WO2013185290A1

WO2013185290A1 - Device and method for casting continuously cast billet having large section

Info

Publication number: WO2013185290A1
Application number: PCT/CN2012/076772
Authority: WO
Inventors: 周守航; 耿明山; 黄衍林; 张西鹏
Original assignee: 中冶京诚工程技术有限公司
Priority date: 2012-06-12
Filing date: 2012-06-12
Publication date: 2013-12-19

Abstract

A device and method for casting a continuously cast billet having a large section. The device comprises an inner crystallizer (1), an outer crystallizer (2), an upper cover mechanism (5), a base mechanism (6) and an ingot guider (10). The base mechanism (6) and the inner part of the upper cover mechanism (5) are communicated with each other and fixed from top to bottom. The outer crystallizer (2) is fixed below the base mechanism (6). The inner crystallizer (1) is fixedly connected to the upper cover mechanism (5). The lower side of the inner crystallizer (1) is inserted into the upper cover mechanism (5) and the base mechanism (6), so that the lower part of the inner crystallizer (1) is arranged at the inner side of the outer crystallizer (2) and concentrically surrounded by the outer crystallizer (2). Liquid metal is filled between the inner crystallizer (1) and the outer crystallizer (2). In the primary stage of casting, the ingot guider (10) is arranged at the bottom of a cavity below the outer crystallizer (2). The liquid metal is cooled by the inner crystallizer and the outer crystallizer to form a solidified cast billet. The cast billet is arranged on the ingot guider (10). Solid cast billets having an ultra large section and thick-wall pipe billets having an ultra large section can be produced on the same equipment by replacing inner crystallizers (1) of different forms.

Description

Casting device for large section continuous casting billet and casting method thereof

Technical field

The present invention relates to a casting apparatus for a large-section continuous casting billet and a casting method therefor. Background technique

With the development of petroleum, chemical, wind power, nuclear power and other industries, the demand for large-diameter tubular billets, cylindrical billets, ring billets and large-section high-quality solid ingot billets continues to increase, and traditional ingot forging punching and reaming techniques cannot be satisfied. The demand for quality, efficiency and cost, with the increase of the cross-sectional diameter of the casting, the looseness of the center, the shrinkage of the hole, the segregation, the low yield (50-65%), and the low production efficiency seriously restrict the development of the industry.

However, due to the influence of large-section heat transfer, the internal casting quality and production efficiency of the casting blank are also significantly reduced with the increase of the section diameter. Even if the liquid core soft reduction technology is further increased with the diameter, the round blank surface layer The transmission of the deformation to the center becomes weaker and weaker, so that the solid continuous casting slab having a diameter of 1000 mm or more becomes a forbidden zone that is difficult to pass through continuously casting.

The same is true for the continuous casting tube technology of large-section slabs. The traditional casting technology of continuous casting tubes is mostly horizontal casting method. The center casting hole adopts solid graphite rod with smaller draft angle. Usually, the diameter of the casting tube does not exceed Φ 500 ϋΐ ιι. At the same time, the wall thickness is also thinner than 100mm. As the diameter increases, defects such as impurities, precipitated gases, and segregation during solidification accumulate in the upper portion, and the quality is seriously deteriorated, thus limiting the possibility of horizontal casting. Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a casting apparatus for a large-section continuous casting billet and a casting method thereof, which are suitable for the manufacture of large-sized solid billets and hollow shell blanks.

The above object of the present invention can be achieved by the following technical solutions:

A casting device for large-section continuous casting blank, comprising a special inner crystallizer, an outer crystallizer, an upper cover mechanism, a base mechanism and a starter; the base mechanism and the inner part of the upper cover mechanism communicate with each other, the upper cover mechanism And a base mechanism fixedly connected to the upper and lower sides; an outer crystallizer is fixedly connected under the base mechanism; a special inner crystallizer is fixedly connected to the upper cover mechanism, and a special inner crystallizer is disposed under the The inside of the upper cover mechanism and the base mechanism, the lower portion of the special inner crystallizer is located inside the outer crystallizer, and is disposed concentrically around the outer crystallizer, the inner crystallizer and the outer crystallizer Filled with a molten metal; in the initial stage of pouring, the starter is disposed at the bottom of the cavity below the outer crystallizer, and the molten metal is cooled by the inner and outer crystallizers to form a solidified cast slab, the casting The blank is located on the spindle.

A casting method for a large section continuous casting billet, comprising the steps of:

A. Provide special internal crystallizer, outer crystallizer, upper cover mechanism and base mechanism; base mechanism and inner cover mechanism The parts are connected to each other, the upper cover mechanism and the base mechanism are fixedly connected up and down; the outer crystallizer is fixedly connected under the base mechanism; the special inner crystallizer is fixedly connected to the upper cover mechanism, and the special inner crystallizer The lower portion is disposed inside the upper cover mechanism and the base mechanism such that a lower portion of the special inner crystallizer is located inside the outer crystallizer and is concentrically surrounded by the outer crystallizer;

B. providing a starter and a lifting and lowering rod, wherein the lifting and lowering rod is connected to the bottom of the spindle and driving the spindle to move up and down, and the spindle is disposed at the bottom of the cavity below the outer crystallizer;

C The molten metal is introduced into the upper cover mechanism, so that the molten metal is filled between the special internal crystallizer and the external crystallizer, and the molten metal is cooled by a special internal crystallizer and an external crystallizer to form a blank shell, and simultaneously lifted and lowered. The push rod drives the starter to move up and down, so that the upper and lower relative movement between the shell and the outer mold can play the role of shelling the outer surface of the shell and the outer mold; D. forming with the thickening of the shell Solidified slab.

The features and advantages of the embodiments of the present invention are: combining a special internal crystallizer with an external crystallizer to perform bidirectional cooling on the slab, so that the effective section and wall thickness of the slab cooling and solidification can be greatly increased, thereby It is suitable for the manufacture of large-sized solid slabs and hollow shells, and in addition, embodiments of the present invention can also realize continuous and semi-continuous casting. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some of the present invention. For the embodiments, those skilled in the art can obtain other drawings according to the drawings without any creative work.

1 is a schematic cross-sectional view showing a first embodiment of a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention, which can be used for casting a solid billet;

2 is a schematic cross-sectional view showing a second embodiment of a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention, which can be used for casting a hollow large-section slab;

3 is a second embodiment of a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention, that is, a schematic view of an assembly process of a continuous casting machine component of a hollow large-section billet;

Figure 4 is a partially enlarged plan view showing a second embodiment of a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention; Figure 5 is a partial view showing a second embodiment of a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention; 2 is a schematic view showing a first embodiment of a special internal crystallizer for a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention, that is, a structure of a special internal crystallizer for a solid round billet;

Figure 7 is a second embodiment of a special internal crystallizer of a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention, that is, a structural diagram of a special internal crystallizer for a hollow large-section casting blank;

Figure 8 is a second embodiment of a special internal crystallizer of a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention, that is, Schematic diagram of the assembly process of the hollow internal section slab with the special internal crystallizer;

Figure 9 is a bottom plan view showing the upper cover mechanism of the casting apparatus for large-section continuous casting billet according to the embodiment of the present invention;

Figure 10 is a cross-sectional view taken along line A-0-A of Figure 9;

Figure 11 is a bottom plan view of the base mechanism of the casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention; Figure 12 is a cross-sectional view taken along line B-0-01-B of Figure 11;

Figure 13 is a schematic view showing a process of shrinkage and compression of a super-section continuous casting core of a casting apparatus for a large-section continuous casting billet according to an embodiment of the present invention;

Fig. 14 is a view showing the simulation prediction result of the continuous casting defect of the super large section hollow large section casting blank of the casting apparatus for the large section continuous casting billet according to the embodiment of the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The "large section billet" in this paper includes solid round billets and hollow billets. The particular internal crystallizer 1 of the present invention is characterized in that it can be used to cast solid round billets or to cast hollow billets by replacing the inner mold type on the same machine. Embodiment 1

As shown in FIG. 1 to FIG. 5 and FIG. 9 to FIG. 12, a casting apparatus for a large-section continuous casting blank according to an embodiment of the present invention includes a special inner crystallizer 1, an outer crystallizer 2, an upper cover mechanism 5, Base mechanism 6 and starter 10. The upper cover mechanism 5 and the interior of the base mechanism 6 communicate with each other, and the upper cover mechanism 5 and the base mechanism 6 are fixedly connected up and down, and constitute an annular molten metal pool 3. The outer crystallizer 2 is fixedly connected under the base mechanism 6; the special inner crystallizer 1 is fixedly connected to the upper cover mechanism 5, and the special inner crystallizer 1 is disposed below the base The inside of the cover mechanism 5 and the base mechanism 6 are described such that the lower portion of the special inner crystallizer 1 is located inside the outer crystallizer 2, and is disposed concentrically around the outer crystallizer 2, the special A molten metal is filled between the inner crystallizer 1 and the outer crystallizer 2. In the initial stage of the pouring, the starter 10 is disposed at the bottom of the cavity below the outer crystallizer 2, and the molten metal is cooled by the inner and outer crystallizers 1, 2 to form a solidified cast strand 4, the casting The blank 4 is located on the spindle 10.

In this embodiment, the lower part of the special inner crystallizer 1 is disposed at the inner center of the outer crystallizer 2, and the special inner crystallizer 1 and the outer crystallizer 2 are filled with a molten metal, SP, and the metal liquid is crystallized in a special interior. Between the machine 1 and the outer crystallizer 2 The two crystallizers perform bidirectional cooling, and after cooling, the solidified strand 4 is pulled out from below the two crystallizers. Further, in this embodiment, a special internal crystallizer 1 is combined with the external crystallizer 2 to perform bidirectional cooling on the casting blank 4, so that the effective thickness of the casting blank 4 can be adjusted to be cooled and solidified, so that it can be more suitable. The manufacture of slabs of specifications.

In this embodiment, the special inner crystallizer 1 and the outer crystallizer 2 are fixedly connected together by the upper cover mechanism 5 and the base mechanism 6, so that the inner and outer crystallizers are fixed and concentrically arranged, so that the components are The replacement has become easier and more convenient. In addition, in this embodiment, by replacing different types of internal crystallizers 1, it is possible to realize both the production of super-large-section solid slabs and the production of super-large-section thick-walled tube blanks on the same equipment.

According to an embodiment of the present invention, the starter 10 is a cylindrical spindle 10a having a solid circular cross section, and the special inner crystallizer 1 is an inverted rocket head structure, and the upper cover The mechanism 5, the base mechanism 6, the outer crystallizer 2 and the starter 10 constitute a solid casting casting apparatus. That is to say, the entire rocket head crystallizer of the present embodiment is immersed in the molten metal, and the solid slab 4a is formed under the crystallizer, and the solid slab of different sections can be produced by replacing the rocket heads of different diameters and cone angles. .

The inner crystallizer 1 has an inverted rocket head structure, and the inner crystallizer 1 has a cylindrical body, and the head of the body has a blunt conical shape.

Specifically, referring to Fig. 6, the special internal crystallizer 1 includes a water inlet straight conduit lh, a return water conduit li and a cooling water circuit. The return conduit li is spaced apart from the straight inlet conduit lh, and the return conduit li includes a returning straight conduit lj and an inner crystallizer jacket lk connected up and down, the outer covering of the return conduit li There is a first heat insulating sleeve lg _{; a} cooling water circuit is disposed inside the inner crystallizer 1. Here, the inner mold coat lk is V-shaped, and the cast slab 4 is a solid cast slab 4a.

The cooling water circuit includes a water inlet circuit la, a return water circuit lb and a water hole lc. The water inlet circuit la is located in the straight water inlet pipe lh, the upper end of the water inlet circuit la is the water inlet Id; the gap between the water inlet straight pipe lh and the return water pipe li constitutes the return water a loop lb, the upper end of the return water loop lb is a water return port le; a water hole lc is disposed between the lower end of the water inlet straight conduit lh and the inner crystallizer jacket lk, the water inlet loop la and the return water The loop lb is connected through the water hole lc.

Referring to the direction of the arrow in Fig. 6, the cooling water enters the water inlet circuit la from the water inlet Id, and then flows into the water return circuit lb through the water hole lc, and then flows out from the water return port le. Wherein, the water inlet Id and the water return port are both located at the upper end of the special inner crystallizer 1, and the water hole is located at the lower end of the special inner crystallizer 1, so that the cooling water flows in the special inner crystallizer 1, and the ring can be sufficiently cooled The molten metal in the vicinity of the special internal crystallizer 1 in the molten metal pool 3.

The first heat insulating sleeve lg includes a high temperature refractory tube lm and a high-strength graphite ln, and the high-temperature refractory tube lm is coated on the outside of the return water straight conduit lj, and the high-strength graphite In covers the inner crystal The outside of the jacket lk. In this embodiment, the high-temperature refractory tube lm is disposed on the periphery of the return water straight conduit lj to separate the external high-temperature overheated metal liquid from the return water straight conduit lj. The high-strength graphite In is enclosed outside the inner crystallizer casing lk, and the inner crystallizer casing lk is separated from the molten metal to heat transfer while protecting the inner crystallizer.

The special inner crystallizer 1 has an inner crystallizer flange lf above it, and the special inner crystallizer 1 is fixed to the upper cover mechanism 5 by the inner crystallizer flange If, SP, special The portion of the inner crystallizer 1 below the inner mold flange If position is in the annular molten metal bath 3, and the portion above the inner mold flange If position is outside the annular molten metal bath 3.

Further, the return water conduit li further includes a return water pipe lp, the return water pipe lp is connected to the top of the return water straight pipe lj, and the water return port le is disposed on the return water pipe lp. The inner crystallizer flange If is located at the top of the return water straight conduit lj. Wherein, the return water pipe lp can be directly connected directly to the return water straight pipe lj, for example, welding; or, as shown in Fig. 6, the lower end of the return water pipe lp is connected back to the water flange lq, and the water returning method The blue lq is coupled with the inner crystallizer flange If, and the backwater pipe lp is connected to the return water straight pipe lj.

As shown in FIG. 1 and FIG. 4, the outer crystallizer 2 includes an outer crystallizer outer casing 2a, an outer crystallizer inner sleeve 2b and a crystallizer copper tube 2c which are sequentially spaced from the outside to the inner, and the outer crystallizer inner sleeve 2b and the outer crystallizer casing 2a are connected with a laterally disposed partitioning plate 2d, the inner end of the separating plate 2d is connected to the outer crystallizer inner sleeve 2b, and the outer end is connected to the outer crystallizer casing 2a, and the separating plate 2d can be located outside the crystallizing The inner sleeve 2b is at an intermediate position in the height direction; the outer mold, the outer casing 2b, 2a has a magnetic stirrer 2e, and the electromagnetic stirrer 2e is located above the partition 2d; the outer crystal The water inlet 2f and the water outlet 2g are respectively disposed on the outer casing 2a, the water inlet 2f is located below the partition 2d, and the water outlet 2g is located above the partition 2d; the outer mold inner sleeve 2b is upper, The lower end respectively penetrates the water flow hole 2h _; the outer mold 2 is provided with a second heat insulating sleeve 2i at the junction with the casting blank 4, that is, the second heat insulating sleeve 2i is located inside the outer crystallizer 2.

Wherein, the outer crystallizer 2 can be connected to the base mechanism 6 via an outer crystallizer flange 2j, where the outer crystallizer flange 2j is attached to the top end of the crystallizer copper tube 2c, the outer crystallizer The flange 2j is combined with the second base flange 6g to connect the outer crystallizer 2 to the base mechanism 6. The second insulating sleeve 2i may be high strength graphite. The electromagnetic stirrer 2e is disposed in the outer crystallizer 2 to crush and stir the crystal grains to form a large number of crystal nuclei.

In this embodiment, there is a gap between the outer casing and the outer casing 2b, 2a, and the partitioning plate 2d divides the space between the inner and outer casings 2b, 2a into two separate spaces; the outer mold inner sleeve 2a and the crystallizing There is a gap between the copper tubes 2c. As indicated by the direction of the arrow in Fig. 4, the cooling water enters the outer mold, the gap below the outer casing 2b, 2a from the water inlet 2f, and then flows into the outer crystallizer from the water flow hole 2h at the lower end of the outer mold 2a. The gap between the inner sleeve 2a and the crystallizer copper tube 2c flows into the gap between the inner and outer jackets 2b, 2a through the water flow holes 2h at the upper end of the outer mold 2a, and then flows out from the water outlet 2g. The cooling water flows in the outer crystallizer 2, exchanges heat with the molten metal inside the outer crystallizer 2, and then the hot water flows out from the water outlet 2g. According to an embodiment of the present invention, as shown in FIG. 9 and FIG. 10, the upper cover mechanism 5 includes a door-shaped upper cover case 5a, and the upper cover case 5a is connected to the outer side of the bottom cover by a first upper cover method. Lan 5b is used to connect the base mechanism 6. The inner cavity of the upper cover casing 5a is provided with a heat insulating and thermal insulation lining 5c. The inner cover of the upper cover mechanism 5 is provided with an inner crystallizer perforation 5d, and the upper cover mechanism 5 is axially inserted through a nozzle insertion hole 5e, and the nozzle penetration hole 5e is located in the inner crystallizer. On the outer side of the perforation 5d, a top cover flange 5f is provided at a position corresponding to the inner crystallizer perforation 5d at the top of the upper cover casing 5a for connecting the special inner crystallizer 1. In this embodiment, the special inner crystallizer 1 is fixed to the second upper cover flange 5f through the inner crystallizer perforation 5d, so that the special inner crystallizer 1 and the upper cover mechanism 5 are combined, and the molten metal is discharged from the nozzle. The penetration hole 5e flows into the upper cover mechanism 5, and at the same time, the nozzle penetration hole 5e can be used to observe the liquid level. Here, two uniformly distributed nozzle penetration holes 5e are provided around the inner crystallizer perforations 5d.

At the bottom of the heat insulating and insulating lining 5c, a slag blocking plate 5g is disposed extending from the edge of the inner crystallizer perforation 5d to the outer side in a tangential direction, and the slag blocking plate 5g is distributed in the metal in the annular molten metal molten pool 3. The liquid is separated from the upper scum, as shown in Fig. 9, where there are two slag plates 5g. The upper cover mechanism 5 is axially disposed with a release hole 5h, the release hole 5h is located outside the inner crystallizer perforation 5d, and a cover is disposed at the upper portion of the upper cover case 5a. The heat insulating cover 5i at the upper end of the 5h, the heat insulating cover 5i can prevent the heat in the annular molten metal pool 3 from diffusing from the discharge hole 5h. Here, two uniformly distributed discharge holes 5h are provided around the inner crystallizer perforation 5d, and the discharge holes 5h are used for discharging the gas generated and introduced in the cavity of the annular molten metal 3 during the initial stage of casting and during the casting process. In addition, the release hole can also be used as an observation, a temperature measurement hole, and the like.

As shown in FIG. 10, the heat insulating and heat insulating lining 5c includes a refractory slab 5j and a heat insulating refractory lining 5k, and the heat insulating refractory lining 5k is connected to the bottom of the inner cavity of the upper cover case 5a, The refractory binder 5j is filled between the upper cover casing 5a and the heat insulating refractory lining 5k. When the special inner crystallizer 1 is inserted into the inner crystallizer for 5d, the fire-resistant slab 5j and the heat-insulating refractory lining 5k are respectively surrounded by the upper and lower positions in the portion of the inner mold 1 which is in the upper cover mechanism 5.

As shown in FIG. 11 and FIG. 12, the base mechanism 6 includes a base housing 6a having a concave shape, and a first base method for connecting the upper cover mechanism is connected to the outer side of the top of the base housing. The first base flange and the first upper cover flange 5b are fixedly coupled by a fastening connector, and the upper cover mechanism 5 and the base mechanism 6 are fixedly coupled together, wherein the fastening connection is The piece can for example be a combination of a flange bolt 5m and a flange nut 6j. The base housing 6a is provided with a refractory lining 6c. The central axis of the pedestal mechanism 6 is inserted through the central hole 6d. The bottom of the base housing 6a corresponds to the central hole 6d of the base. A second base flange 6g for connecting the outer crystallizer 2 is provided at the position.

An tangential inner runner 6h is disposed on the upper portion of the base mechanism 6 in a tangential manner with the central hole of the base, and an outer end of the tangential inner runner corresponds to the nozzle insertion hole 5e, and the inner end is The base center hole 6d is in communication.

The lower part of the base mechanism is provided with a variable frequency induction coil 6e at the upper ring of the outer crystallizer, the variable frequency induction coil is wound around the outer side of the base hole 6d, and the coil protection cover 6f is provided outside the variable frequency induction coil 6e. Among them, the sense of frequency The coil 6e and the molten metal may be separated by a refractory lining 6c. In the normal drawing process, the variable frequency induction coil 6e adopts the function of assisting agitation at low frequency, crushing the primary crystal grains, homogenizing the internal and external temperature and outward heat transfer, and transmitting the core of the nucleus to the core. Frequency or intermediate frequency, used for heating and heat preservation of residual molten steel. Further, a magnetic neon magnet 6p may be disposed outside the variable frequency induction coil 6e and inside the coil protective cover 6f.

a slag discharge port 3a is disposed in the axial direction of the base mechanism 6, and the slag discharge port corresponds to the discharge hole 5h, and a slag discharge groove is connected between the slag discharge port and the base center hole 6d. 6i. Here, there are two evenly distributed tangent runners 6h with two evenly distributed slag trenches 6i.

In this embodiment, the molten metal entering the upper cover mechanism 5 enters the base mechanism 6 from the tangent inner runner 6h, and the tangent inner runner 6h changes the molten metal from the vertical direction to the tangential direction along the annular cavity, and the trailing edge annular cavity The body is circularly moved, and the liquid slag floating above the molten metal is blocked by the slag blocking plate 5g on the upper cover mechanism 5 during the rotation of the molten metal, and flows out of the slag discharge port 3a along the slag discharge groove 6i.

In addition, as shown in FIG. 1 and FIG. 2, the base mechanism 6 may be mounted on the steel structure foundation 3b during installation, and the slag storage tray 3c may be placed on the steel structure foundation 3b corresponding to the position of the slag discharge port 3a. The scum discharged from the slag discharge port 3a is caused to fall into the slag storage tray 3c.

The refractory lining 6c includes a high temperature refractory lining 6k, a carbon refractory brick lining 6m and a knotted refractory 6n, and the high temperature refractory lining 6k is disposed at an upper portion of the inner cavity of the susceptor casing 6a, the carbon a refractory brick lining 6m is disposed at a lower portion of the high temperature refractory lining 6k and located around the pedestal center hole 6d, and the knotted refractory 6n is filled between the high temperature refractory lining 6k and the base casing 6a. And located outside the coil cover 6f. That is to say, in the present embodiment, the high-temperature refractory lining 6k and the carbon refractory brick lining 6m are all in contact with the high-temperature metal liquid, and the lower end of the carbon refractory brick lining 6m is adjacent to the outer crystallizer 2, and the variable frequency induction coil 6e is provided. The carbon refractory brick is lined with a 6m outer periphery and protected by a coil protection cover 6f; the high temperature refractory lining 6k and the carbon refractory brick lining 6m form a lining inner working lining, and the base housing 6a and the pedestal inner layer work. The lining is filled between the knotted refractory 6n.

As shown in FIGS. 1 and 5, the casting apparatus further includes a second water cooling system 9, the second water cooling system 9 is connected below the outer crystallizer 2, and the second water cooling system 9 includes an outer water cooling system. The jetting assembly 9a and the secondary cold section foot roller 9e. The outer two-water-cooled jetting assembly 9a includes a plurality of rows of outer two-cold nozzle ring sets 9b disposed along the axial direction of the casting blank 4, and each outer two-cold nozzle ring group 9b has a plurality of outer two water-cooling nozzles uniformly distributed along the outer circumference of the casting blank 9c, a steam recovery tank 9d is provided outside the outer two-water-cooled injection unit 9a. The second cooling section foot roller 9e is disposed between the two outer two water-cooling nozzle ring groups 9b adjacent to each other so that the water jetted from the outer two-water cooling nozzle 9c is sprayed as much as possible to the casting blank 4 without being The cold section foot roller 9e is blocked, and the second cooling section foot roller 9e can be used to hold the red hot slab 4 with the liquid core.

In the present embodiment, the outer two water-cooling nozzles 9c of the outer two-water-cooled jetting assembly 9a are used to continue cooling the outer surface of the slab of the crystallizer, and the outer two-water-cooled jetting assembly 9a includes six rows of outer rows disposed along the length of the slab 4 Two water cooled nozzle ring group 9b, The figure is only shown, the number of nozzles can be 5 to 50 rows depending on the cooling length, and each outer two water-cooled nozzle ring group 9b has a plurality of outer two water-cooling nozzles 9c, and the number of outer two water-cooling nozzles 9c can be as needed and the diameter of the casting blank 4 The size is determined. Here, each of the outer two water-cooled nozzle ring groups 9b has 6 to 12 outer two water-cooling nozzles 9c.

As shown in Fig. 1, the casting apparatus further includes a heated tundish 7 and a casting distributor 8 which distributes the flow of water in the tundish 7 into a flow of 1 to 4 into the The annular metal liquid pool 3 is inside. Further, the tundish 7 may be a tundish with electromagnetic heating, and the bottom of the tundish 7 has a tapping liquid port; the top of the cast pipe distributor 8 has a steel liquid port, and the cast pipe distributor 8 The lower portion may be evenly distributed with 1 to 4 shunt tubes 8a, and the number of the shunt tubes 8a is the same as the number of the nozzle penetration holes 5e of the upper cover mechanism 5, where there are two shunt tubes 8a, BP, where The cast flow distributor 8 distributes the water flow in the tundish 7 into a symmetrical 180° two-flow introduction into the upper cover mechanism 5; of course, the cast flow distributor 8 can also distribute the water flow in the tundish 7 into a first-class, three-stream, as needed. Or three streams or more are introduced into the upper cover mechanism 5.

Below the outer crystallizer 2, a plurality of rows of nip guide rolls 12 are provided for holding the red hot slab 4 with the wick from the special inner crystallizer 1 and the outer crystallizer 2.

The casting device further includes a lifting and lowering push rod 11 connected to the bottom of the starter 10 and driving the starter 10 to move up and down; the starter 10 is a cylindrical starter 10a In the initial state of the pouring, the upper portion of the circular spindle 10a is disposed at the bottom of the circular cavity below the outer crystallizer 2. In the present embodiment, in the initial stage of the pouring, the cylindrical starter 10a seals the bottom of the circular cavity below the outer crystallizer 2. As the casting progresses, the lifting pusher 11 drags the circular guide downward. At the same time, the spindle 10a is periodically vibrated up and down, so that the casting blank shell moves up and down relative to the inner and outer crystallizers, and the purpose of the shell blank shell and the inner and outer crystallizers 1 and 2 is unshelled.

As shown in FIG. 1, the following describes the operation process of the embodiment of the present invention:

(1) Assembling: As shown in Fig. 3 and Fig. 8, the assembly work of each component is completed, and the starter 10 is placed in the lower cavity of the special inner crystallizer 1 and the outer crystallizer 2, and the peripheral gap is treated. Can be cast as needed;

(2) Casting: hang the qualified molten steel above the tundish 7 and open the molten steel water inlet control system. After the molten steel in the tundish 7 reaches 80%, the liquid outlet of the tundish 7 is opened, and the molten steel is from the tundish 7 The tapping liquid ports are respectively introduced into the nozzle penetration holes 5e of the upper cover mechanism 5 of 180 degrees via the casting flow distributor 8, and the molten steel is then rotated by the tangential gates 6h into the round blank casting chamber of the base mechanism 6. Inside, the molten metal moves in a circular motion in the casting cavity, and the scum floating on the molten metal surface separates the steel and the slag by the difference in specific gravity during the rotation, and is separated by the slag blocking plate 5g mounted on the upper cover mechanism 5 Entering the slag discharge groove 6i and discharging it from the slag discharge port 3a;

The molten metal is cooled and solidified by the special inner crystallizer 1 and the outer crystallizer 2 to form a shell, and the shell is passed through the starter 10 while the billet is being pulled down, and the lifter 11 drives the ingot and the billet relative to the crystallizer. 1, 2 do the up and down vibration, the shell and the mold are detached, gradually move downward at the drawing speed, and the shell gradually thickens, forming V-shaped solidification on both sides of the inner and outer crystallizers 1, 2 in the crystallizer. Veneer and core V-shaped liquid core; when the shell pulls out the inner and outer crystallizers, the red hot billet The shell is exposed to the air and enters the second water cooling system 9;

(3) Cooling control: entering the red hot large section slab with the liquid core of the second water cooling system 9, the outer surface is cooled by the outer two water cooling nozzle 9c from the outer crystallizer 2, the temperature gradually decreases, and the liquid core ratio Gradually reduce to the V-shaped bottom to form a solid completely;

(4) Electromagnetic stirring and heating stop pouring: After the superheated metal liquid is injected into the cavity, it is subjected to a special internal crystallizer 1 and an external crystallizer.

The cooling water circuit on the 2 and the cooling temperature of the variable frequency induction coil 6e are lowered, and a weak solidified layer or a supercooled metal layer is formed on the cylindrical inner cavity;

In the normal casting process, the variable frequency induction coil 6e mainly uses a periodic low-frequency alternating magnetic field to stir the supercooled metal layer, and mixes the supercooled molten metal with the liquid at a higher temperature in the middle of the liquid to increase the number of non-uniform cores in the molten metal; In the later stage, the matching speed is gradually reduced until the drawing is stopped. When the upper feeding liquid is only used to supplement the portion equivalent to the riser required for the solidification of the V-shaped liquid core, the operating frequency of the variable frequency induction coil 6e is changed to the power frequency or The intermediate frequency is continuously supplied with power, and at this time, the water-cooled variable frequency induction coil 6e functions as an induction heating holding furnace, and functions as a riser insulation heating effect;

Subsequently, as the liquid core is continuously reduced, the liquid core end gradually enters the crystallizer, the cooling water in the special inner crystallizer 1 is gradually reduced, and the special inner crystallizer 1 is slowly raised until the remaining metal in the variable frequency induction coil 6e The liquid enters the shell completely, and the special internal crystallizer 1 is completely pulled out, and the insulating material is covered over the remaining molten metal until it is completely solidified;

(5) De-spinning: In the normal continuous casting process at the lower end of the complete solidification zone, the solidified steel slab is taken out from the casting system by hot squeezing to realize continuous casting slab; or after casting a certain length continuously, the casting is stopped until the remaining molten metal is completely After solidification (such as the stop casting step in the above (4)), the entire ingot is finally taken out at a time to realize a semi-continuous casting.

In this embodiment, the lifting and lowering push rod 11 drags the spindle ingot 10 and the casting blank and the blank shell to move up and down relative to the inner and outer crystallizers 1, 2, and the outer surface of the shell and the outer crystallizer 2 are shelled, and the billet The shell and the special inner crystallizer 1 move up and down relative to each other, which plays a semi-solid tamping center structure, eliminates the center shrinkage hole, and loosens.

As shown in Figure 13, in the entire squatting cycle of the slab and the shell, the following four stages can be used to describe: As shown in Figure 13 (a), the first stage: the initial state, this is special The inner mold 1 and the solid solid phase below are elongated, and the upper high temperature liquid phase, that is, the high temperature superheated metal liquid 4c is placed in the center V molten pool, in the casting cavity, the high temperature superheated molten metal 4c and the normal cast slab 4 from top to bottom, the supercooled molten metal enriched with a large number of crystal nuclei 4d (solid ratio 0-30%), the first half of the solid two-phase region 1⁄2 (solid ratio 60-90%) and dense High temperature solid phase 4g;

As shown in Figure 13 (b), the second stage: is the first solidification nucleation stage, at this time, the supercooled molten metal 4d (solid ratio 0-30%) enriched in a large number of crystal nuclei entering the central molten pool The heat transfer on the lower side and the side is cooled by the heat transfer of the upper and inner crystallizers 1, forming a lower V-type solid-liquid two-phase region close to the lower solidified body (solid phase 60-90%) and close to the upper V-shape. The upper V-type solid-liquid two-phase region 4f of the crystallizer, the upper V-type solid-liquid two-phase region 4f is also referred to as the second semi-solid two-phase region (solid ratio 30-60%); As shown in Fig. 13 (c), the third stage: for the second solidification nucleation stage, the proportion of the solid phase fraction of the upper and lower V-type solid-liquid two-phase regions 4f, 4e continues to increase, while the intermediate pure liquid phase region Continuously shrinking, the upper and lower solid-liquid two-phase regions tend to merge; as shown in Figure 13 (d), the fourth phase: the semi-solid pressing phase, the distance between the special internal crystallizer 1 and the solid solid phase below 4g Relatively shortened, that is, relying on the relative squeezing motion of the slab 4 and the special internal crystallizer 1, the semi-solid liquid-solid two-phase region in the middle portion is pressed, and the loose pores associated with the two-phase region are compacted, thereby eliminating For the purpose of loosening the shrinkage cavity, the entire motion cycle ends; the distance between the inner crystallizer and the solid solid phase below is pulled again into the next cycle.

In addition, the relative movement between the special inner crystallizer 1 and the lower solid solid phase 4g can be realized by the up and down movement of the drawing mechanism, the upper inner and outer crystallizers 1, 2 together with the base mechanism 6, and the upper cover mechanism 5 Or not; or, by means of a hydraulic vibration mechanism installed between the steel structure foundations 3b, the base mechanism 6 and the inner and outer crystallizers 1, 2 can be moved up and down; or, by the upper cover mechanism 5 The lifting mechanism on the upper inner crystallizer flange If drives the periodic up and down movement of the special inner crystallizer 1. Among them, the blanking mechanism, the hydraulic vibration mechanism and the lifting mechanism are well known to those skilled in the art, and will not be described herein. Embodiment 2

In the present embodiment, the special inner crystallizer 1 is a columnar structure, and the upper cover mechanism 5, the base mechanism 6, the outer crystallizer 2, and the starter 10 constitute a hollow shell casting apparatus. In this embodiment, large-diameter blanks of different wall thickness specifications can be produced by replacing different outer diameter dimensions. details as follows:

Referring to Fig. 7, the special inner crystallizer 1 includes a straight water inlet conduit lh, a return water conduit li and a cooling water circuit. The return conduit li is spaced apart from the straight inlet conduit lh, and the return conduit li includes a returning straight conduit lj and an inner crystallizer jacket lk connected up and down, the outer covering of the return conduit li There is a first heat insulating sleeve lg _{; a} cooling water circuit is disposed inside the inner crystallizer 1. Here, the inner crystallizer jacket lk has a columnar shape, and the cast strand 4 is a hollow shell blank 4b.

Further, the return water straight conduit lj further includes a return water flange 13a, the inner end of the return water flange 13a is connected to the water inlet straight conduit lh, and the outer end is connected to the bottom of the return water straight conduit lj; The inner mold outer casing lk includes an outer sleeve 13b and an outer casing flange 13c connected to the top of the outer sleeve 13b, and an inner end of the outer casing flange 13c is connected to the water inlet straight pipe lh; The special inner crystallizer 1 further includes an inner crystallizer inner sleeve 13d, the inner crystallizer inner sleeve 13d including an inner sleeve 13e and an inner sleeve upper flange 13f connected to the top of the inner sleeve 13e. The inner end of the flange 13f is connected to the inlet straight pipe lh, and the inner sleeve 13e is spaced apart from the inside of the outer sleeve 13b; the return water flange 13a, the outer flange 13c and the inner sleeve The flange 13f is fixedly connected to each other in the upper and lower portions; the lower portion of the inner sleeve 13e is further provided with a partition 13g and an inner sleeve end cover 13h, and the inner sleeve end cover 13h is located below the partition 13g, the partition 13g, The inner end of the inner end cover 13h is connected to the straight inlet pipe lh, and the outer end is connected to the inner sleeve 13e;

The water hole includes a first water hole 13i, a second water hole 13j, a third water hole 13k and a fourth water hole 13m, and the first water hole 13i radially penetrates the lower portion of the water inlet straight pipe lh. The second water hole 13j radially penetrates the lower end of the inner sleeve 13e, and the first and second water holes 13i, 13j are located between the partition plate 13g and the inner sleeve end cover 13h, The third water hole 13k radially penetrates the upper end of the inner sleeve 13e, the third water hole 13k is located above the partition plate 13g, and the fourth water hole 13m extends longitudinally through the return water flange 13a, the outer casing flange 13c and inner sleeve flange 13f.

In the present embodiment, as indicated by the direction of the arrow in Fig. 7, the cooling water enters the inlet straight pipe lh from the water inlet Id, and then enters the outer casing 13b and the inner casing 13e from the first and second water holes 13i, 13j. In the gap between the two, the third water hole 13k enters the gap between the inner casing 13e and the straight water conduit lh, and then flows from the fourth water hole 13m into between the return straight straight pipe lm and the inflow straight pipe lh. The gap then flows out of the water return port le.

As shown in Fig. 5, the second water cooling system 9 of the present embodiment includes an outer two water cooled jetting assembly 9a, a second cold section foot roller 9e and an inner two water cooled jetting assembly 9f. The structure of the outer two-water cold spray unit 9a and the second cold stage foot roll 9e is the same as that of the above-described embodiment, and will not be described in detail herein. The inner water-cooled spray assembly 9f includes a central water spray pipe 9g and a plurality of rows of inner water-cooling nozzle groups 9j disposed axially along the central water spray pipe, and the center water spray pipe 9g passes through the different-diameter joint 9h The nozzle conduit 9i inserted in the straight water conduit lh is connected, the upper end of the nozzle conduit 9i is exposed through the straight inlet conduit lh, and the lower end is located in the straight inlet conduit lh. The upper and lower positions of the inner two water-cooling nozzle groups 9j correspond to the respective two water-cooling nozzle groups 9b.

Further, the central water spout pipe 9g may be communicated with the nozzle duct 9i, and a water amount control switch 9k may be provided at the upper end of the nozzle duct 9i for controlling the amount of water sprayed by the inner water-cooled nozzle group 9j; or, the nozzle duct 9i may be Rotatable setting, the bottom end of the nozzle conduit 9i is provided with a trick. When the inner two-water-cooled nozzle group 9j is required to spray water, the trick is opened to allow the water of the nozzle duct 9i to flow into the central sprinkler 9g. When the water-cooling nozzle group 9j sprays water, the door is closed, and the water of the nozzle duct 9i cannot flow into the center water spout pipe 9g.

The inner two-water-cooled jetting assembly 9f of this embodiment is for continuously cooling the inner walls of the hollow cast tube blanks 4b of the inner and outer crystallizers 1, 2.

The casting device further includes a starter 10 and a lifting and lowering rod 11, the lifting and lowering rod 11 is connected to the bottom of the spindle 10, and drives the spindle 10 to move up and down; the spindle 10 is a circular cylinder The starter 10b, in the initial state of the pouring, Above the annular cylindrical starter 10b is disposed at the bottom of the annular cavity between the special inner crystallizer 1 and the outer crystallizer 2.

The casting device further includes a lifting and lowering push rod 11 connected to the bottom of the starter 10 and driving the starter 10 to move up and down; the starter 10 is a ring-shaped spindle injector 10b, In the initial state of the opening, the upper portion of the annular starter 10b is disposed at the bottom of the annular cavity between the special inner crystallizer 1 and the outer crystallizer 2.

Figure 14 shows the results of a practical case simulation defect prediction analysis of the present invention. The experimental scheme is a semi-continuous casting of hollow shell blanks of outer diameter Φ 1800 ΙΜΙ, wall thickness 500 mm, height 11000 mm, inner diameter Φ ΙΟΟΟΙΜΚ test material Q345R container steel. As shown in Fig. 14, the test results: the casting yield of the slab is more than 90%; the center has no shrinkage defects; the center has a slight loose defect that can be forged and rolled. When the length of the blank is 20000mm, continuous casting can be realized, and the casting yield of the casting blank can reach 95%~98%. Compared with the conventional method, the embodiment of the invention has the following advantages:

1. Since the upper cover mechanism 5, the base mechanism 6 and the special internal mold 1 of the center are used in the embodiment of the present invention, the fixed and concentric replacement of the inner and outer crystallizers 1 and 2 becomes easier and more convenient.

2. Since the embodiment of the present invention uses the two-way cooling of the slab by the inner and outer crystallizers 1, 2, the effective thickness of the slab cooling and solidification can be greatly increased, and the thickness of the cast slab can be nearly doubled.

3. Since the special replaceable special internal crystallizer 1 is adopted in the embodiment of the invention, the flexible internal switching of the hollow tube blank casting and the solid blank casting can be easily realized by replacing the special internal crystallizer 1, and a device is realized. At the same time, solid billets and hollow billets can be produced.

4. Since the tube blank casting system of the embodiment of the invention adopts a second water cooling system for spraying water inside and outside, the conventional mechanism for spraying water on a single outer surface has high cooling strength, the liquid core of the casting blank is short, the product density is high, and the segregation is light. Good quality.

5. Since the solid slab of the embodiment of the present invention adopts a special rocket head special internal crystallizer 1 structure and a special core semi-solid tamping compacting method, the forced rolling center shrinkage hole, looseness, Eliminating the large-section center solidification defects plays a decisive role, and the mechanism is simpler and more effective than the traditional slab surface liquid core soft reduction method.

6. Since the vertical casting blanking method is adopted in the embodiment of the invention, the inconsistency of the upper and lower solidification of the large section is avoided, and the lack of accumulation of impurities or segregation in the upper part ensures the consistency of the quality of the entire casting blank.

7. Since the casting system of the embodiment of the invention adopts a double tangential inner gate structure, the molten metal is rotated from the tangential inner runner 6h into the cavity, thereby avoiding the temperature and solidification inconsistency of the entire section, especially the super-large section casting, and also There is a difference in the specific gravity of the steel slag to separate the steel slag.

8. In the embodiment of the present invention, the slag iron separating baffle mechanism is disposed on the trajectory of the upper cover metal liquid rotation, that is, the slag blocking plate 5g is provided, and the separation and discharge of the dross and the pure metal liquid can be effectively realized. 9. Since the inner and outer crystallizers 1 and 2 of the embodiment of the invention adopt high-strength graphite composite working lining, the utility model can effectively protect the copper sleeve crystallizer, has the lubricating shelling auxiliary function, and can realize the unprotected slag casting. .

10. Since the variable frequency induction coil 6e is provided in the embodiment of the invention, the electromagnetic stirring in the normal production process, the refinement of the crystal grains, and the adjustment of the temperature of the molten metal in the cavity are realized, and the change of the blank blank speed is simultaneously performed. The billet is heated and insulated to shorten the shrinkage and shrinkage of the tail blank, and the important effect of increasing the yield of the billet.

In summary, due to the application of the above measures, the continuous casting of the super-large solid solid billet of the embodiment of the present invention is no longer limited by the section specifications, so that the ultra-large diameter and thick-walled hollow shell continuous casting can be realized, and the inner and outer crystals are realized. The cooling system of the device, the second water cooling system for spraying water on the inner and outer surfaces, the semi-solid phase tamping method, and the heating and heat preservation effect of the variable frequency induction coil tail blank play the role of improving the quality of the casting and increasing the yield.

Other configurations, working principles, and advantageous effects of the present embodiment are the same as those of the first embodiment, and are not described herein again. Embodiment 3

The embodiment of the invention also proposes a casting method for a large-section continuous casting blank, which comprises the steps of:

A, providing a special inner crystallizer 1, an outer crystallizer 2, an upper cover mechanism 5 and a base mechanism 6; the base mechanism and the inside of the upper cover mechanism 5 are in communication with each other, and the upper cover mechanism 5 and the base mechanism 6 are fixedly connected up and down The outer crystallizer 2 is fixedly connected under the base mechanism 6; a special inner crystallizer 1 is fixedly coupled to the upper cover mechanism 5, and a special inner crystallizer 1 is disposed below the upper cover The inside of the mechanism 5 and the base mechanism 6 is such that the lower portion of the special inner crystallizer 1 is located inside the outer crystallizer 2 and is concentrically surrounded by the outer crystallizer 2;

B. The starter 10 and the lifting and lowering rod 11 are provided. The lifting and lowering rod 11 is connected to the bottom of the starter 10, and drives the starter to move up and down. The starter 10 is disposed under the outer mold 2 The bottom of the cavity;

C, the molten metal is introduced into the upper cover mechanism 5, and the molten metal is filled between the special inner crystallizer 1 and the outer crystallizer 2, and the molten metal is formed by cooling of the special inner crystallizer 1 and the outer crystallizer 2. The shell is shelled, and the lifting and lowering rod drives the spindle to move up and down, so that the upper and lower sides of the shell and the outer crystallizer move relative to each other, and the outer surface of the shell and the outer mold are unpacked;

D. As the shell gradually thickens, a solidified strand is formed.

Other further steps and structures of the embodiment may be the same as those of the first embodiment and the second embodiment, and details are not described herein again. The above is only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention without departing from the spirit and scope of the invention.

Claims

claims

1. A casting device for large-section continuous casting billets, characterized in that the casting device includes a special inner mold, an outer mold, an upper cover mechanism, a base mechanism and a spindle starter; the base mechanism and the upper cover The interior of the mechanism is interconnected, and the upper cover mechanism and the base mechanism are fixedly connected up and down; the outer crystallizer is fixedly connected below the base mechanism; the special inner crystallizer is fixedly connected to the upper cover mechanism, and the special inner crystallizer The lower part of the crystallizer passes through the interior of the upper cover mechanism and the base mechanism, so that the lower part of the special inner crystallizer is located inside the outer crystallizer and is concentrically surrounded by the outer crystallizer, so The space between the inner crystallizer and the outer crystallizer is filled with molten metal; in the initial stage of pouring, the ingot is set at the bottom of the cavity below the outer crystallizer, and the molten metal is cooled by the inner and outer crystallizers. A solidified cast slab is formed, which is located on the starter.

2. The casting device for large-section continuous casting slabs according to claim 1, characterized in that the ingot is a circular cylindrical ingot with an annular cross-section, and the special inner crystallizer is The columnar structure, together with the upper cover mechanism, the base mechanism, the outer mold and the annular cylindrical ingot, forms a hollow tube casting device.

3. The casting device for large-section continuous casting billets according to claim 1, characterized in that the ingot is a cylindrical ingot with a solid circular cross-section, and the special inner crystallizer is inverted. The rocket head-like structure, together with the upper cover mechanism, the base mechanism, the outer mold and the cylindrical dummy, constitutes a solid slab casting device.

4. The casting device for large-section continuous casting slabs according to claim 1, characterized in that the special inner crystallizer includes a straight water inlet conduit, a return water conduit and a cooling water circuit; the return water conduit is arranged at intervals around it Outside the water inlet straight conduit, the return water conduit includes a return water straight conduit and an inner crystallizer jacket connected up and down, and the outside of the return water conduit is covered with a first heat insulation jacket; the cooling water loop is provided at the The inside of the crystallizer.

5. The large-section continuous casting billet casting device according to claim 4, characterized in that the inner mold outer jacket is V-shaped, and the casting billet is a solid casting billet.

6. The large-section continuous casting billet casting device according to claim 4, characterized in that the inner mold outer jacket is columnar, and the casting billet is a hollow tube billet.

7. The casting device for large-section continuous casting slabs according to claim 5 or 6, characterized in that the cooling water circuit includes a water inlet circuit, a return water circuit and a water hole; the water inlet circuit is located directly from the water inlet. In the conduit, the upper end of the water inlet loop is the water inlet; the gap between the water inlet straight conduit and the return water conduit constitutes the return water loop, and the upper end of the return water loop is the return water inlet; the water hole is provided in Between the lower end of the water inlet straight conduit and the inner crystallizer jacket, the water inlet loop and the return water loop are connected through water holes.

8. The casting device for large-section continuous casting billets according to claim 5 or 6, characterized in that the first heat insulation jacket includes a high-temperature refractory tube and high-strength graphite, and the high-temperature refractory tube is coated in the Returning to the outside of the straight pipe, the high-strength graphite coats the outside of the inner crystallizer jacket.

9. The casting device for large-section continuous casting slabs according to claim 5 or 6, characterized in that there is an inner mold flange above the special inner crystallizer, and the inner crystallizer passes through the inner crystallizer. The device flange is fixed on the upper cover mechanism;

The return water conduit also includes a return water riser conduit, the return water riser conduit is connected to the top of the return water straight conduit, the return water inlet is provided on the return water riser conduit, and the inner crystallizer flange is located on the return water riser conduit. Water straight to the top of the conduit.

10. The casting device for large-section continuous casting billets according to claim 7, characterized in that the return water straight conduit further includes a return water flange, and the inner end of the return water flange is connected to the water inlet straight conduit. on, the outer end is connected to the bottom of the return straight pipe; the inner crystallizer jacket includes an outer sleeve and an outer flange connected to the top of the outer sleeve, and the inner end of the outer flange is connected to the water inlet straight pipe;

The special inner crystallizer also includes an inner casing of the inner crystallizer. The inner casing of the inner crystallizer includes an inner casing and an inner casing upper flange connected to the top of the inner casing. The inner end of the inner casing upper flange is connected to On the water inlet straight pipe, the inner casing is arranged at intervals inside the outer casing; the return flange, the outer flange and the upper flange of the inner casing are fixedly connected together up and down in sequence; the inner casing is The lower part of the casing is also provided with a partition and an inner casing end cover. The inner casing end cover is located below the partition. The inner ends of the partition and the inner casing end cover are connected to the water inlet straight pipe. The outer ends are all connected to the inner casing;

The water hole includes a first water hole, a second water hole, a third water hole and a fourth water hole. The first water hole radially penetrates the lower part of the water inlet straight conduit, and the second water hole radially penetrates The lower end of the inner casing, and the first and second water holes are located between the partition plate and the inner casing end cover plate, the third water hole radially penetrates the upper end of the inner casing, and the third water hole radially penetrates the upper end of the inner casing. The water hole is located above the partition plate, and the fourth water hole penetrates longitudinally through the return flange, the outer flange and the inner upper flange.

11. The large-section continuous casting billet casting device according to claim 1, characterized in that the upper cover mechanism includes a door-shaped upper cover shell, and the bottom outer side of the upper cover shell is connected with a The first upper cover flange of the base mechanism, the inner cavity of the upper cover shell is built with a thermal insulation lining; the center of the upper cover mechanism is axially provided with an inner crystallizer perforation, and the upper cover The cover mechanism is axially provided with a nozzle penetration hole. The nozzle penetration hole is located outside the inner crystallizer perforation. The top of the upper cover shell is provided with a position corresponding to the inner crystallizer perforation for connecting the Special inner crystallizer

- ~ ^Top method 2

12. The large-section continuous casting billet casting device according to claim 11, characterized in that, at the bottom of the thermal insulation lining, there is a stop extending in a tangential direction from the edge of the inner mold perforation to the outside. Slag plate; The upper cover mechanism is provided with a relief hole axially penetrating through it, the relief hole is located outside the perforation of the inner crystallizer, and there is a seal on the upper part of the upper cover shell covering the upper end of the relief hole. Insulated cover;

The insulating and thermal insulation lining body includes a refractory knotting material and an insulating and refractory lining. The insulating and refractory lining is connected to the bottom of the inner cavity of the upper cover shell. The upper cover shell and the insulating and refractory lining are connected. The refractory knotting material is filled in between.

13. The large-section continuous casting billet casting device according to claim 1, characterized in that the base mechanism includes A concave-shaped base shell, the top outer side of the base shell is connected with a first base flange for connecting the upper cover mechanism, the first base flange and the first upper cover The flange is fixedly connected through fastening connectors, the base shell is provided with a refractory lining, the center of the base mechanism is axially provided with a base center hole, and the bottom of the base shell corresponds to the base. A second base flange for connecting the outer crystallizer is provided at the center hole of the base.

14. The casting device for large-section continuous casting billet according to claim 13, characterized in that, the upper part of the base mechanism is provided with a tangential inrunner arranged tangentially to the center hole of the base, and the tangential inner runner is The outer end of the sprue corresponds to the above-mentioned nozzle penetration hole, and the inner end is connected to the central hole of the base.

15. The casting device for large-section continuous casting slabs according to claim 13, characterized in that, at the lower part of the base mechanism, a variable frequency induction coil is arranged in a ring at the upper part of the outer mold, and the variable frequency induction coil surrounds the outer mold. Outside the center hole of the base, there is a coil protective cover outside the frequency conversion induction coil.

16. The large-section continuous casting billet casting device according to claim 13, characterized in that a slag discharge port is axially provided on the base mechanism, and the slag discharge port corresponds to the above-mentioned relief hole, and A slag discharge ditch is connected between the slag discharge port and the center hole of the base.

17. The casting device for large-section continuous casting slabs according to claim 15, characterized in that the refractory lining body includes a high-temperature refractory lining, a carbon refractory brick lining and knotted refractory material, and the high-temperature refractory lining At the upper part of the inner cavity of the base shell, the carbon refractory brick lining is provided at the lower part of the high-temperature refractory lining and is located around the central hole of the base, and the knotted refractory material is filled in the Between the high-temperature refractory lining and the base shell, and on the outside of the coil protective cover.

18. The casting device of large-section continuous casting billet according to claim 5, characterized in that the casting device further includes a second water cooling system, and the second water cooling system is connected below the outer crystallizer, so The second water-cooling system includes an external secondary water-cooling injection assembly and a secondary cooling section foot roller; the external secondary water-cooling injection assembly includes multiple rows of external secondary cooling nozzle ring groups arranged along the axial direction of the cast slab, and each row of external secondary cooling nozzle ring groups has There are multiple outer water-cooled nozzles evenly distributed along the outer circumference of the cast slab, and a steam recovery box is provided outside the outer water-cooled injection assembly; the foot roller of the secondary cooling section is set between the two adjacent outer water-cooled nozzle ring groups up and down. To hold the red hot slab with liquid core.

19. The casting device for large-section continuous casting slabs according to claim 6, characterized in that the casting device further includes a second water cooling system, and the second water cooling system is connected below the outer crystallizer, so The second water-cooling system includes an outer two water-cooling injection components, an inner two water-cooling injection components and a secondary cooling section foot roller; the outer two water-cooling injection components include multiple rows of external secondary cooling nozzle ring groups arranged along the axial direction of the cast slab, each row of external water-cooling nozzle rings. The secondary cooling nozzle ring group has a plurality of external secondary water-cooled nozzles evenly distributed along the outer circumference of the casting slab, and a steam recovery box is provided outside the external secondary water-cooled injection assembly; the internal secondary water-cooling injection assembly includes a central water spray pipe and a central spray pipe along the center. There are two water-cooled nozzle groups in multiple rows arranged axially in the water pipe. The central water spray pipe is connected to the nozzle conduit inserted in the water inlet straight conduit through the reducing joint, and the upper end of the nozzle conduit passes out. The water inlet straight conduit is exposed, and the lower end is located in the water inlet straight conduit; the secondary cooling section foot roller is arranged between the two outer two water-cooling nozzle ring groups adjacent up and down, for Clamp the red hot billet with liquid core.

20. The casting device for large-section continuous casting slabs according to claim 9, characterized in that a lifting mechanism is provided on the inner mold flange, and the lifting mechanism drives the inner mold to move up and down periodically.

21. The casting device for large-section continuous casting billet according to claim 5, characterized in that the casting device further includes a lifting push rod, the lifting push rod is connected to the bottom of the starter and drives the starter. The spindle moves up and down; the spindle starter is a cylindrical spindle starter. In the initial pouring state, the upper part of the cylindrical spindle starter is arranged at the bottom of the circular cavity below the outer crystallizer.

22. The casting device for large-section continuous casting billets according to claim 6, characterized in that the casting device further includes a lifting push rod, the lifting push rod is connected to the bottom of the starter and drives the starter. The ingot moves up and down; the ingot is a circular cylindrical ingot. In the initial state of pouring, the top of the annular cylindrical ingot is arranged between the special inner crystallizer and the outer crystallizer. the bottom of the annular cavity.

23. The casting device for large-section continuous casting slabs according to claim 1, characterized in that the casting device further includes a heated tundish and a strand distributor, and the strand distributor divides the tundish into The water flow inside is distributed into one to four flows and is introduced into the upper cover mechanism; multiple rows of clamping guide rollers are arranged below the outer crystallizer.

24. A casting method for large-section continuous casting billet, which includes the steps:

A. Provide special inner crystallizer, outer crystallizer, upper cover mechanism and base mechanism; the base mechanism and the upper cover mechanism are interconnected internally, and the upper cover mechanism and the base mechanism are fixedly connected up and down; the outer crystallizer is fixedly connected at Below the base mechanism; a special inner crystallizer is fixedly connected to the upper cover mechanism, and the lower part of the special inner crystallizer is penetrated inside the upper cover mechanism and the base mechanism, so that the special inner crystallizer is The lower part of the inner crystallizer is located inside the outer crystallizer and is concentrically surrounded by the outer crystallizer;

B. Provide a spindle starter and a lifting push rod. The lifting push rod is connected to the bottom of the spindle starter and drives the spindle starter to move up and down. The spindle starter is arranged at the bottom of the cavity below the outer crystallizer;

C. Introduce the molten metal into the upper cover mechanism, and then fill the molten metal between the special inner crystallizer and the outer crystallizer. The molten metal is cooled by the special inner crystallizer and the outer crystallizer to form a shell, and rises and falls at the same time. The push rod drives the starter to move up and down, causing the relative movement between the billet shell and the outer crystallizer to move up and down, which plays the role of deshelling the outer surface of the billet shell and the outer crystallizer;

D. As the billet shell gradually thickens, a solidified cast billet is formed.