also possible to extend up to. Moreover, although the lower end position of the part fixed with the screw 26 of the cooling water adjustment plate is a position corresponding to the intermediate position in the height direction of the water supply unit, in order to increase the rigidity of the claw portion of the cooling water adjustment plate, the water supply unit It is also possible to extend to a position corresponding to the lower end position.

Next, the results of numerical analysis of the surface temperature and displacement (expansion) amount of the copper plate 12 using the long side member 10 of the continuous casting mold will be described. In the numerical analysis, a copper plate 81 having the configuration shown in FIG. 7 was used as a conventional product to be compared. The set flow rate of the cooling water is 4 m / second for the cooling water passage 21 and 8.5 m / second for the water guide groove 11.
As shown in FIG. 3A, the surface temperature of the conventional copper plate 81 increases rapidly from the lower end position of the copper plate 81, that is, the distance from the mold TOP is 800 mm to the lower end (about 430 ° C.). )is doing. This is because the copper plate 81 at the lower position of the O-ring 85 is not properly cooled.
On the other hand, the surface temperature of the copper plate 12 of the present embodiment is such that the cooling of the copper plate 12 is appropriately performed by providing the cooling water channel 21 in the copper plate 12, so that there is no temperature rise at the lower end of the copper plate 12, The temperature is smoothly lowered toward the lower end of the copper plate 12.

For this reason, as shown in FIG. 3 (B), in the case of the conventional product, the amount of displacement in the slab direction at the lower end of the copper plate 81 suddenly increases, whereas the lower end of the copper plate 81 is expanded, In this embodiment, such expansion is not confirmed.
From the above, since it is possible to suppress and further prevent the occurrence of a gap (space) between the copper plate surface and the slab surface as in the prior art, the occurrence of corrosion at the lower end of the copper plate can be suppressed. Accordingly, it is possible to provide a continuous casting mold that can produce a cast piece with good quality and can maintain stable quality for a longer period of time than before.

Next, a continuous casting mold according to the second embodiment of the present invention (hereinafter also simply referred to as a mold) will be described. What is the above-described continuous casting mold according to the first embodiment of the present invention? Since the configuration of the cooling water passage (an example of the cooling part) 32 provided in the copper plate (an example of the cooling plate) 31 of the long side member 30 is substantially the same, the same members are denoted by the same numbers. .
As shown in FIGS. 4A, 4B, 5A, and 5B, a plurality of water guide grooves 33 having substantially the same configuration as the water guide grooves 11 are formed on the back surface of the copper plate 31 in the vertical direction. Has been.
A cooling water passage 32 is provided across the width direction of the copper plate 31 further below the lower end position of the water guide groove 11, that is, below the O ring 18 located at the lower end portion (including the lower part of the O ring 18). It has been. The lower end position D3 of the cooling water passage 32 is within a range of 20 mm or less from the lower end position of the copper plate 31 (preferably upward with respect to the lower end position of the copper plate 31 and within a range of 3 mm to 15 mm, more preferably 3 mm or more and 10 mm or less).

The cooling water passage 32 is formed by drilling the copper plate 31 from one end portion (right side in FIGS. 4A and 5A) in the horizontal direction, and then attaching a lid 34 to the one end portion. Is provided. The shape of the cooling water passage 32 is substantially circular in cross section, and the inner diameter thereof is, for example, about 2 to 5 times the inner width of the water guide groove 33. In addition, it is also possible to make the shape of the cooling water passage into a rectangular cross section (square or rectangular).
Since a cooling water supply path 35 communicating with the water supply unit 15 through the water guide groove 33 is provided at the central position in the longitudinal direction of the cooling water path 32, it is possible to facilitate the supply of the cooling water to the cooling water path 32. Yes. The cooling water supply passage 35 is formed by drilling from the lower end portion of the copper plate 31 upward to the water guide groove 33 and attaching a lid 36 to the lower end portion. In addition, when the shape of the cooling water passage is a square cross section, a rectangular slit is formed from the back surface of the copper plate, and a portion other than the portion corresponding to the cooling water passage is covered with a plug to form a cooling water passage. be able to.

In addition, a cooling water discharge passage 37 is provided on one side of the cooling water passage 32, that is, on the right side of the attachment means 13 disposed at the end in the width direction of the copper plate 31. An upper end portion of the cooling water discharge path 37 penetrates toward the back surface side of the copper plate 31 to form a discharge port 38, and the discharge port 38 communicates with the drainage unit 16. The other side of the cooling water passage 32 has the same configuration.
The cooling water discharge passage 37 is formed by drilling upward from the lower end portion of the copper plate 31 and attaching a lid 39 to the lower end portion.

Thus, if the copper plate is wide, the cooling water supply path is near the center in the width direction of the copper plate, and the cooling water discharge path is symmetrical with respect to both ends of the copper plate in the width direction (for example, the center line in the width direction of the copper plate). However, if the copper plate is not wide, a cooling water supply passage and a cooling water discharge passage can be provided at both ends in the width direction of the copper plate.

Next, the results of numerical analysis of the surface temperature and displacement (expansion) amount of the copper plate 31 using the long side member 30 of the continuous casting mold will be described. In the numerical analysis, a copper plate 81 having the configuration shown in FIG. 7 was used as a conventional product to be compared. The set flow rate of the cooling water is 5 m / second for the cooling water passage 32 and 8.5 m / second for the water guide groove 33.
As shown in FIG. 6A, the surface temperature of the conventional copper plate 81 rapidly increases from the lower end position of the copper plate 81, that is, the distance from the mold TOP from the position of 800 mm to the lower end (about 430 ° C.). )is doing. This is because the copper plate 81 at the lower position of the O-ring 85 is not properly cooled.
On the other hand, the surface temperature of the copper plate 31 of the present embodiment is that the cooling of the copper plate 31 is appropriately performed by providing the cooling water passage 32 in the copper plate 31, and therefore the temperature at the lower end of the copper plate 31 compared to the conventional product. The rise is greatly suppressed.

For this reason, as shown in FIG. 6B, in the case of the conventional product, the amount of displacement in the slab direction at the lower end portion of the copper plate 81 increases rapidly and the lower end portion of the copper plate 81 expands. In the case of the present embodiment, the amount of expansion can be greatly suppressed.
From the above, since the generation of a gap between the copper plate surface and the slab surface can be suppressed and further prevented, the occurrence of corrosion at the lower end of the copper plate can be suppressed. Accordingly, it is possible to provide a continuous casting mold that can produce a cast piece with good quality and can maintain stable quality for a longer period of time than before.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included. For example, the case where the continuous casting mold of the present invention is configured by combining some or all of the above-described embodiments and modifications is also included in the scope of the right of the present invention.
Moreover, in the said embodiment, although the case where the cooling part was each provided in the copper plate lower end part of the long side member and the short side member was demonstrated, as needed, either one of a long side member and a short side member It is also possible to provide a cooling part at the lower end of the copper plate.

(A) is a rear view of the long side member of the casting mold for continuous casting according to the first embodiment of the present invention, and (B) is a cross-sectional view taken along the line aa in FIG. (A) is the elements on larger scale of the lower end part of the long side member, (B) is bb arrow sectional drawing of FIG. 2 (A). (A) is explanatory drawing of the surface temperature analysis result of the same long side member, (B) is explanatory drawing of the displacement amount analysis result of the same long side member. (A) is a rear view of the long side member of the casting mold for continuous casting according to the second embodiment of the present invention, and (B) is a sectional view taken along the line cc of FIG. 4 (A). (A) is the elements on larger scale of the lower end part of the same long side member, (B) is dd arrow sectional drawing of FIG. 5 (A). (A) is explanatory drawing of the surface temperature analysis result of the same long side member, (B) is explanatory drawing of the displacement amount analysis result of the same long side member. (A) is a rear view of the long side member of the casting mold for continuous casting according to the conventional example, and (B) is a cross-sectional view taken along the line ee of FIG. 7 (A). (A) is an explanatory view of the continuous casting method, (B) is an explanatory view of the copper plate surface of the continuous casting mold after the slab manufacturing, (C) is a shape change of the copper plate of the continuous casting mold during continuous casting. It is explanatory drawing shown.

Explanation of symbols

10: Long side member, 11: Water guide groove, 12: Copper plate (cooling plate), 13: Mounting means, 14: Back plate (support member), 15: Water supply unit, 16: Drainage unit, 17: Drainage port, 18: O-ring, 19: cooling section, 20: communication section, 21: cooling water flow path, 22: communication groove, 23: lid, 24: cooling water inflow section, 25: cooling water adjusting plate (partition member), 26: screw, 27: Claw part, 30: Long side member, 31: Copper plate (cooling plate), 32: Cooling water passage (cooling part), 33: Water guide groove, 34: Lid, 35: Cooling water supply path, 36: Lid, 37 : Cooling water discharge path, 38: Discharge port, 39: Cover

Claims (6)

A cooling plate provided with a number of water guide grooves on the back surface, and a support member fixed to the back surface side of the cooling plate by an attaching means via an O-ring surrounding the water guide groove, provided on the support member In a continuous casting mold that cools the cooling plate by flowing cooling water to the water guide grooves through the water supply unit and the drainage unit,
A continuous casting mold, wherein the cooling plate is provided with a cooling part below the O-ring located at the lower end. 2. The continuous casting mold according to claim 1, wherein the cooling part is configured by a cooling water flow path connected to the water supply part and a lower end part of each water guide groove through a communication part. Continuous casting mold. The continuous casting mold according to claim 2, wherein a partition member that divides the communication portion into two stages in the depth direction is disposed in the communication portion, and cooling water that has flowed in from the water supply portion is supplied to the partition member. A continuous casting mold characterized in that the casting mold is lowered to the lower side of the O-ring located at the lower end along the cooling water flow path and then raised to flow into the water guiding groove. 2. The continuous casting mold according to claim 1, wherein the cooling portion is a cooling water passage provided across the width direction of the cooling plate. 5. The continuous casting mold according to claim 4, wherein the cooling water passage is disposed at a cooling water supply passage communicating with the water supply portion and a width direction end portion of the cooling plate, and discharging the cooling water communicating with the drainage portion. A casting mold for continuous casting, characterized in that it is in communication with a path. The continuous casting mold according to any one of claims 1 to 5, wherein a lower end position of the cooling portion is within a range of 20 mm upward from a lower end position of the cooling plate. template.

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