CN118976783A - A method for controlling defects of thick plate narrow surface double drums and a device for continuous casting of ultra-thick slabs - Google Patents
A method for controlling defects of thick plate narrow surface double drums and a device for continuous casting of ultra-thick slabs Download PDFInfo
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- CN118976783A CN118976783A CN202411055195.XA CN202411055195A CN118976783A CN 118976783 A CN118976783 A CN 118976783A CN 202411055195 A CN202411055195 A CN 202411055195A CN 118976783 A CN118976783 A CN 118976783A
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- 238000000034 method Methods 0.000 title claims abstract description 33
- 230000007547 defect Effects 0.000 title claims abstract description 32
- 238000009749 continuous casting Methods 0.000 title claims abstract description 18
- 238000005096 rolling process Methods 0.000 claims abstract description 114
- 238000010438 heat treatment Methods 0.000 claims abstract description 73
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 30
- 239000010959 steel Substances 0.000 claims abstract description 30
- 238000002791 soaking Methods 0.000 claims abstract description 16
- 230000008569 process Effects 0.000 claims abstract description 11
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 67
- 229910052802 copper Inorganic materials 0.000 claims description 67
- 239000010949 copper Substances 0.000 claims description 67
- 208000029154 Narrow face Diseases 0.000 claims description 54
- 230000009467 reduction Effects 0.000 claims description 14
- 238000010079 rubber tapping Methods 0.000 claims description 3
- 238000007789 sealing Methods 0.000 claims description 3
- 238000009966 trimming Methods 0.000 abstract description 7
- 238000004519 manufacturing process Methods 0.000 description 8
- 230000007246 mechanism Effects 0.000 description 8
- 238000001816 cooling Methods 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 229910052751 metal Inorganic materials 0.000 description 7
- 238000005266 casting Methods 0.000 description 4
- 238000007711 solidification Methods 0.000 description 4
- 230000008023 solidification Effects 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910000742 Microalloyed steel Inorganic materials 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000013067 intermediate product Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
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- 238000005299 abrasion Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
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- 230000006835 compression Effects 0.000 description 1
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- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000005058 metal casting Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
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- 238000005507 spraying Methods 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/38—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling sheets of limited length, e.g. folded sheets, superimposed sheets, pack rolling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/72—Rear end control; Front end control
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/74—Temperature control, e.g. by cooling or heating the rolls or the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
- B21B45/004—Heating the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
- B22D11/0406—Moulds with special profile
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/14—Plants for continuous casting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/38—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling sheets of limited length, e.g. folded sheets, superimposed sheets, pack rolling
- B21B2001/386—Plates
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Metal Rolling (AREA)
Abstract
The application provides a thick plate narrow surface double-drum defect control method and an ultra-thick plate blank continuous casting device, comprising the following steps: producing a thick slab with a narrow surface having a convex structure; adopting a four-section heating process to process a thick plate blank with a narrow surface having a convex structure; rough rolling a thick plate blank with a narrow surface having a convex structure to obtain an intermediate blank; finish rolling the intermediate blank to obtain a target steel plate; the method comprises the steps of processing a thick plate blank with a narrow surface having a convex structure by adopting a four-section heating process, wherein the thick plate blank with the narrow surface having the convex structure comprises a preheating section, a heating section I, a heating section II and a soaking section; wherein, the thick plate blank with the rough rolling narrow surface having the convex structure comprises a first stage longitudinal rolling; performing cross rolling in the second stage; longitudinal rolling in the third stage; wherein the finish rolling intermediate billet comprises a fourth stage longitudinal rolling. The depth of the double-drum-shaped middle drum seam of the thick plate blank after rolling can be made shallow by producing the thick plate blank with the narrow surface having the convex structure and combining four sections of heating processes, rough rolling and finish rolling processes, so that the trimming amount of the steel plate is reduced, and the yield of the thick plate is improved.
Description
Technical Field
The application belongs to the technical field of metal casting, and particularly relates to a thick plate narrow surface double-drum defect control method and an extra-thick plate blank continuous casting device.
Background
The double drum deformation is a defect that occurs at the edge portion in the rolling process of the extra thick slab and is parallel to the rolling direction. The defects are positioned on the narrow surface of the steel plate, the narrow surface of the steel plate is double-drum, and the drum seam depth range of the middle part of the narrow surface of the rolled steel plate caused by the double-drum defects is 30-80 mm. In the actual production process, trimming is needed to be carried out at the deepest position of the drum seam, so that the yield and the production efficiency of the thick plate are reduced, and huge economic loss is brought to enterprises. Therefore, eliminating the double drum defect is an important aspect of improving the yield of thick plates.
Disclosure of Invention
Therefore, the technical problem to be solved by the application is to provide the thick plate narrow-face double-drum defect control method and the extra-thick plate blank continuous casting device, which can reduce the depth of the narrow-face double-drum seam after thick plate blank rolling, reduce the trimming amount of the steel plate and improve the yield of the thick plate.
In order to solve the above problems, the present application provides, on the one hand, a method for controlling a narrow-face double-drum defect of a thick plate, comprising:
Producing a thick slab with a narrow surface having a convex structure;
adopting a four-section heating process to process a thick plate blank with a narrow surface having a convex structure;
Rough rolling a thick plate blank with a narrow surface having a convex structure to obtain an intermediate blank;
Finish rolling the intermediate blank to obtain a target steel plate;
wherein, the thickness of the thick slab with the narrow surface having the convex structure is 300 mm-600 mm, and the convex height of the thick slab with the narrow surface having the convex structure is 5 mm-50 mm.
Optionally, the four-section heating process is adopted to process the thick plate blank with the narrow surface having the convex structure, and the method comprises the following steps:
The heating narrow surface of the preheating section is provided with a thick slab with a convex structure;
Heating a section of thick plate blank with a heating narrow surface having a convex structure;
heating a thick slab with a convex structure on the narrow surface of the second section of heating;
The heat equalizing section heats a thick plate blank with a narrow surface having a convex structure.
Optionally, when a thick plate blank with a narrow surface having a convex structure is processed by adopting a four-section heating process, placing the thick plate blank with the narrow surface having the convex structure into a heating furnace for heating;
Wherein, the furnace atmosphere temperature of the preheating section is 1000 ℃ to 1100 ℃, the furnace atmosphere temperature of the heating section is 1080 ℃ to 1180 ℃, the furnace atmosphere temperature of the heating section is 1150 ℃ to 1250 ℃, and the furnace atmosphere temperature of the soaking section is 1180 ℃ to 1230 ℃;
Wherein the heating rates of the preheating section, the first heating section, the second heating section and the soaking section are all more than 15min/cm;
Wherein the soaking time of the soaking section is more than 45min;
Wherein, after the thick plate blank with the narrow surface having the convex structure is processed by adopting a four-section heating process, the tapping temperature is 1150-1210 ℃, the temperature difference between the upper surface and the lower surface is below 15 ℃, and the temperature difference between the core surface is below 25 ℃.
Optionally, the rough rolling narrow surface has thick plate blank of evagination structure, includes:
longitudinal rolling in the first stage;
Performing cross rolling in the second stage;
and (3) longitudinal rolling in the third stage.
Optionally, the first stage is longitudinally rolled for 1-4 times, the second stage is transversely rolled for 2-10 times, and the third stage is longitudinally rolled for 3-8 times.
Optionally, the first-pass cross rolling and the second-pass cross rolling in the second-stage cross rolling are heated for 1-2 min.
Optionally, in the third stage of longitudinal rolling, the reduction rate of at least two passes is greater than 15%.
Optionally, finish rolling the intermediate blank, comprising:
And a fourth stage of longitudinal rolling.
Optionally, the number of finish rolling passes is ten or less, and the reduction rate of each pass is controlled to be 13.5% or less.
In another aspect of the present application, there is provided an ultra-thick slab continuous casting apparatus for producing a thick slab having a narrow face with a convex structure of any one of the above;
The ultra-thick slab continuous casting apparatus includes a mold including a pair of wide-face copper plates each extending in one direction and installed to face each other in a direction intersecting the extending direction, and a pair of narrow-face copper plates each extending to intersect the wide-face copper plates and installed to face each other, thereby sealing a portion between the pair of wide-face copper plates to form an inner space where solidified molten steel is formed into a thick slab;
The narrow-face copper plate is provided with a first working face and a second working face on one side close to the thick plate blank, two second working faces are arranged, one second working face is arranged on one side of the first working face, the other second working face is arranged on the other side of the first working face, and the first working face is respectively connected with the two second working faces;
The cross section of the first working surface is a concave arc line, the middle point of the concave arc line coincides with the transverse central line of the first working surface, the two second working surfaces are symmetrically arranged by taking the transverse central line of the first working surface as a symmetrical center, and the two second working surfaces are also perpendicular to the wide-surface copper plate.
Advantageous effects
According to the thick plate narrow-face double-drum defect control method and the extra-thick plate blank continuous casting device provided by the embodiment of the invention, through producing the thick plate blank with the narrow face having the convex structure and combining four sections of heating processes, rough rolling and finish rolling processes, the depth of the double-drum middle drum seam of the thick plate blank after rolling can be promoted to be shallow, so that the trimming amount of a steel plate is reduced, and the yield of the thick plate is improved.
Drawings
FIG. 1 is a flow chart of a method of thick plate narrow side double drum defect control according to an alternative embodiment of the present application;
FIG. 2 is a flow chart of a method of thick plate narrow side double drum defect control according to another alternative embodiment of the present application;
FIG. 3 is a schematic diagram of a crystallizer according to an alternative embodiment of the present application;
Fig. 4 is a schematic structural view of a narrow-sided copper plate according to an alternative embodiment of the present application;
Fig. 5 is a schematic view of the structure of a guide support roller according to an alternative embodiment of the present application.
The reference numerals are expressed as:
1. A wide-face copper plate; 2. a narrow-face copper plate; 21. a first work surface; 22. a second work surface; 3. a thick slab; 4. a guide support roller; 41. a first section; 42. and a second section.
Detailed Description
In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.
The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, it being understood that the preferred embodiments described herein are for illustration and explanation of the present invention only, and are not intended to limit the present invention.
Referring to fig. 1 and 2, according to an aspect of the embodiment of the present application, there is provided a method for controlling a narrow-side double-drum defect of a thick plate, which is applied to thick plate rolling production, and the thick plate may be a cast slab with a thickness of 300mm to 600 mm.
Wherein, thick plate production includes: casting blank, namely casting molten steel into a thick plate blank 3; heating, namely uniformly heating the thick plate blank 3 to a proper rolling temperature in a heating furnace; and rolling, namely reducing the thickness of the thick slab 3 and controlling the size, the shape and the performance of the thick slab 3.
Narrow-face double-drum defect of thick plate the control method comprises the following steps:
step S101: a thick slab 3 having a narrow face with a convex structure is produced.
In this case, the molten steel may be condensed in the continuous casting stage to be solidified into the slab 3.
Wherein the slab 3 comprises two opposite broad faces and two opposite narrow faces. The narrow surfaces of the thick slab 3 are two side surfaces which are relatively narrow in the width direction of the thick slab 3.
Specifically, the crystallizer comprises a narrow-face copper plate, and the narrow face of the thick plate blank 3 is molded under the action of the narrow-face copper plate.
The wall surface of the narrow-surface copper plate, which is close to one side of the thick plate blank 3, is a working surface, and the working surface is used for supporting the narrow surface of the solidifying thick plate blank 3 and keeping the shape of the narrow surface; and simultaneously, the cooling and solidification device is also used for conducting heat in the thick plate blank 3 to realize cooling and solidification of the thick plate blank 3.
Specifically, the working face can be recessed towards the direction away from the thick plate blank 3 to form a concave structure, so that the solidified narrow surface of the thick plate blank 3 is in a convex structure, and the depth of the narrow surface double-drum-shaped middle drum seam after the thick plate blank 3 is rolled is reduced.
The working surface is recessed in a direction away from the thick slab 3, and may be recessed in the whole working surface or only in the middle of the working surface. When the middle part of the working surface is recessed, the depth of the narrow-surface double drum-shaped seam of the thick plate blank 3 after rolling can be reduced.
Wherein the middle portion of the working surface may be an area in the width direction of the working surface near the lateral center line of the working surface.
Wherein, the concave area of working face can be smooth curved surface, can avoid the narrow face of thick slab 3 to appear the crackle, can also alleviate the wearing and tearing to the working face when thick slab 3 descends in the continuous casting process simultaneously, prolongs the life of narrow face copper.
Wherein, the dent amount of the working surface can be 5 mm-50 mm. For example, the concave amount of the working face is 5mm, and the convex height of the middle part of the narrow face of the solidified thick plate blank 3 is 5mm; the concave amount of the working surface is 25mm, and the convex height of the middle part of the narrow surface of the solidified thick plate blank 3 is 25mm; the working face is recessed by 50mm, and the height of the middle part of the narrow face of the solidified thick plate blank 3 is 50mm.
Wherein, the thick plate blank 3 is pulled out from the crystallizer and enters a secondary cooling zone. The second cooling area is provided with a guide supporting mechanism and a spraying assembly, so that the thick plate blank 3 can be further cooled, the solidification speed of molten steel is accelerated, and the solid thick plate blank 3 with certain strength and shape is formed as soon as possible.
Step S201: and a thick plate blank 3 with a narrow surface having a convex structure is processed by adopting a four-section heating process.
Wherein, the four-section heating process is adopted to process the thick plate blank 3 with the narrow surface having the convex structure, so as to heat the thick plate blank 3 passing through the secondary cooling area.
In this embodiment, the thick plate blank 3 is heated by a heating furnace.
Specifically, when the thick slab 3 with the narrow surface having the convex structure is heated, four-stage heating process is adopted. The temperature gradient in the thick plate blank 3 can be relatively smaller through the four-section heating process, so that the temperature of the whole casting blank is uniform, the rolling and cutting processes in the subsequent processing process are facilitated, and the processing efficiency and quality are improved.
Step S301: rough rolling the thick plate blank 3 with the narrow surface having the convex structure to obtain an intermediate blank.
Wherein, the thick plate blank 3 with the rough rolling narrow surface having the convex structure is used for primarily reducing the thickness of the thick plate blank 3.
Specifically, the thick plate blank 3 with the rough rolling narrow surface having the convex structure comprises multi-pass large reduction rolling, the thickness of the thick plate blank 3 is rapidly and greatly reduced through the large reduction, coarse grains in an as-cast structure are crushed, and the grains of metal are primarily refined, so that the internal structure of the thick plate is improved, the deformation of the metal in the thickness direction is more uniform, the internal stress and defects caused by the uneven deformation are reduced, the preparation is made for the subsequent finish rolling process, and the improvement of the finish rolling efficiency and the product quality is facilitated.
Step S401: and (5) finish rolling the intermediate blank to obtain the target steel plate.
The intermediate blank is a slab obtained in step S301.
The target steel plate can be a thick plate with a narrow surface to be produced and without double-drum defects or with a shallow double-drum-shaped drum seam.
Wherein the finish rolling intermediate billet is used for precisely controlling the size, shape and properties of the thick slab 3.
Specifically, the finish rolling intermediate billet comprises multiple passes of small reduction rolling, and high-precision control of thickness, width and length of the thick plate can be realized through the small reduction. On the basis of rough rolling, the metal grains are further refined, so that the mechanical property and the comprehensive quality of the thick plate are improved, surface defects such as cracks, pits and the like are reduced, and the surface of the thick plate is smoother and flatter.
It can be understood that in the application, by producing the thick plate blank 3 with the narrow surface having the convex structure and combining four sections of heating processes, rough rolling and finish rolling processes, the depth of the double-drum-shaped middle drum seam of the thick plate blank 3 after rolling can be promoted to be shallow, thereby reducing the trimming amount of the steel plate and improving the yield of the thick plate.
Referring to fig. 2, in the step S201, a thick slab 3 having a narrow surface with a convex structure is processed by four-stage heating process, which includes:
step S2011: the preheating section heats the thick plate blank 3 with a narrow surface having a convex structure.
Wherein, the thick plate blank 3 with the convex structure on the heating narrow surface of the preheating section is carried out in a heating furnace.
Wherein, the furnace atmosphere temperature of the preheating section of the thick plate blank 3 with the narrow surface having the convex structure can be 1000 ℃ to 1100 ℃.
Step S2012: a section of thick plate blank 3 with a narrow heating surface having a convex structure is heated.
Wherein, the heating of a section of thick plate blank 3 with a heating narrow surface having a convex structure is also performed in a heating furnace.
Wherein, the temperature of the hearth atmosphere of the heating section of the thick plate blank 3 with the narrow surface having the convex structure can be 1080-1180 ℃.
Step S2013: and heating the thick plate blank 3 with the two-section heating narrow surface having a convex structure.
Wherein, the heating of the thick plate blank 3 with the two-section heating narrow surface having the convex structure is also performed in the heating furnace.
Wherein, the temperature of the hearth atmosphere of the heating two sections of the thick plate blank 3 with the narrow surface having the convex structure can be 1150-1250 ℃.
Step S2014: the narrow surface of the soaking section is heated by the thick plate blank 3 with a convex structure.
Wherein, the thick plate blank 3 with the outer convex structure on the heating narrow surface of the soaking section is also carried out in a heating furnace.
Wherein, the furnace atmosphere temperature of the soaking section of the thick plate blank 3 with the narrow surface having the convex structure can be 1180-1230 ℃.
It is understood that the preheating section, the first heating section, the second heating section and the soaking section of the thick plate blank 3 with the narrow face having the convex structure are performed in the same heating furnace. In the application, the same heating furnace is used for heating the thick plate blank 3 with the narrow surface having the convex structure in stages, so that the temperature uniformity of the thick plate blank 3 can be ensured, the rolling and cutting processes in the subsequent processing process are facilitated, and the processing efficiency and quality are improved.
In the above steps S2011, S2012, S2013 and S2014, the heating rate of the thick slab 3 having the narrow face with the convex structure is all greater than 15min/cm.
It can be understood that in the application, the thick slab 3 with the narrow surface having the convex structure adopts a four-section heating process, which is beneficial to reducing the internal temperature gradient of the thick slab 3, ensuring more uniform tissue and reducing the performance difference caused by uneven temperature; meanwhile, the heating time can be shortened, the residence time of the thick slab 3 in the heating furnace is reduced, and the reaction time of the surface of the thick slab 3 and the atmosphere in the furnace is reduced, so that the generation of iron scales is reduced; meanwhile, the production efficiency can be quickened, and the energy consumption can be reduced.
In the above step S2014, the soaking time of the soaking section of the thick plate blank 3 having the narrow face with the convex structure is more than 45min.
It can be appreciated that in the present application, it is possible to ensure that the temperature inside the thick slab 3 is uniform, which is helpful to reduce the deformation unevenness and the concentration of internal stress due to the temperature difference in the subsequent rolling process.
In this embodiment, after the step S2014, the tapping temperature of the thick slab 3 is 1150-1210 ℃, and meanwhile, the temperature difference between the upper surface and the lower surface of the thick slab 3 is not more than 15 ℃, and the temperature difference between the core surface of the thick slab 3 is not more than 25 ℃.
Referring to fig. 2, in the step S301, the rough rolling of the thick plate blank 3 having the narrow surface with the convex structure includes:
Step S3011: and (3) longitudinal rolling in the first stage.
In the first-stage longitudinal rolling, the thick slab 3 can be effectively compressed and thinned greatly in the thickness direction, and the thick slab 3 can be plastically deformed.
Wherein, in the first stage of longitudinal rolling, the longitudinal rolling can be carried out for 1-4 times.
Step S3012: and (3) performing cross rolling in the second stage.
Wherein, during the second stage cross rolling, the width of the thick slab 3 can be effectively extended.
Wherein, during the second stage of transverse rolling, the transverse rolling can be carried out for 2 to 10 times.
Step S3013: and (3) longitudinal rolling in the third stage.
In the third-stage longitudinal rolling, the thick slab 3 can be further compressed and thinned greatly in the thickness direction.
Wherein, during the third stage longitudinal rolling, 3-8 passes of longitudinal rolling can be performed.
It can be understood that in the application, when the thick plate blank 3 with the convex structure on the rough rolling narrow surface is rolled, the longitudinal-transverse-longitudinal process is adopted, and the rolling in different directions ensures that the deformation of the thick plate blank 3 is more sufficient and uniform, and the grain refinement and uniform distribution are promoted, thereby reducing the depth of the narrow surface double-drum middle drum seam after the thick plate blank 3 is rolled, reducing the trimming amount of the steel plate and improving the yield of the thick plate.
In this embodiment, during the first stage of longitudinal rolling, one pass is longitudinally rolled; during the second stage of transverse rolling, three passes of transverse rolling are performed; and in the third stage of longitudinal rolling, longitudinal rolling is performed in three passes.
In the step S3012, during the second stage of cross rolling, the first-pass cross rolling and the second-pass cross rolling are heated for 1min to 2min.
Specifically, in the embodiment, during the second stage of cross rolling, the interval between the first pass cross rolling and the second pass cross rolling is 2min.
It can be appreciated that in the application, by setting the interval time between the first-pass cross rolling and the second-pass cross rolling when the second-stage cross rolling is performed, the temperature of the edge part of the thick slab 3 can be reduced, and thus the metal flow of the edge part of the thick slab 3 can be inhibited.
In the step S3013, the reduction in at least two passes during the third-stage longitudinal rolling is greater than 15%.
It can be understood that in the present application, during the longitudinal rolling in the third stage, at least two passes of longitudinal rolling have a larger rolling reduction, so that the thickness of the thick slab 3 can be rapidly and greatly reduced, coarse grains in the as-cast structure are crushed, and the grains of the metal are primarily refined, thereby improving the internal structure of the thick slab, enabling the deformation of the metal in the thickness direction to be more uniform, reducing internal stress and defects caused by the uneven deformation, preparing for the subsequent finish rolling process, and being helpful for improving the efficiency and product quality of finish rolling.
Referring to fig. 2, in the above step S401, the intermediate blank is finish rolled to obtain a target steel sheet, including:
step S4011: and a fourth stage of longitudinal rolling.
The fourth stage of finish rolling is effective in greatly reducing the thickness of the thick slab 3 by compression, and in causing plastic deformation of the thick slab 3.
In finish rolling of an intermediate product obtained by rough rolling, ten passes or less can be performed.
Specifically, in this example, the intermediate product obtained by rough rolling was finish rolled, and then rolled in eight passes.
In step S4011, the reduction rate in each pass is 13.5% or less.
It can be appreciated that in the present application, during the fourth stage of longitudinal rolling, each pass of longitudinal rolling has a smaller reduction ratio, and high precision control over the thickness, width and length of the thick plate can be realized. On the basis of rough rolling, the metal grains are further refined, so that the mechanical property and the comprehensive quality of the thick plate are improved, surface defects such as cracks, pits and the like are reduced, and the surface of the thick plate is smoother and flatter.
In another aspect of the embodiment of the present application, referring to fig. 3 and 4, there is provided an ultra-thick slab casting apparatus for producing a thick slab 3 having a narrow face with a convex structure as any one of the above; the extra-thick slab continuous casting apparatus includes a mold including a pair of wide copper plates 1 and a pair of narrow copper plates 2, the pair of wide copper plates 1 each extending in one direction and being installed to face each other in a direction intersecting the extending direction, the pair of narrow copper plates 2 each extending to intersect the wide copper plates 1, and the pair of narrow copper plates 2 being installed to face each other, thereby sealing a portion between the pair of wide copper plates 1 to form an inner space where solidified molten steel becomes a thick slab 3; the narrow-face copper plate 2 is provided with a first working face 21 and a second working face 22 on one side close to the thick slab 3, two second working faces 22 are arranged, one second working face 22 is arranged on one side of the first working face 21, the other second working face 22 is arranged on the other side of the first working face 21, and the first working face 21 is respectively connected with the two second working faces 22; the cross section of the first working surface 21 is a concave arc, the middle point of the concave arc coincides with the transverse center line of the first working surface 21, the two second working surfaces 22 are symmetrically arranged by taking the transverse center line of the first working surface 21 as a symmetrical center, and the two second working surfaces 22 are also perpendicular to the wide-surface copper plate 1. By arranging the first working surface 21 of the narrow-face copper plate 2, which is in contact with the thick plate blank 3, as a concave structure, the production of the thick plate blank 3 with a narrow-face convex structure can be realized, so that the depth of a double-drum-shaped drum seam of the thick plate blank 3 after rolling can be promoted to be shallow, the trimming amount of a steel plate is reduced, and the yield of the thick plate is further improved; meanwhile, the second working surfaces 22 on two sides of the first working surface 21 are in a straight structure, so that the corners of the thick plate blank 3 produced by the extra-thick plate blank continuous casting device are in a right-angle structure, and cracks on the corners of the thick plate blank 3 during production of micro-alloy steel containing NB, AI and V can be avoided.
Wherein, the super thick slab continuous casting device includes: a ladle storing molten steel refined in a steelmaking process; a tundish which receives molten steel through an injection nozzle connected to the ladle and temporarily stores the molten steel; a mold receiving the molten steel stored in the tundish and primarily solidifying the molten steel into a predetermined shape; a submerged nozzle for supplying molten steel of a tundish to the mold; and a secondary cooling zone provided below the mold for providing water spray cooling to the slab 3 drawn from the mold, helping the slab 3 to solidify rapidly, facilitating the execution of a series of molding processes.
In the embodiment of the application, the crystallizer is used for producing a thick plate blank 3 with a narrow surface having a convex structure and no defects at the corners. The thick plate blank 3 may be a thick plate blank 3 having a thickness of 300mm to 600 mm. When the narrow surface of the thick plate blank 3 has a convex structure, the depth of the double-drum-shaped drum seam of the thick plate blank 3 after rolling is shallower.
Wherein the mold comprises a pair of wide copper plates 1, each of the pair of wide copper plates 1 extending in one direction and being spaced apart from each other in a direction intersecting or perpendicular to the extending direction; and a pair of narrow-face copper plates 2 disposed between the pair of wide-face copper plates 1, the pair of narrow-face copper plates 2 extending in directions intersecting or perpendicular to the wide-face copper plates 1, respectively, and the pair of narrow-face copper plates 2 also being spaced apart from each other in directions intersecting or perpendicular to the extending directions.
Specifically, in the embodiment of the present application, the extending direction of the pair of wide-surface copper plates 1 is perpendicular to the extending direction of the pair of narrow-surface copper plates 2. For example, if the extending direction of the pair of wide copper plates 1 is defined as the X-axis direction, the extending direction of the pair of narrow copper plates 2 is the Y-axis direction, and at this time, the pair of wide copper plates 1 are spaced apart in the Y-axis direction, and the pair of narrow copper plates 2 are spaced apart in the X-axis direction. A pair of wide-face copper plates 1 and a pair of narrow-face copper plates 2 form an inner space for forming a thick slab 3 of solidified molten steel.
Specifically, a pair of wide-surface copper plates and a pair of narrow-surface copper plates are combined to form a crystallizer inner cavity so as to solidify molten steel into a thick plate blank 3.
The short side structure comprises a working surface, wherein the working surface can be a wall surface of the narrow-side copper plate 2 facing the inner space direction side of the crystallizer, and the working surface is used for contacting and solidifying the thick slab 3.
Wherein the working face comprises a first working face 21 and a second working face 22, the first working face 21 and the second working face 22 extending in the height direction of the narrow-face copper plate 2. It is understood that the height direction of the narrow-side copper plate 2 may be the length direction of the thick plate blank 3.
Wherein two second working surfaces 22 are provided, and the two second working surfaces 22 are provided on both sides of the first working surface 21 in the width direction of the narrow-surface copper plate 2 and are respectively connected with the first working surface 21. It is understood that the width direction of the narrow-side copper plate 2 may be the thickness direction of the thick plate blank 3.
Specifically, the first working surface 21 is located in the middle of the narrow-surface copper plate 2, and the second working surface 22 is located at the edge of the narrow-surface copper plate 2. The first working surface 21 is smoothly connected with the two second working surfaces 22, so that the probability of generating double-drum shape defects in the rolling process of the thick slab 3 can be reduced.
The first working surface 21 is recessed toward a direction away from the thick slab 3, so that a concave structure is formed, and a contact part of the solidified thick slab 3 and the first working surface 21 is in a convex structure.
The recess of the first working surface 21 may be 5mm to 50mm. For example, the concave amount of the first working surface 21 is 5mm, and the convex height of the middle part of the narrow surface of the solidified thick plate blank 3 is 5mm; the concave amount of the first working face 21 is 25mm, and the convex height of the middle part of the narrow face of the solidified thick plate blank 3 is 25mm; the concave amount of the first working face 21 was 50mm, and the convex height in the middle of the narrow face of the thick plate blank 3 after solidification at this time was 50mm.
Specifically, the cross section of the first working surface 21 is a concave arc, so that abrasion to the narrow-surface copper plate 2 when the solidified shell descends in the continuous casting process can be reduced, and the service life of the narrow-surface copper plate 2 is prolonged.
Wherein the second working surface 22 is a plane surface, so that the contact part of the solidified thick plate blank 3 and the second working surface 22 is in a straight structure.
Specifically, the second working surface 22 is perpendicular to the wide-surface copper plate 1, so that the super-thick slab continuous casting device can prepare a thick slab 3 with a right-angle corner, and cracks at the corner when the thick slab 3 contains NB, AI and V microalloyed steel are avoided. It is understood that the corner of the thick plate blank 3 may be the thick plate blank 3 corresponding to the included angle formed by the intersection of the wide copper plate 1 and the narrow copper plate 2.
The narrow-face copper plate 2 further comprises a top face and a bottom face, the top face is flush with the upper opening of the crystallizer, and the bottom face is flush with the lower opening of the crystallizer. It will be appreciated that the upper mouth of the mould may be the end of the molten steel entering the interior space of the mould and the lower mouth of the mould may be the end of the slab 3 leaving the interior space of the mould.
The narrow-face copper plate 2 further comprises side faces, wherein the side faces can be wall faces which are in contact with the wide-face copper plate 1, two side faces are arranged, and the two side faces are arranged oppositely.
In some possible embodiments provided by the present application, referring to fig. 5, the continuous casting device for extra thick slabs 3 further comprises a guiding and supporting mechanism, wherein the guiding and supporting mechanism is arranged at the lower opening of the narrow-face copper plate 2; the guide support mechanism comprises a guide support roller 4, the guide support roller 4 comprises a first section 41, the first section 41 comprises two diameter reduction sections, the diameters of the two diameter reduction sections gradually decrease towards each other, so that the roller surface of the guide support roller 4 contacting the thick plate blank 3 presents a concave arc which is the same as the cross section of the first working surface 21, and the thick plate blank 3 of a narrow face convex part formed under the action of the first working surface 21 is supported; the guide support roller 4 further comprises two second sections 42, the two second sections 42 being arranged on both sides of the first section 41 in the axial direction of the first section 41, the first section 41 being connected to the two second sections 42, respectively, the two second sections 42 being cylindrical such that the two second sections 42 are adapted to support the slab 3 of narrow-face flat portion formed under the action of the two second working faces 22. The guiding support mechanism is arranged at the lower opening of the crystallizer to support the thick plate blank 3 pulled out of the crystallizer, so that the narrow surface of the thick plate blank 3 is kept to have a convex structure, and the thick plate blank 3 which is not completely solidified is prevented from deforming; meanwhile, the defects of bulging, sinking and the like of the thick plate blank 3 are reduced, and the surface quality and the internal quality of the thick plate blank 3 are improved.
Wherein, the below of narrow face copper 2 is provided with sprays the district, sprays the district and is provided with the frame, and guide support mechanism installs on the frame.
Specifically, the guide support mechanism includes a guide support roller 4, and the guide support roller 4 may be a foot roller rotatably disposed on the frame.
The guide support roller 4 includes a first section 41 and a second section 42 that are coaxially disposed, two second sections 42 are disposed, the first section 41 is disposed between the two second sections 42, and two ends of the first section 41 are respectively connected with the two second sections 42. Furthermore, it is understood that the guide support roller 4 may also be integrally formed.
Specifically, the first section 41 is substantially of an hourglass shape, the first section 41 comprising two reduced diameter sections, each of which has a diameter that decreases progressively in a direction towards each other, so that the first section 41 can adapt to the middle bulge of the narrow face of the slab 3; the second section 42 is substantially cylindrical, the second section 42 is connected to the end of the reduced diameter section having a large end surface area, and the diameter of the second section 42 is the same as the diameter of the end of the reduced diameter section having a large end surface area, so that the second section 42 can be fitted to the corner of the right angle structure of the thick plate blank 3.
Wherein the length of the first section 41 is the same as the width of the first working surface 21.
Wherein, as one embodiment, the length of the second segment 42 is less than the width of the second working surface 22; as another embodiment, the length of the second segment 42 is the same as the width of the second working surface 22. In this embodiment, the length of the second section 42 is less than the width of the second working surface 22.
Specifically, in this embodiment, the length of the second section 42 is less than 0mm to 20mm of the width of the second working surface 22. The angle temperature of the thick plate blank 3 is low, the hardness is high, and the support is not needed, so that the production cost of the guide support mechanism can be reduced.
In this embodiment, the height of the narrow-face copper plate 2 is 800 mm-1000 mm, the thickness is 35 mm-55 mm when the width is 300 mm-600 mm, the width of the second working face 22 may be 0 mm-150 mm, and the length of the second section 42 may be 0 mm-130 mm.
It will be readily appreciated by those skilled in the art that the above advantageous ways can be freely combined and superimposed without conflict.
The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application. The foregoing is merely a preferred embodiment of the present application, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the technical principles of the present application, and these modifications and variations should also be regarded as the scope of the application.
Claims (10)
1. The method for controlling the narrow-face double-drum defect of the thick plate is characterized by comprising the following steps of:
producing a thick plate blank (3) with a narrow surface having a convex structure;
adopting a four-section heating process to process a thick plate blank (3) with a narrow surface having a convex structure;
rough rolling a thick plate blank (3) with a narrow surface having a convex structure to obtain an intermediate blank;
Finish rolling the intermediate blank to obtain a target steel plate;
Wherein the thickness of the thick plate blank (3) with the narrow surface having the convex structure is 300-600 mm, and the convex height of the thick plate blank (3) with the narrow surface having the convex structure is 5-50 mm.
2. The method for controlling the defects of the thick plate narrow surface and the double drums according to claim 1, wherein the processing of the thick plate blank (3) with the narrow surface having the convex structure by adopting the four-section heating process comprises the following steps:
The heating narrow surface of the preheating section is provided with a thick plate blank (3) with a convex structure;
Heating a thick plate blank (3) with a section of heating narrow surface having a convex structure;
heating a thick plate blank (3) with a convex structure on the narrow surface of the two sections of heating;
And the heating narrow surface of the soaking section is provided with a thick plate blank (3) with a convex structure.
3. The method for controlling the defects of the thick plate narrow surface and the double drums according to claim 2, wherein when a thick plate blank (3) with a narrow surface and a convex structure is processed by adopting a four-section heating process, the thick plate blank (3) with the narrow surface and the convex structure is placed in a heating furnace for heating;
Wherein, the furnace atmosphere temperature of the preheating section is 1000 ℃ to 1100 ℃, the furnace atmosphere temperature of the heating section is 1080 ℃ to 1180 ℃, the furnace atmosphere temperature of the heating section is 1150 ℃ to 1250 ℃, and the furnace atmosphere temperature of the soaking section is 1180 ℃ to 1230 ℃;
Wherein the heating rates of the preheating section, the first heating section, the second heating section and the soaking section are all more than 15min/cm;
Wherein the soaking time of the soaking section is more than 45min;
Wherein, after the thick plate blank (3) with the narrow surface having the convex structure is processed by adopting a four-section heating process, the tapping temperature is 1150-1210 ℃, the temperature difference between the upper surface and the lower surface is below 15 ℃, and the temperature difference between the core surface is below 25 ℃.
4. The thick plate narrow face double drum defect control method according to claim 1, characterized in that the thick plate blank (3) with the rough rolling narrow face having the convex structure comprises:
longitudinal rolling in the first stage;
Performing cross rolling in the second stage;
and (3) longitudinal rolling in the third stage.
5. The method for controlling the narrow-face double-drum defect of the thick plate according to claim 4, wherein the first stage is 1-4 times of longitudinal rolling, the second stage is 2-10 times of transverse rolling, and the third stage is 3-8 times of longitudinal rolling;
wherein the number of passes of the thick plate blank (3) with the rough rolling narrow surface having the convex structure is less than nine passes.
6. The method for controlling the narrow-face double-drum defect of the thick plate according to claim 5, wherein the temperature of the first-pass cross rolling and the second-pass cross rolling in the second-stage cross rolling is kept for 1-2 min.
7. The method for controlling a narrow-face double-drum defect of a thick plate according to claim 4, wherein the reduction ratio of at least two passes in the third-stage longitudinal rolling is more than 15%.
8. The method for controlling a narrow-face double-drum defect of a thick plate according to claim 1, wherein the finish rolling of the intermediate blank comprises:
And a fourth stage of longitudinal rolling.
9. The method for controlling a narrow-face double-drum defect of a thick plate according to claim 8, wherein the number of passes of finish rolling is ten passes or less, and the reduction ratio of each pass is controlled to 13.5% or less.
10. A device for continuous casting of extra thick slabs, characterized by being used for producing thick slabs (3) with a narrow face having a convex structure according to any one of claims 1 to 9;
The extra-thick slab continuous casting apparatus includes a mold including a pair of wide-face copper plates (1) and a pair of narrow-face copper plates (2), the pair of wide-face copper plates (1) each extending in one direction and being installed to face each other in a direction intersecting the extending direction, the pair of narrow-face copper plates (2) each extending to intersect the wide-face copper plates (1), and the pair of narrow-face copper plates (2) being installed to face each other, thereby sealing a portion between the pair of wide-face copper plates (1) to form an inner space of a solidified molten steel thick slab (3);
The narrow-face copper plate (2) is provided with a first working face (21) and a second working face (22) on one side close to the thick plate blank (3), two second working faces (22) are arranged, one second working face (22) is arranged on one side of the first working face (21), the other second working face (22) is arranged on the other side of the first working face (21), and the first working face (21) is connected with the two second working faces (22) respectively;
The cross section of the first working surface (21) is a concave arc line, the middle point of the concave arc line coincides with the transverse center line of the first working surface (21), the two second working surfaces (22) are symmetrically arranged by taking the transverse center line of the first working surface (21) as a symmetrical center, and the two second working surfaces (22) are also perpendicular to the wide-surface copper plate (1).
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411055195.XA CN118976783A (en) | 2024-08-02 | 2024-08-02 | A method for controlling defects of thick plate narrow surface double drums and a device for continuous casting of ultra-thick slabs |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202411055195.XA CN118976783A (en) | 2024-08-02 | 2024-08-02 | A method for controlling defects of thick plate narrow surface double drums and a device for continuous casting of ultra-thick slabs |
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| CN118976783A true CN118976783A (en) | 2024-11-19 |
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