A high-efficiency cold-rolled product manufacturing method

Abstract

The present application discloses a method for manufacturing high-efficiency cold-rolled products. The method comprises: performing rough rolling on the provided slab according to the first head and tail short stroke value, and in the rough rolling process, controlling the rough rolling vertical roller to squeeze the head and tail of the slab more than the middle section of the slab according to the first head and tail short stroke value of the rough rolling vertical roller, so as to obtain an intermediate billet that meets the preset size specification; the preset size specification is that the width of the head and tail of the intermediate billet are both less than the width of the middle section; finishing rolling the intermediate billet to obtain a hot-rolled coil, and sequentially performing pickling and cold continuous rolling, bell furnace annealing, flattening by a flattener, finishing and coiling or cutting on the hot-rolled coil to obtain a cold-rolled product. According to the embodiment of the present application, the problem of low yield and production efficiency of cold-rolled products caused by hemming can be solved.

Description

Technical Field

[0001] The present application belongs to the field of rolling process technology, and in particular, relates to a high-efficiency cold-rolled product manufacturing method. Background Art

[0002] In the process of steel smelting, the raw materials for steelmaking are first smelted into slab materials. After that, the slab materials are subjected to rough rolling and finish rolling to obtain hot-rolled coils that meet product standards in terms of thickness, width, surface quality and plate shape. The hot-rolled coils are transported to the cold rolling unit, where the oxidized iron scale on the surface of the intermediate slab is removed by pickling and cold rolling, so that the thicker hot-rolled coils are rolled into thinner chilled coils. The chilled coils also need to be annealed to eliminate the work hardening of the chilled coils caused by cold rolling.

[0003] Hood furnace annealing is a common annealing method used in domestic cold-rolled sheet mills. The main process of an existing hood furnace annealing is to flip the vertical chilled coil into a horizontal state through a steel turning machine, and then use a vertical clamp to put the horizontal chilled coil into the hood furnace. The chilled coils in the hood furnace are separated by the convection plate in the furnace for annealing.

[0004] However, during the bell-type furnace annealing process, the inner and outer rings of the chilled coil often adhere together due to the extrusion of the bell-type furnace convection plate, resulting in hemming at the edge of the chilled coil. The hemming will affect the quality of the final finished steel coil, so it is necessary to manually cut off the hemming part before the next step of annealing, which affects the yield rate and production efficiency of the cold-rolled product. Summary of the invention

[0005] The embodiment of the present application provides a high-efficiency cold-rolled product manufacturing method, which can solve the problems of low yield and production efficiency of cold-rolled products produced by existing bell-type furnaces.

[0006] Specifically, an embodiment of the present application provides a high-efficiency cold-rolled product manufacturing method, the method comprising:

[0007] The provided slab is rough rolled according to the first head and tail short stroke value. During the rough rolling process, according to the first head and tail short stroke value of the rough rolling vertical roller, the rough rolling vertical roller is controlled to squeeze the head and tail of the slab more than the middle section of the slab, so as to obtain an intermediate slab meeting a preset size specification; the preset size specification is that the width of the head and tail of the intermediate slab is less than the width of the middle section;

[0008] The intermediate billet is finish-rolled to obtain a hot-rolled coil, and the hot-rolled coil is sequentially pickled and cold-rolled, annealed in a bell furnace, leveled by a leveler, and leveled and divided into coils or cut into plates to obtain a cold-rolled product.

[0009] In some embodiments, the first head-to-tail short stroke value ranges from -11 to 8 mm.

[0010] In some embodiments, before rough rolling the provided slab according to the first head and tail short stroke values, the method further includes:

[0011] With respect to a plurality of target positions of the head and tail of the slab, when the plurality of target positions are in different thickness ranges, a first head and tail short stroke value of the roughing vertical roll is set.

[0012] In some embodiments, the first head-tail short stroke value includes a first head short stroke value, and when the target position is on a first side, the first head short stroke value ranges from -5 to 3 mm, and the first side is a side of the head of the slab away from the tail;

[0013] When the distance between the target position and the first side is a preset distance, the short stroke value of the first head is in the range of 2 to 8 mm.

[0014] In some embodiments, the first head-tail short stroke value includes a first tail short stroke value, and when the target position is on the second side, the tail short stroke value ranges from -11 to -5 mm, and the second side is the side of the tail of the slab away from the head;

[0015] When the distance between the target position and the first side is a preset distance, the range of the first tail short stroke value is -4 to 0 mm.

[0016] In one embodiment, before rough rolling the provided slab according to the first head and tail short stroke values, the method further comprises:

[0017] Adjusting the original grade of the slab to the grade of the slab;

[0018] Determine whether to perform rough rolling on the provided slab according to the first head and tail short stroke values ​​based on the slab brand.

[0019] In the present application, only by optimizing the head and tail short stroke values, the width of the head and tail of the intermediate billet is controlled to be smaller than the width of the middle section during the rough rolling process. Therefore, on the chilled coil that inherits the width of the intermediate billet, the width of the head and tail is also smaller than the width of the middle section. As a result, during the annealing process of the chilled coil in the hood furnace, the convection plate in the furnace will not squeeze the chilled coil and cause the edge of the chilled coil to form a rim. This avoids the process of manually cutting the rim at a very low cost, thereby improving the yield rate and production efficiency of cold-rolled products. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a schematic flow chart of a method for manufacturing a cold-rolled product provided in one embodiment of the present application;

[0022] Figure 2 is a schematic flow chart of a method for manufacturing a cold-rolled product provided in another embodiment of the present application;

[0023] Figure 3 It is a schematic flow chart of a method for manufacturing cold-rolled products provided in another embodiment of the present application. DETAILED DESCRIPTION

[0024] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0025] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

[0027] In the process of steel smelting, the raw materials for steelmaking are first smelted into slab materials. After that, the slab materials are subjected to rough rolling and finish rolling to obtain hot-rolled coils that meet product standards in terms of thickness, width, surface quality and plate shape. The hot-rolled coils are transported to the cold rolling unit, where the oxidized iron scale on the surface of the hot-rolled coils is removed by pickling and cold rolling, so that the thicker hot-rolled coils are rolled into thinner chilled coils. The chilled coils also need to be annealed to eliminate the work hardening of the chilled coils caused by cold rolling.

[0028] Hood furnace annealing is a common annealing method used in domestic cold-rolled sheet mills. The main process of an existing hood furnace annealing is to flip the vertical chilled coil into a horizontal state through a steel turning machine, and then use a vertical clamp to put the horizontal chilled coil into the hood furnace. The chilled coils in the hood furnace are separated by the convection plate in the furnace for annealing.

[0029] However, during the bell-type furnace annealing process, the inner and outer rings of the chilled coil often adhere together due to the extrusion of the bell-type furnace convection plate, resulting in hemming at the edges of the chilled coil, especially at the head and tail of the chilled coil. Hemming will affect the quality of the final finished steel coil, so it is necessary to manually cut off the hemming part before the next step of annealing. Manually cutting off the hemming not only increases the labor cost of production, affects the production efficiency of steel coil production, but also reduces the utilization rate of raw materials of the steel coil.

[0030] After discovering that the chilled coil will produce hemming during the hood furnace annealing process, the inventor of the present application further discovered that the cause of hemming is that the head and tail of the chilled coil are too wide. Therefore, in order to solve the above technical problems, the present application creatively proposes that in the rough rolling process during the steel coil production process, the width of the intermediate billet is adjusted by adjusting the parameters of the rough rolling, and the width of the head and tail of the intermediate billet is controlled to be appropriately narrowed. Since the chilled coil will inherit the width of the intermediate billet, the width of the head and tail of the chilled coil will also be narrowed. In this way, the problem of hemming caused by the extrusion of the convection plate in the hood furnace when the chilled coil is annealed in a hood furnace can be solved.

[0031] Specifically, in order to solve the problems of the prior art, the embodiment of the present application provides a high-efficiency cold-rolled product manufacturing method. The cold-rolled product manufacturing method provided by the embodiment of the present application is introduced below.

[0032] Figure 1 A schematic flow chart of a cold-rolled product manufacturing method provided by an embodiment of the present application is shown. The method comprises the following steps:

[0033] S110, rough rolling is performed on the provided slab according to the first head and tail short stroke value. During the rough rolling process, according to the first head and tail short stroke value of the rough rolling vertical roller, the rough rolling vertical roller is controlled to squeeze the head and tail of the slab more than the middle section of the slab, so as to obtain an intermediate slab that meets a preset size specification; the preset size specification is that the width of the head and tail of the intermediate slab is smaller than the width of the middle section.

[0034] In this embodiment, the slab is rough-rolled by a rough-rolling machine, which includes at least two rough-rolling vertical rollers, which are respectively installed on both sides of the strip. When the slab passes through the roll gap between the two rough-rolling vertical rollers, the rough-rolling vertical rollers squeeze the slab, thereby controlling the width of the slab. Therefore, the width of the slab is determined by the position of the rough-rolling vertical rollers and the width of the roll gap.

[0035] The position of the roughing vertical roller and the width of the roll gap are determined by a preset reference value and a head and tail short stroke value. The preset reference value is the position of the roughing vertical roller and the width of the roll gap defined by default by the secondary control (L2) system of the roughing machine, while the head and tail short stroke value is set by the user and is used to adjust the width of the roll gap and compensate for the width of the head and tail of the slab, that is, to make the width of the roll gap narrower or wider based on the reference value. The first head and tail short stroke value is an embodiment of the head and tail short stroke value in the present application.

[0036] In this embodiment, during the rough rolling of the slab, when different positions of the slab are squeezed by the rough rolling vertical rollers, the roll gap of the rough rolling vertical rollers changes with the change of the position of the slab. Due to the existence of the first head and tail short stroke value, when the head and tail of the slab are squeezed, the roll gap of the two rough rolling vertical rollers is narrower than the roll gap when the middle section of the slab is squeezed, so the squeezing degree of the head and tail of the slab by the rough rolling vertical rollers is greater than the squeezing degree of the middle section of the slab, so that the intermediate billet made of the slab meets the preset size specifications, that is, the width of the head and tail is smaller than the width of the middle section.

[0037] S120, the intermediate billet is finish-rolled to obtain a hot-rolled coil, and the hot-rolled coil is sequentially pickled and cold-rolled, annealed in a bell furnace, leveled by a leveler, and leveled and divided into coils or cut into plates to obtain a cold-rolled product.

[0038] In this embodiment, after the slab is rough-rolled to obtain an intermediate slab that meets the preset size specifications, the intermediate slab can also be finish-rolled to obtain a hot-rolled coil, and the hot-rolled coil can be subjected to operations such as pickling and cold rolling, hood furnace annealing, leveling by a leveler, finishing and coiling or cutting to finally obtain a cold-rolled product. The cold-rolled product can be a cold-rolled steel plate or a cold-rolled steel coil.

[0039] Taking the cold-rolled product as cold-rolled steel coil as an example, finishing rolling can further roll the relatively thick intermediate billet into a relatively thin hot-rolled coil, and each position of the hot-rolled coil inherits the width of the corresponding position of the intermediate billet. Then, the hot-rolled coil can be pickled and cold-rolled. Pickling and cold-rolling can remove the iron oxide scale on the surface of the hot-rolled coil and turn the hot-rolled coil into a thinner chilled coil. Pickling and cold-rolling can also inherit the width of each position of the hot-rolled coil. Then the chilled coil is placed in a bell-type furnace for annealing to obtain a bell-type annealed coil.

[0040] By further eliminating the yield platform of the hood unwinding through the flattening process and re-splitting the flattened coil in the finishing and splitting process, a cold-rolled steel coil that meets the requirements can be obtained.

[0041] The present application only optimizes the head and tail short stroke values ​​to control the width of the head and tail of the intermediate billet to be smaller than the width of the middle section during the rough rolling process. Therefore, on the chilled coil that inherits the width of the intermediate billet, the width of the head and tail is also smaller than the width of the middle section. As a result, during the annealing of the chilled coil in the hood furnace, the convection plate in the furnace will not squeeze the chilled coil and cause it to fold over the edge. This avoids the process of manually cutting off the fold at a very low cost, thereby improving the yield rate and production efficiency of cold-rolled products.

[0042] As an optional embodiment, the range of the first head-tail short stroke value is -11 to 8 mm.

[0043] In this embodiment, the first head and tail short stroke value refers to the value increased by adjusting the rough rolling vertical roll to control the roll gap based on the system default defined reference value, and is also the value increased by the width of the intermediate billet based on the default defined set value.

[0044] That is, if the first head and tail short stroke value is 8 mm, it means that the width of the intermediate billet is 8 mm wider than the set value; if the first head and tail short stroke value is -11 mm, it means that the width of the intermediate billet is 11 mm narrower than the set value.

[0045] As an alternative embodiment, please refer to Figure 3 In order to prevent each type of steel coil from having hemming, before S110, the following steps may also be included:

[0046] S310, for a plurality of target positions at the head and tail of the slab, when the plurality of target positions are in different thickness ranges, setting a first head and tail short stroke value of the roughing vertical roll.

[0047] In this embodiment, for multiple target positions at the head and tail of the slab, a group of first head and tail short stroke values ​​of the rough rolling vertical rollers are set at each target position, and each group of head and tail short stroke values ​​can represent the first head and tail short stroke values ​​corresponding to the thickness range when a target position is in different thickness ranges.

[0048] Due to the different thickness of the slab, the thickness of the chilled coils made from it will be different, and the probability of the chilled coils with different thicknesses producing hemming during the bell-type furnace annealing process is also different. Therefore, even if it is the same target position on the slab, the different thickness ranges will lead to different set first head and tail short stroke values.

[0049] By setting different first head and tail short stroke values ​​in different thickness intervals at multiple target positions, it is possible to avoid edge wrapping of steel coils of each thickness, thereby improving the efficiency of steel coil production without affecting the production quality of the steel coils.

[0050] As an optional embodiment, the first head-tail short stroke value includes a first head short stroke value. When the target position is on a first side, the range of the first head short stroke value is -5 to 3 mm, and the first side is a side of the head of the slab away from the tail.

[0051] When the distance between the target position and the first side is a preset distance, the short stroke value of the first head is in the range of 2 to 8 mm.

[0052] In this embodiment, the first head-tail short stroke value includes the first head short stroke value, which can be used to adjust the position of the roughing vertical roll and the width of the roll gap based on the reference value when the head of the slab passes through the roll gap. That is, the first head short stroke value is the value added to the control roll gap based on the reference value defined by the system by default when the head of the slab passes through the roll gap.

[0053] The head of the slab includes multiple target positions, and different target positions correspond to different first head short stroke values; even at the same target position, when the target position is in different thickness ranges, the first head short stroke value is also different. In one embodiment, the thicker the same target position is, the larger the first head short stroke value is.

[0054] For example, when the target position is on the first side, the range of the first head short stroke value is -5 to 3 mm. Furthermore, when the thickness of the target position on the first side is less than 70 mm, the first head short stroke value is -5 mm. When the thickness of the target position on the first side is greater than 70 mm and less than or equal to 110 mm, the first head short stroke value is -3 mm. When the thickness of the target position on the first side is greater than 110 mm and less than or equal to 210 mm, the first head short stroke value is 0. When the thickness of the target position on the first side is greater than 210 mm, the first head short stroke value is 3 mm. When the distance between the target position and the first side is a preset distance, the range of the first head short stroke value is 2 to 8 mm. The preset distance can be 0.3 meters. The specific first head short stroke values ​​are shown in Table 1 below.

[0055] Table 1

[0056]

[0057]

[0058] As an optional embodiment, the first head-tail short stroke value includes a first tail short stroke value, and when the target position is on the second side, the tail short stroke value ranges from -11 to -5 mm, and the second side is the side of the tail of the slab away from the head;

[0059] When the distance between the target position and the first side is a preset distance, the range of the first tail short stroke value is -4 to 0 mm.

[0060] In this embodiment, the first head and tail short stroke value includes the first tail short stroke value, which can be used to adjust the position of the roughing vertical roll and the width of the roll gap based on the reference value when the tail of the slab passes through the roll gap. That is, the first tail short stroke value is the value added to the control roll gap based on the reference value defined by the system by default when the tail of the slab passes through the roll gap.

[0061] The tail of the slab includes multiple target positions, and different target positions correspond to different first tail short stroke values; even at the same target position, the first tail short stroke value is different when the target position is in different thickness ranges. In one embodiment, the thicker the same target position is, the larger the first tail short stroke value is.

[0062] For example, when the target position is on the second side, the range of the first tail short stroke value is -11 to -5 mm. Furthermore, when the thickness of the target position on the second side is less than 70 mm, the first tail short stroke value is -11 mm. When the thickness of the target position on the second side is greater than 70 mm and less than or equal to 110 mm, the first tail short stroke value is -6 mm. When the thickness of the target position on the second side is greater than 110 mm and less than or equal to 210 mm, the first tail short stroke value is -6 mm. When the thickness of the target position on the second side is greater than 210 mm, the first tail short stroke value is -5 mm. When the distance between the target position and the second side is a preset distance, the range of the first tail short stroke value is -4 to 0 mm. The preset distance can be 0.3 meters. The specific first tail short stroke values ​​are shown in Table 2 below.

[0063] Table 2

[0064]

[0065] As an alternative embodiment, please refer to Figure 3In order to determine the production process and production parameters of the slab, before S110, the following steps may also be included:

[0066] Adjusting the original grade of the slab to the grade of the slab;

[0067] Determine whether to perform rough rolling on the provided slab according to the first head and tail short stroke values ​​based on the slab brand.

[0068] In this embodiment, each slab has a corresponding grade, which can be used to characterize the identity information of the slab and the process production flow that needs to be carried out next. The original grade of the slab is the grade of the slab preset by the machine, and the user can adjust the original grade of the slab to the slab grade according to the specific composition of the slab and the needs of the user, thereby changing the production process and process parameters required for the slab. For example, the rough rolling vertical roller can read whether to perform rough rolling on the slab according to the adjustment of the slab grade according to the first head and tail short stroke value.

[0069] In one embodiment, the slab can be produced into a hot-rolled commodity coil, a hood-annealed hot-rolled base plate, and a galvanized hot-rolled base plate; among them, since only the hood-annealed hot-rolled base plate needs to be annealed in a hood-annealed furnace, there is a risk of forming an edge wrap, so during the rough rolling process, the hood-annealed hot-rolled base plate corresponds to a first head-to-tail short stroke value, and the hot-rolled commodity coil and the galvanized hot-rolled base plate correspond to a second head-to-tail short stroke value. In the case of the same target position and the same thickness range of the target position, the second head-to-tail short stroke value is greater than or equal to the first head-to-tail short stroke value.

[0070] For example, the original grade of the slab shows that the slab is produced as a hot-rolled commodity coil, and the user finds that the composition of the slab is more suitable for making a hood-annealed hot-rolled base plate, so the user will adjust the original grade of the slab to the slab grade, and the adjusted slab grade indicates that the production direction of the slab is a hood-annealed hot-rolled base plate. The rough rolling machine will read the first head and tail short stroke value based on the adjusted slab grade, and rough roll the slab based on the first head and tail short stroke value.

[0071] In this way, by adjusting the brand number, it is possible to quickly and easily ensure that the most suitable production process and production parameters are assigned to each slab, avoiding the occurrence of production risks such as hemming.

[0072] The above is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A method for manufacturing a cold-rolled product, characterized in that: The method comprises: In the case where the process flow of the slab includes bell-type furnace annealing in a target mode, the provided slab is rough rolled according to the first head and tail short stroke value. During the rough rolling process, according to the first head and tail short stroke value of the rough rolling vertical roller, the rough rolling vertical roller is controlled to squeeze the head and tail of the slab more than the middle section of the slab, so as to obtain an intermediate slab meeting a preset size specification; the preset size specification is that the width of the head and tail of the intermediate slab is less than the width of the middle section; The intermediate billet is sequentially subjected to finish rolling, pickling and cold continuous rolling, bell-type furnace annealing in the target mode, leveling by a leveler, and finishing and coiling or plate cutting to obtain a cold-rolled product; The target method of bell-type furnace annealing includes: placing the intermediate billets after pickling and cold rolling in a horizontal state into the bell-type furnace, and placing the intermediate billets at intervals through the convection plates in the bell-type furnace for annealing.

2. The method for manufacturing cold rolled products according to claim 1, characterized in that: The first head-to-tail short stroke value ranges from -11 to 8 mm.

3. The method for manufacturing cold rolled products according to claim 1, characterized in that: Before rough rolling the provided slab according to the first head and tail short stroke value, the method further includes: With respect to a plurality of target positions of the head and tail of the slab, when the plurality of target positions are in different thickness ranges, a first head and tail short stroke value of the roughing vertical roll is set.

4. The method for manufacturing cold rolled products according to claim 3, characterized in that: The first head-tail short stroke value includes a first head short stroke value. When the target position is on a first side, the first head short stroke value ranges from -5 to 3 mm. The first side is a side of the head of the slab away from the tail. When the distance between the target position and the first side is a preset distance, the short stroke value of the first head is in the range of 2 to 8 mm.

5. The method for manufacturing cold rolled products according to claim 3, characterized in that: The first head-tail short stroke value includes a first tail short stroke value, and when the target position is on the second side, the tail short stroke value ranges from -11 to -5 mm, and the second side is the side of the tail of the slab away from the head; When the distance between the target position and the first side is a preset distance, the range of the first tail short stroke value is -4 to 0 mm.

6. The method for manufacturing cold rolled products according to claim 1, characterized in that: Before rough rolling the provided slab according to the first head and tail short stroke value, the method further includes: Adjusting the original grade of the slab to the grade of the slab; Determine whether to perform rough rolling on the provided slab according to the first head and tail short stroke values ​​based on the slab brand.

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