SECTOR-SHAPED SECTION OF CONTINUOUS CASTING MACHINE FOR HEAVY REDUCTION OF SOLIDIFIED TERMINAL OF CONTINUOUSLY CAST SLAB AND HEAVY REDUCTION METHOD THEREOF

Abstract

The present invention provides a sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab and a heavy reduction method. The sector-shaped section of a continuous casting machine comprises an upper frame, a lower frame, an upper driving roller, a lower driving roller, a left driven roller set, a right driven roller set, a screw-down gear and clamping cylinders which are positioned on the sector-shaped section; the clamping cylinders are used for clamping the upper frame and the lower frame and keeping the upper frame and the lower frame at a set interval; the upper driving roller is connected with the screw-down gear; the upper driving roller is connected to the upper frame through a bearing base; the lower driving roller is connected to the lower frame through a bearing base; the left driven roller set and the right driven roller set, are respectively positioned on two sides of the driving rollers; the left driven roller set is used for clamping the cast slab before reduction; the right driven roller set is used for clamping the cast slab after reduction; and the diameter ratio of the driving rollers to the driven rollers is 1.1:1-2:1. The deformation permeability of the present invention is increased, equivalent to the deformation of one rolling pass of a two-roller mill with a relatively large roller diameter, which facilitates improvement on the looseness and segregation of the center area of the continuously cast slab.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of International Patent Application No. PCT/CN2014/087369 with a filing date of Sep. 25, 2014, designating the United States, now pending, and further claims priority to Chinese Patent Application No. 201410325414.1 with a filing date of Jul. 9, 2014. The content of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.

TECHNICAL FIELD

[0002] The present invention relates to the technical field of slab casting, in particular to a sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab and a heavy reduction method thereof.

BACKGROUND OF THE PRESENT INVENTION

[0003] The technology for heavy reduction of the solidified terminal of the continuously cast slabs refers to a process of arranging screw-down rollers at a solidified terminal of a continuously cast slab on a continuous casting line, applying heavy-reduction deformation (5-20 mm to the cast slab when the solid phase rate of the center of the cast slab exceeds 80%, and then performing normal rolling production. The technology can obviously improve the center quality (improve macro-structure, shrink holes, looseness, segregation, etc.) of the continuously cast slabs, and can produce quality extra-thick products with a thickness of over 100 mm at a relatively low compression ratio (1.5-2.5).

[0004] When heavy reduction is applied to the solidified terminal of the continuously cast slab, if the sector-shaped section of a casting machine adopts overall heavy reduction, the contact area obviously increases while 5-7 pairs of casting rollers of the sector-shaped section contact the slab at the same time, followed by the obvious increase in the load, so the strength and rigidity of the sector-shaped section must be greatly enhanced to resist the large load on and large elastic deformation of the sector-shaped section and the segmented roller (or casting roller). The segmented roller is comprised of a roll collar, a core shaft and a middle support bearing base, which greatly increases the dimension and weight of the sector-shaped section, thus causing a series of new problems to the lifting, assembling and maintenance of the sector-shaped section. Besides, the heavy reduction is carried out near the solidified terminal of the continuously cast slab, and the deformation (strain) generated when the multiple pairs of roller of the heavy reduction sector-shaped, section perform small-deformation reduction is of poor permeability, and the strain transmitted to the center area of the continuously casting slab is small, which cannot better help improve the looseness and segregation defects of the center area.

[0005] Therefore, when the soft reduction system of the existing continuous casting machine is employed to perform heavy reduction on the solidified terminal of the sector-shaped section of the continuous casting machine, problems including seriously insufficient strength and rigidity of the sector-shaped section and driving rollers of the continuous casting machine, insufficient bearing capability of the clamping cylinders, difficulties in implementation of the heavy reduction on the solidified terminal, and the trend of cracking in the middle of the cast slab appear.

SUMMARY OF PRESENT INVENTION

[0006] The technical problem to be solved by the present invention is to provide a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab and a heavy reduction method thereof, to overcome defects in the prior art including seriously insufficient strength and rigidity of the sector-shaped section and driving rollers of the continuous casting machine, insufficient bearing capability of the clamping cylinders, difficulties in implementation of the heavy reduction on the solidified terminal and trend of cracking in the middle of the cast slab when the sector-shaped section of the existing continuous casting machine is employed to perform heavy reduction on the solidified terminal.

[0007] To solve the above technical problems, an embodiment of the present invention provides a sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab, comprising an upper frame, a lower frame, an upper driving roller, a lower driving roller, a left driven roller set, a right driven roller set, a screw-down gear and clamping cylinders which are positioned on the sector-shaped section of the continuous casting machine. The clamping cylinders are used for clamping the upper frame and the lower frame and keeping the upper frame and the lower frame at a set interval. The upper driving roller is connected with the screw-down gear. The upper driving roller is connected to the upper frame through an upper bearing base. The lower driving roller is connected to the lower frame through a lower bearing base. The left driven roller set and the right driven roller set are respectively positioned on two sides of the driving rollers. The left driven roller set is used for clamping the cast slab before reduction. The right driven roller set is used for clamping the cast slab after reduction. The diameter ratio of the driving rollers to the driven rollers is 1.1:1-2:1.

[0008] According to the present invention, the opening degrees of the right driven roller set and the driving rollers are identical with the thickness of the cast slab after reduction.

[0009] According to the present invention, the opening degree of the left driven roller set is identical with the thickness of the cast slab before reduction.

[0010] According to the present invention, the driving rollers are integrated and manufactured through an integral forming process.

[0011] To solve the above technical problems, the present invention also provides a method for heavy reduction of a solidified terminal of a continuously cast slab, characterized by comprising the following steps:

[0012] (1) applying a certain pressure to the upper frame via the clamping cylinders such that the opening degree of the left driven roller set is identical with the thickness of the cast slab before reduction, and clamping the cast slab before reduction via the clamping cylinders;

[0013] (2) setting the rolling reduction to 5-20 mm, operating the screw-down gear to drive the driving rollers to apply heavy reduction onto the cast slab and to deform the cast slab;

[0014] (3) adjusting the right driven roller set such that the opening degree thereof equals the interval between the upper and lower driving rollers, and clamping the cast slab after reduction by the right driven roller set.

[0015] In the above solution, the present invention adopts large-diameter integrated driving rollers, the upper frame and the lower frame which have high strength and high rigidity, and clamping cylinders with high bearing capabilities; during implementation of the heavy reduction, the total deformation is the deformation generated when the large-diameter driving rollers perform heavy reduction on the continuously cast slab, not the total deformation usually generated when the heavy reduction is gradually completed by 5-7 pairs of casting rollers of the sector-shaped section one by one.

[0016] The technical solution of the present invention has the following beneficial effects:

[0017] 1. The contact area is reduced during the plastic deformation, and only the large-diameter integrated driving rollers screw down, so the total deformation force is obviously reduced.

[0018] 2. The clamping force added via the clamping cylinders of the sector-shaped section is correspondingly reduced; meanwhile, structural materials and weight added to maintain the strength and the rigidity in the process of implementing the heavy reduction by the upper and lower sector-shaped sections are also reduced.

[0019] 3. The deformation permeability is increased, equivalent to the deformation of one rolling pass of a two-roller mill with a relatively large roller diameter, which facilitates improvement on the looseness and segregation of the center area of the continuously cast slab.

DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a front view of a sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab of an embodiment of the present invention;

[0021] FIG. 2 is a lateral view of a sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab of an embodiment of the present invention; and

[0022] FIG. 3 is a schematic diagram of a heavy reduction method for a sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab of an embodiment of the present invention.

DESCRIPTION OF THE MAIN COMPONENTS

[0023] 1 Screw-down gear: 2; Upper frame; 3: Upper driving roller; 4: Upper bearing base; 5: Lower driving roller; 6: Lower bearing base; 7: Lower frame; 8: Left driven roller set; 9: Right driven roller set; 10: Clamping cylinder; 11: Transmission device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0024] In order to clarify the technical problems to be solved, the technical solution and the advantage of the present invention, the present invention is described in detail below in conjunction with the attached drawings and specific embodiments.

[0025] The present invention provides a sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab and a heavy reduction method thereof to solve problems in the prior art including seriously insufficient strength and rigidity of the sector-shaped section and driving rollers of the continuous casting machine, insufficient bearing capability of the clamping cylinders, difficulties in implementation of the heavy reduction on the solidified terminal, the trend of cracking in the middle of the cast slab when the soft reduction system of the existing continuous casting machine is employed to perform heavy reduction on the solidified terminal of the sector-shaped section.

[0026] As shown in FIG. 1 and FIG. 2, an embodiment of the present invention provides a sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a contnuously cast slab, including an upper frame 2, a lower frame 7, an upper driving roller 3, a lower driving roller 6, a left driven roller set, 8, a right driven roller set 9, a screw-down gear 1 and clamping cylinders 10 which are positioned on the sector-shaped section of the continuous casting machine. The clamping cylinders 10 are used for clamping the upper frame 2 and the lower frame 7 and keeping the upper frame 2 and the lower frame 7 at a set interval. The driving rollers and the driven rollers are driven to rotate by a transmission device 11, thus driving the cast slab to move forward. The upper driving roller 3 is connected with the screw-down gear 1. The upper driving roller 3 is connected to the upper frame 2 through an upper bearing base 4. The lower driving roller 5 is connected to the lower frame 7 through a lower bearing base 6. The left driven roller set 8 and the right driven roller set 9 are respectively positioned on two sides of the driving rollers. The left driven roller set 8 is used for clamping the cast slab before reduction. The right driven roller set 9 is used for clamping the cast slab after reduction. The diameter ratio of the driving rollers to the driven rollers is 1.1:1-2:1.

[0027] The opening degrees of the right driven roller set 9 and the driving rollers are identical with the thickness of the cast slab after reduction. The opening degree of the left driven roller set 8 is identical with the thickness of the cast slab before reduction. The driving rollers are integrated and manufactured through an integral forming process.

[0028] As shown in FIG. 3, the present invention also provides a method for heavy reduction of a solidified terminal of a continuously cast slab, including the following steps:

[0029] (1) applying a certain pressure to the upper frame 2 via the clamping cylinders such that the opening degree of the left driven roller set 8 is identical with the thickness of the cast slab before reduction, and clamping the cast slab before reduction via the clamping cylinders;

[0030] (2) setting the rolling reduction to 5-20 mm, operating the screw-down gear 1 to drive the driving rollers to apply heavy reduction onto the cast slab and to deform the cast slab;

[0031] (3) adjusting the right driven roller set 9 such that the opening degree thereof equals the interval between the upper and lower driving rollers, and clamping the cast slab after reduction by the right driven roller set. In this way, the reduction and deformation are only carried out by the large-diameter integrated driving roller 3, while the right driven rollers 9 on the exit side do not screw down and implement deformation. Such reduction mode is similar to the rolling deformation of the cast slab carried out by the two-roller mill.

[0032] The driving rollers of the present invention are large-diameter integrated driving rollers (namely, not segmented rollers assembled by roll collars, core shafts and middle support bearing bases). Meanwhile, considering the increase in loads when the heavy reduction is implemented, the strength and rigidity of the upper frame 2 and the lower frame 7 of the sector-shaped section are enhanced (by 2-5 times), and the bearing capabilities of the four clamping cylinders 10 are correspondingly enhanced (by 2-5 times).

[0033] In the above solution, the present invention adopts large-diameter integrated driving rollers, the upper frame and the lower frame which have high strength and high rigidity, and clamping cylinders with high bearing capabilities; during implementation of the heavy reduction, the total deformation is the deformation generated when the large-diameter driving rollers perform heavy reduction on the continuously cast slab, not the total deformation usually generated when the heavy reduction is gradually completed by 5-7 pairs of casting rollers of the sector-shaped section one by one.

[0034] The technical solution of the present invention has the following beneficial effects:

[0035] 1. The contact area is reduced during the plastic deformation, and only the large-diameter integrated driving rollers screw down, so the total deformation force is obviously reduced.

[0036] 2. The clamping force added via the clamping cylinders of the sector-shaped section is correspondingly reduced; meanwhile, structural materials and weight added to maintain the strength and the rigidity in the process of implementing the heavy reduction by the upper and lower sector-shaped sections are also reduced.

[0037] 3. The deformation permeability is increased, equivalent to the deformation of one rolling pass of a two-roller mill with a relatively large roller diameter, which facilitates improvement on the looseness and segregation of the center area of the continuously cast slab.

[0038] The above embodiments are just preferable embodiments of the present invention. It should be noted that, for those ordinarily skilled in the art, various improvements and changes can be made on the basis of the principle of the present invention. The improvements and changes shall also fall within the protective scope of the present invention.

Claims

1. A sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab, comprising an upper frame, a lower frame, an upper driving roller, a lower driving roller, a left driven roller set, a right driven roller set, a screw-down gear and clamping cylinders which are positioned on the sector-shaped section of the continuous casting machine, characterized in that the clamping cylinders are used for clamping the upper frame and the lower frame and keeping the upper frame and the lower frame at a set interval; the upper driving roller is connected with the screw-down gear; the upper driving roller is connected to the upper frame through an upper bearing base; the lower driving roller is connected to the lower frame through a lower bearing base; the left driven roller set and the right driven roller set are respectively positioned on two sides of the driving rollers; the left driven roller set is used for clamping the cast slab before reduction; the right driven roller set is used for clamping the cast slab after reduction; and the diameter ratio of the driving rollers to the driven rollers is 1.1:1-2:1.

2. The sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab according to claim 1, wherein the opening degrees of the right driven roller set and the driving rollers are identical with the thickness of the cast slab after reduction.

3. The sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab according to claim 2, wherein the opening degree of the left driven roller set is identical with the thickness of the cast slab before reduction.

4. The sector-shaped section of a continuous casting machine for heavy reduction of a solidified terminal of a continuously cast slab according to claim 3, wherein the driving rollers are integrated and manufactured through an integral forming process.

5. A method for heavy reduction of a solidified terminal of a continuously cast slab, characterized by comprising the following steps: (1) applying a certain pressure to the upper frame via the clamping cylinders such that the opening degree of the left driven roller set is identical with the thickness of the cast slab before reduction, and clamping the cast slab before reduction via the clamping cylinders; (2) setting the rolling reduction to 5-20 mm, operating the screw-down gear to drive the driving rollers to apply heavy reduction onto the cast slab and to deform the cast slab; (3) adjusting the right driven roller set such that the opening degree thereof equals the interval between the upper and lower driving rollers, and clamping the cast slab after reduction by the right driven roller set.

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