Chamfering crystallizer for continuous casting machine

Abstract

The utility model relates to the technical field of continuous casting machine equipment, in particular to a chamfering crystallizer for a continuous casting machine, which comprises a wide copper plate (1). Narrow-surface copper plates (2) are arranged between the adjacent wide-surface copper plates (1); a transition area (5) is arranged on the narrow-surface copper plate (2); a foot roller (10) is arranged on one side of the narrow-face copper plate (2); a foot roller chamfer (101) is arranged on the foot roller (10); the transition area (5) and the foot roller chamfer (101) are respectively propped against a casting blank; casting blank corner cooling is delayed in the transition area, the angle temperature of the thick plate is increased, and therefore the brittleness interval of steel is avoided; the abrasion at the joint of the large-surface area and the chamfering area can be reduced, and the service life of the narrow-surface copper plate is prolonged; chamfer supporting is added to the casting blank through the foot rollers, the stress of the corners of the casting blank is reduced, transverse cracks of the corners during production of the thick plate casting blank are avoided, the thick plate casting blank does not need to be ground in subsequent machining, and the delivery progress and the product quality are guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of continuous casting machine equipment, and in particular to a chamfered crystallizer for a continuous casting machine. Background Art

[0002] During the thick slab continuous casting process, the temperature of the slab in the straightening section is generally controlled at 800°C to 900°C, which is the brittle range III. Within this range, the precipitation of microalloyed carbonitrides along the grain boundaries will pin the grain boundaries, causing the grain boundaries to exhibit significant embrittlement during deformation and other processes. Furthermore, because ferrite is softer than austenite, the distribution of film-like proeutectoid ferrite at the austenite grain boundaries will significantly deteriorate the high-temperature plasticity of the steel structure. Therefore, during the straightening process, slabs cast in the brittle range are prone to corner cracks.

[0003] During the straightening process of the billet, there is a deviation in the arc between the segments due to the different gaps between the rollers. When the U-shaped seat is severely worn, the error in the arc between the segments will be aggravated, which will cause the billet to be subjected to force in the thickness direction. In addition, the inner arc is subjected to tensile stress during the straightening process of the billet, which leads to preferential cracking of the austenite grain boundary, and then the formation and expansion of intergranular cracks, that is, the generation of transverse cracks at the corners of the billet.

[0004] The 300mm thick plate continuous casting slab is highly sensitive to cracks. During production, transverse cracks are present at the corners. In severe cases, the corner cracks are visible to the naked eye. This requires the operation area to grind the slab before shipment, which not only affects the shipment progress, but also causes steel material loss and energy loss. In addition, slabs that are not cleanly ground may cause unplanned production after rolling, seriously affecting product quality.

[0005] After searching, the applicant found that the Chinese patent document with publication number 216151036U disclosed a combination structure of a rectangular billet crystallizer inner water jacket and a crystallizer copper tube on April 1, 2022, and the inner water jacket and the copper tube are assembled in a water-free form; the outer side surfaces of the crystallizer copper tube are evenly distributed with longitudinal copper tube water grooves with rectangular cross-sections, and the inner water jacket of the crystallizer is composed of inner and outer arc plates and two side plates connected by screws; the inner sides of the inner and outer arc plates and the two side plates are respectively evenly distributed with longitudinal water jacket water grooves with rectangular cross-sections, and the width dimension of the water jacket water groove is the same as the width dimension of the copper tube water groove spacing boss, and the width dimension of the water jacket water groove spacing boss is the same as the width dimension of the copper tube water groove, and the water jacket water groove and the copper tube water groove spacing boss are arranged relative to each other; this device also cannot solve the above-mentioned technical problems.

[0006] Therefore, in order to improve or solve at least one of the above problems, it is necessary to optimize the existing crystallizer structure. Utility Model Content

[0007] The purpose of the utility model is to provide a chamfering crystallizer for a continuous casting machine which can avoid corner transverse cracks during the production of 300mm cross-section thick plate continuous casting billets and does not require subsequent grinding of the billets.

[0008] In order to solve the above technical problems, the technical solution adopted by the utility model is: a chamfered crystallizer for a continuous casting machine, comprising a wide-face copper plate; a narrow-face copper plate is provided between adjacent wide-face copper plates; a transition zone is provided on the narrow-face copper plate; a foot roller is provided on one side of the narrow-face copper plate; a foot roller chamfer is provided on the foot roller; the transition zone and the foot roller chamfer are respectively in contact with the ingot.

[0009] Both ends of the foot roller are respectively provided with inclined end surfaces; the foot roller chamfer is arranged between the side surface of the foot roller and the inclined end surface.

[0010] The narrow copper plate includes a first side surface; a mounting frame is provided on one side of the first side surface; and the foot roller is provided on the mounting frame.

[0011] The end of the mounting frame close to the first side surface is provided with a roller sleeve; both ends of the roller sleeve are respectively provided with mounting inclined surfaces; the foot roller is arranged in the roller sleeve; the inclined end surface cooperates with the mounting inclined surface.

[0012] The narrow copper plate includes a large area; both ends of the large area are provided with chamfered areas; and the transition area is provided between the large area and the chamfered areas.

[0013] A cold water trough is provided on the narrow copper plate; the cold water trough is arranged on the side of the narrow copper plate away from the large surface area.

[0014] A deep water trough is provided on the narrow copper plate; the deep water trough is provided on the side of the narrow copper plate away from the chamfered area.

[0015] Water gaps are respectively provided at both ends of the narrow copper plate; the water gaps are arranged on the side surfaces of the narrow copper plate.

[0016] The angle between the large surface area and the chamfered area is 150°; the angle between the chamfered area and the side of the narrow surface copper plate is 60°; two narrow surface copper plates are arranged between the wide surface copper plates; the narrow surface copper plates are provided with sides of the large surface area facing each other; the cross-section of the transition zone is an arc, and the arc radius is 16 mm.

[0017] The chamfer angle of the foot roller is 150°; the distance between the axis of the foot roller and the first side surface is 115 mm; the distance between the top surface of the foot roller and the large surface area is 0.2 mm.

[0018] The beneficial effects of this application are:

[0019] 1. The present application sets the chamfers of the large surface area and the chamfered area on the narrow copper plate to 150°, so that the corners of the thick plate ingot are cooled in one dimension, the cooling of the corners of the ingot is delayed, and the angle temperature of the thick plate is increased, thereby avoiding the brittle range of the steel; the transition zone has an arc-shaped cross-section, so that the large surface area and the chamfered area have a smooth transition, thereby reducing the wear at the interface between the large surface area and the chamfered area, and improving the service life of the narrow copper plate. At the same time, the temperature distribution of the ingot in the large surface area and the chamfered area is uniform, which is beneficial to ensuring the quality of the thick plate ingot.

[0020] 2. The present application sets a foot roller in the drawing direction of the narrow copper plate, and both ends of the foot roller are respectively provided with an inclined end surface at 150° to the side of the foot roller; both ends of the roller sleeve are also set to 150°; the chamfer support of the foot roller is increased, and at the same time, the foot roller is 0.2mm lower than the narrow copper plate, which reduces the stress on the corners of the billet and avoids the generation of transverse cracks at the corners during the production of thick plate billets, so that subsequent processing does not require grinding of the thick plate billets, thereby ensuring the shipping progress and product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0022] Figure 1 This is a schematic diagram of the structure of the chamfered crystallizer used in this continuous casting machine.

[0023] Figure 2 This is a schematic diagram of the structure of the narrow copper plate of the chamfered crystallizer used in this continuous casting machine.

[0024] Figure 3 This is a schematic structural diagram of the mounting frame for the chamfered crystallizer used in this continuous casting machine.

[0025] Figure 4 This is a schematic diagram of the structure of the foot roller of the chamfered crystallizer used in this continuous casting machine.

[0026] The marks in the above figure are:

[0027] The following are marked in the figure:

[0028] 1. Wide copper plate,

[0029] 2. Narrow copper plate, 201, first side,

[0030] 3. Large area,

[0031] 4. Chamfer area,

[0032] 5. Transition zone, 6. Cold water trough, 7. Deep water trough, 8. Water gap,

[0033] 9. Roller sleeve, 901. Mounting frame, 902. Mounting ramp,

[0034] 10. Foot roller, 101. Foot roller chamfer, 102. Inclined end face. DETAILED DESCRIPTION

[0035] The following is a further detailed description of the specific implementation methods of the present invention by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and to facilitate its implementation.

[0036] Figure 1 The chamfered crystallizer for the continuous casting machine shown includes a wide copper plate 1; a narrow copper plate 2 is provided between adjacent wide copper plates 1; a transition zone 5 is provided on the narrow copper plate 2; a foot roller 10 is provided on one side of the narrow copper plate 2; a foot roller chamfer 101 is provided on the foot roller 10; the transition zone 5 and the foot roller chamfer 101 are respectively in contact with the ingot.

[0037] The transition zone 5 causes the corners of the thick plate ingot to be cooled in one dimension, delays the cooling of the corners of the ingot, and increases the angle temperature of the thick plate, thereby avoiding the brittle range of the steel; and can reduce the wear at the interface between the large surface area 3 and the chamfered area 4, increase the service life of the narrow copper plate 2, and at the same time make the temperature distribution of the ingot in the large surface area 3 and the chamfered area 4 uniform, which is beneficial to ensuring the quality of the thick plate ingot; the foot roller 10 increases the chamfer support of the ingot, reduces the stress on the corners of the ingot, avoids the generation of transverse cracks at the corners during the production of thick plate ingots, and eliminates the need for grinding the thick plate ingots in subsequent processing, thereby ensuring the shipping progress and product quality.

[0038] Both ends of the foot roller 10 are respectively provided with inclined end surfaces 102 ; the foot roller chamfer 101 is provided between the side surface of the foot roller 10 and the inclined end surface 102 .

[0039] The inclined end face 102 is a frustum structure; the foot roller 10 is a cylindrical structure; the smaller end of the inclined end face 102 is connected to the two ends of the foot roller 10; the foot roller chamfer 101 is 150°, which can provide chamfer support for the billet, reduce the stress on the corners of the billet, and avoid the generation of transverse cracks at the corners during the production of thick plate billets.

[0040] The narrow copper plate 2 includes a first side surface 201 ; a mounting frame 901 is provided on one side of the first side surface 201 ; and the foot roller 10 is provided on the mounting frame 901 .

[0041] The first side surface 201 is the side surface close to the casting direction of the narrow copper plate 2; the mounting frame 901 provides a mounting position for the foot roller 10 and provides stable support for it.

[0042] The end of the mounting frame 901 close to the first side surface 201 is provided with a roller sleeve 9; both ends of the roller sleeve 9 are provided with mounting inclined surfaces 902; the foot roller 10 is arranged in the roller sleeve 9; the inclined end surface 102 cooperates with the mounting inclined surface 902.

[0043] In order to prevent edge cracks and steel leakage from the side drum of the thick plate casting when it leaves the crystallizer, and to ensure that the thick plate casting has certain support when it leaves the crystallizer, a roller sleeve 9 is installed on the foot roller 10 close to the first side surface 201; in order to reduce the stress on the casting, the chamfer angle design must ensure that it is consistent with the copper plate, and the angle is 150°. The retraction amount of the extension section of the 5 foot rollers 10 on the mounting frame 901 and the narrow copper plate 2 is adjusted to 0.2mm, 0.05mm, 0.05mm, 0.05mm, and 0.05mm at a time.

[0044] The narrow copper plate 2 includes a large area 3 ; chamfered areas 4 are provided at both ends of the large area 3 ; and a transition area 5 is provided between the large area 3 and the chamfered area 4 .

[0045] In the production of 300mm cross-section thick plate ingots, the corners of the ingots produced by conventional right-angle crystallizers are cooled by the wide and narrow faces at the same time, and the temperature drops rapidly under two-dimensional cooling; in the present application, the chamfered crystallizer is designed with a chamfered structure at the edge of the narrow copper plate 2, and an obtuse chamfer is added on both sides of the narrow copper plate 2, so that the two-dimensional cooling at the original right-angle position of the edge is changed to nearly one-dimensional cooling, thereby delaying the cooling of the ingot corners and increasing the temperature of the ingot corners. The change in the shape of the ingot corners will cause changes in the flow field at this location. Therefore, when designing the corner angle, it is necessary to ensure that the eddy current state here is minimized as much as possible so that the flow field is in a laminar state as a whole. In the present application, the obtuse chamfer angle is designed to be 150°, and the angle between the chamfered area 4 and the side of the narrow copper plate 2 is 60°. At the same time, compared with the ingots produced by conventional right-angle crystallizers, the chamfered crystallizer can effectively alleviate the stress concentration problem at the corners during the billet drawing process, and has the advantage of physical structure in controlling transverse cracks at the corners;

[0046] Production of 300mm cross-section thick plate ingot The overall thickness of the narrow copper plate 2 in this application is 75mm.

[0047] A cold water trough 6 is provided on the narrow copper plate 2 ; the cold water trough 6 is provided on the side of the narrow copper plate 2 away from the large surface area 3 .

[0048] There are multiple groups of cold water troughs 6. In this application, the height of the cold water troughs 6 under the large surface area 3 is 18 mm, and there are 13 groups. The number of groups of cold water troughs 6 can be increased or decreased according to actual production needs. The cooling water in the cold water troughs 6 can directly contact the narrow copper plate 2, and through the circulation of water, take away the heat on the narrow copper plate 2, thereby realizing rapid cooling of the narrow copper plate 2, helping to ensure the rapid solidification of molten steel during continuous casting, and helping to control the temperature distribution of the billet, preventing the billet from having defects due to excessive temperature. At the same time, the cooling effect of the cold water trough 6 helps to reduce the temperature of the narrow copper plate 2, reducing the thermal stress of the narrow copper plate 2 caused by high temperature, thereby extending the service life of the narrow copper plate 2.

[0049] A deep water trough 7 is provided on the narrow copper plate 2 ; the deep water trough 7 is provided on the side of the narrow copper plate 2 away from the chamfered area 4 .

[0050] In this application, the height of the deep water tank 7 is set to 35 mm. The height of the deep water tank 7 is greater than that of the cold water tank 6 in order to ensure the thickness of the narrow side shell of the billet out of the crystallizer, prevent the risk of bulging on the narrow side, and ensure the quality of the thick plate billet.

[0051] Water gaps 8 are respectively provided at both ends of the narrow copper plate 2 ; the water gaps 8 are provided on the side surfaces of the narrow copper plate 2 .

[0052] In order to ensure the cooling effect of the corners of the thick plate ingot and prevent the risk of bulging and steel leakage due to insufficient cooling at the corners, the water gap 8 is added to the chamfer area 4 of the narrow copper plate 2. The water flow of the narrow copper plate 2 is increased compared with the original, and the water flow of the wide copper plate 1 of the crystallizer remains unchanged. After the water volume of the narrow copper plate 2 is increased, the shrinkage in the width direction of the ingot increases, thereby ensuring the quality of the thick plate ingot.

[0053] The angle between the large surface area 3 and the chamfered area 4 is 150°; the angle between the chamfered area 4 and the side of the narrow copper plate 2 is 60°; two narrow copper plates 2 are arranged between the wide copper plates 1; the narrow copper plates 2 are arranged facing each other with the side surfaces of the large surface area 3; the cross-section of the transition zone 5 is a circular arc, and the arc radius is 16 mm.

[0054] The chamfer angle 101 of the foot roller is 150°; the distance between the axis of the foot roller 10 and the first side surface 201 is 115 mm; the distance between the top surface of the foot roller 10 and the large surface area 3 is 0.2 mm.

[0055] In order to prevent the weakening of cooling, which may cause the shell thickness of the thick plate billet to be unable to withstand the static pressure of the molten steel when it leaves the crystallizer, and thus cause edge cracks and side cracks during production, leading to serious accidents, the process parameters under the chamfered crystallizer are optimized. The flow rate on the narrow side of the crystallizer is set to 660l / min, the taper of the narrow side copper plate 2 is set to 1.2%, and the water volume of the full roller is set to 90l / min.

[0056] After the chamfering mold equipment was completed and the process parameters were optimized, the actual production of 10 heats of narrow copper plate steel was carried out in two castings, with the casting speed of 0.75m / min. The specific production data are shown in Table 5. It can be concluded that the corner temperature at the time of billet discharge is 70-85℃ higher than that of the production in the right-angle crystallizer. At the same time, the billet morphology was observed. The corners of the thick plate billet were normal, there was no side bulge on the narrow side, no obvious defects, and the vibration marks were dense and uniform.

[0057] Table 5 is the actual production data of the chamfered crystallizer used in this continuous casting machine.

[0058]

[0059]

[0060] The specific workflow of this utility model is as follows:

[0061] An obtuse chamfered area 4 is added on each side of the narrow copper plate 2, so that the original two-dimensional cooling at the right angle of the edge is changed to nearly one-dimensional cooling, thereby delaying the cooling of the corners of the ingot and increasing the temperature of the corners of the ingot, thereby avoiding the brittle range of the steel and preventing the generation of transverse cracks at the corners during the production of thick plate ingots;

[0062] A foot roller 10 is provided below the narrow copper plate 2, and the foot roller 10 is located below the narrow copper plate 2 in the direction of billet drawing; chamfer support is added to reduce the stress on the corners of the billet and avoid the generation of transverse cracks at the corners during the production of thick plate billets;

[0063] The cooling water in the cold water trough 6 can directly contact the narrow copper plate 2, and take away the heat on the narrow copper plate 2 through the circulation of water, thereby realizing rapid cooling of the narrow copper plate 2, helping to ensure the rapid solidification of molten steel during continuous casting, and helping to control the temperature distribution of the billet, and preventing defects in the billet due to excessive temperature; a deep water trough 7 is set to ensure the thickness of the billet shell on the narrow side of the billet leaving the crystallizer, and prevent the risk of bulging on the narrow side; a water seam 8 is added to the chamfer area 4 of the narrow copper plate 2, and the water flow rate of the narrow copper plate 2 is increased compared with the original, and the water flow rate of the wide copper plate 1 of the crystallizer remains unchanged. After the water volume of the narrow copper plate 2 is increased, the shrinkage in the width direction of the billet increases, ensuring the cooling effect of the corners of the thick plate billet, and preventing the risk of bulging and steel leakage due to insufficient cooling of the corners.

[0064] The above description of the present invention is provided as an example, in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described method. Any non-substantial improvements made using the method concepts and technical solutions of the present invention, or any application of the above-described concepts and technical solutions of the present invention to other situations without modification, are all within the scope of protection of the present invention.

Claims

1. A chamfered mold for a continuous casting machine, characterized in that: The invention comprises a wide copper plate (1); a narrow copper plate (2) is provided between adjacent wide copper plates (1); a transition zone (5) is provided on the narrow copper plate (2); a foot roller (10) is provided on one side of the narrow copper plate (2); a foot roller chamfer (101) is provided on the foot roller (10); the transition zone (5) and the foot roller chamfer (101) are respectively in contact with the ingot.

2. A chamfered mold for a continuous casting machine according to claim 1, characterized in that: Both ends of the foot roller (10) are respectively provided with inclined end surfaces (102); the foot roller chamfer (101) is provided between the side surface of the foot roller (10) and the inclined end surface (102).

3. A chamfered mold for a continuous casting machine according to claim 2, characterized in that: The narrow copper plate (2) comprises a first side surface (201); a mounting frame (901) is provided on one side of the first side surface (201); and the foot roller (10) is provided on the mounting frame (901).

4. A chamfered mold for a continuous casting machine according to claim 3, characterized in that: The mounting frame (901) is provided with a roller sleeve (9) at the end portion close to the first side surface (201); both ends of the roller sleeve (9) are provided with mounting inclined surfaces (902); the foot roller (10) is arranged in the roller sleeve (9); and the inclined end surface (102) cooperates with the mounting inclined surface (902).

5. A chamfered mold for a continuous casting machine according to any one of claims 3 to 4, characterized in that: The narrow copper plate (2) comprises a large surface area (3); chamfered areas (4) are respectively provided at both ends of the large surface area (3); and the transition area (5) is provided between the large surface area (3) and the chamfered area (4).

6. A chamfered mold for a continuous casting machine according to claim 5, characterized in that: A cold water trough (6) is provided on the narrow copper plate (2); the cold water trough (6) is provided on the side of the narrow copper plate (2) away from the large surface area (3).

7. A chamfered mold for a continuous casting machine according to claim 6, characterized in that: A deep water trough (7) is provided on the narrow copper plate (2); the deep water trough (7) is provided on the side of the narrow copper plate (2) away from the chamfered area (4).

8. A chamfered mold for a continuous casting machine according to any one of claims 6 to 7, characterized in that: Water gaps (8) are respectively provided at both ends of the narrow copper plate (2); the water gaps (8) are provided on the side surfaces of the narrow copper plate (2).

9. A chamfered mold for a continuous casting machine according to claim 8, characterized in that: The angle between the large surface area (3) and the chamfered area (4) is 150°; the angle between the chamfered area (4) and the side surface of the narrow surface copper plate (2) is 60°; two narrow surface copper plates (2) are provided between the wide surface copper plates (1); the narrow surface copper plates (2) are provided with the side surfaces of the large surface area (3) facing each other; the cross section of the transition area (5) is a circular arc, and the arc radius is 16 mm.

10. A chamfered mold for a continuous casting machine according to claim 9, characterized in that: The chamfer angle (101) of the foot roller is 150°; the distance between the axis of the foot roller (10) and the first side surface (201) is 115 mm; and the distance between the top surface of the foot roller (10) and the large surface area (3) is 0.2 mm.

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