High-precision special steel bar reducing system

Abstract

The utility model belongs to the field of bar rolling technology relates to a kind of high-precision special steel bar reducing sizing production system, including two two-high rolling mill, two three-high rolling mill, water tank after reducing sizing and finished product collection system being sequentially arranged along the rolling direction.The utility model is innovatively configured with the combination of 2 two-high rolling mill of low cost and 2 high-precision three-high rolling mill, and an efficient reducing sizing production system is constructed.Compared with traditional three-high rolling mill system, this design significantly reduces the number of expensive three-high rolling mill, thereby reducing equipment purchase and maintenance costs.At the same time, two high rolling mill leads the primary rolling of large-scale bar, effectively reducing energy consumption and production cost.This configuration ensures product precision while significantly optimizing cost structure, especially suitable for production scenarios with high economic requirements.

Description

Technical Field

[0001] This utility model belongs to the field of bar rolling technology and relates to a high-precision special steel bar sizing and reduction production system, which is applicable to the production of various steel products such as round steel, flat steel, and rebar, and is especially suitable for the production of special steel bars with high requirements for dimensional accuracy, surface quality and mechanical properties. Background Technology

[0002] In the production of special steel bars, reduction sizing technology is a core component in ensuring product dimensional accuracy, surface quality, and mechanical properties. Traditional reduction sizing processes primarily utilize three-roll mills. While these mills can guarantee relatively high dimensional accuracy to a certain extent, the technology faces numerous unresolved issues.

[0003] First, high equipment investment costs are a major drawback of traditional reduction sizing processes. The manufacturing and maintenance costs of 4-5 three-roll mills are both high, resulting in a persistently high overall investment cost for the production line and placing a heavy financial burden on enterprises. Insufficient production flexibility also restricts the development of traditional reduction sizing processes. In actual production, the demand for bars of different specifications and shapes (such as round steel, flat steel, ribbed steel bars, hexagonal steel, square steel, etc.) varies, and existing technologies struggle to flexibly switch between producing different specifications and shapes on the same production line. Producing bars of different specifications often requires frequent changes to the die system, a time-consuming and labor-intensive process that leads to low production efficiency and makes it difficult for enterprises to quickly respond to changes in market demand. Traditional technologies also face a dilemma in balancing dimensional accuracy and cost. High-precision production typically relies on three-roll mills, but their production costs are high; while two-roll mills, although lower in cost, are insufficient to meet high-precision requirements. Furthermore, existing technologies lack precise control over rolling temperature and cooling rate, leading to unstable mechanical properties and surface quality of the products, affecting product quality.

[0004] In summary, current market-standard reduction sizing technologies suffer from several drawbacks, including high equipment investment costs, insufficient production flexibility, difficulty in balancing dimensional accuracy and cost, and inadequate application of controlled rolling and cooling technologies. The inability to flexibly switch between producing bars of different specifications and shapes on the same production line leads to low production efficiency and difficulty in responding to market demands. Regarding dimensional accuracy and cost control, high-precision production often relies on three-roll mills, resulting in higher production costs. While two-roll mills are less expensive, they are insufficient to meet high-precision requirements, making it difficult for companies to find a balance between dimensional accuracy and cost. Furthermore, the insufficient application of controlled rolling and cooling technologies is a significant problem, leading to unstable mechanical properties and surface quality of the products, thus affecting overall product quality. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a high-precision special steel bar sizing and reduction production system to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A high-precision special steel bar sizing and reduction production system includes a two-stand two-roll mill, a two-stand three-roll mill, a sizing and reduction water tank, and a finished product collection system arranged sequentially along the rolling direction.

[0008] Furthermore, the finished product collection system includes any of the following configurations:

[0009] Multiple-length flying shear, braking skirt and cooling bed are arranged sequentially along the rolling direction;

[0010] Or double-length flying shears, tail brakes, rotating hubs, and cooling beds;

[0011] Or a winding machine.

[0012] Furthermore, both the two-stand two-roll mill and the two-stand three-roll mill are equipped with inter-stand loopers.

[0013] Furthermore, a rolling mill looper is provided between the two-stand two-roll rolling mill and the two-stand three-roll rolling mill.

[0014] Furthermore, in the two-stand two-roll mill, the first stand has a pass shape of one of box pass, elliptical pass, round pass, and rhombic square pass, and the second stand has a pass shape of one of box pass, round pass, ribbed round pass, and square pass;

[0015] Furthermore, in the two-stand three-roll mill, the first stand has a die type of one of round die type, arc-triangular die type, ribbed round die type, and hexagonal die type, and the second stand has a die type of one of round die type and hexagonal die type.

[0016] Furthermore, there are 1 to 5 water tanks after the sizing and reducing process, and each water tank after the sizing and reducing process is equipped with a recovery section.

[0017] Furthermore, the rolls in the two-stand three-roll mill are designed with a 120° symmetrical arrangement.

[0018] The beneficial effects of this utility model are as follows:

[0019] 1. Significantly reduce equipment investment and production costs

[0020] This invention innovatively combines two low-cost two-roll mills with two high-precision three-roll mills to create a highly efficient sizing production system. Compared to traditional all-three-roll mill systems, this design significantly reduces the number of expensive three-roll mills required, thereby lowering equipment purchase and maintenance costs. Simultaneously, the two-roll mills dominate the initial rolling of large-diameter bars, effectively reducing energy consumption and production costs. This configuration significantly optimizes the cost structure while ensuring product precision, making it particularly suitable for production scenarios with high economic requirements.

[0021] 2. Achieve high precision and high quality products

[0022] This invention utilizes a symmetrical roll pass design, low-width spread technology, and precise tension control in a three-roll sizing mill to achieve high-precision rolling of workpieces, with dimensional tolerances exceeding ±0.05mm. Furthermore, the multi-stage water tank segmented cooling technology at the system's rear end effectively prevents the formation of red rust on the workpiece surface by dynamically adjusting rolling temperature, speed, and cooling rate, further improving the product's surface quality, dimensional accuracy, and mechanical properties. This innovative process meets the stringent requirements of high-end special steel bars in the high-end market, providing a reliable guarantee for high-quality production.

[0023] 3. Enhance production diversity and efficiency

[0024] This tapering production system supports diverse roll pass configurations, such as elliptical-round-round-round combinations, enabling flexible production of various specifications of round steel, flat steel, and ribbed steel bars to meet the needs of different industries, including construction and machinery. The system features rapid switching between rolling modes, eliminating the need for frequent roll pass changes, significantly reducing production preparation time and improving overall efficiency. This practical design not only achieves efficient collaborative production of multiple varieties and specifications but also enhances the company's ability to quickly respond to market changes.

[0025] 4. Enhance economic benefits and social value

[0026] This technical solution significantly enhances product market competitiveness through a low-cost, high-precision production model, making it widely applicable to traditional industries such as automotive, general machinery, and construction, while also meeting the needs of high-end sectors like aerospace, rail transportation, and advanced equipment manufacturing. Furthermore, by optimizing energy utilization and reducing material waste, the system embodies the concept of green manufacturing, aligning with the trend of sustainable development. This innovative solution not only brings significant economic benefits to enterprises but also provides crucial support for the transformation, upgrading, and high-quality development of the steel industry.

[0027] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0029] Figure 1 This is a schematic diagram of the layout of a high-precision special steel bar sizing and reduction production system in an embodiment.

[0030] Figure 2 This is a production flow diagram of a high-precision special steel bar sizing and reduction production system in an embodiment.

[0031] Figure 3 This is an elliptical pass diagram of the two-stand two-roll mill in the embodiment;

[0032] Figure 4 This is a diagram of the circular hole profile of the two-stand two-roll mill in the embodiment;

[0033] Figure 5 This is a diagram of the arc-triangular pass profile of the two-stand three-roll mill in the embodiment;

[0034] Figure 6 This is a diagram of the circular hole profile of the three-roll mill in the second stand of the embodiment.

[0035] Attached reference numerals: 1. Two-stand two-roll mill; 2. Two-stand three-roll mill; 3. Water tank after sizing; 4. Multiple length flying shear; 5. Cooling bed; 6. Coiler. Detailed Implementation

[0036] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0037] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0038] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0039] Please see Figures 1-6 This is a high-precision special steel bar sizing and reduction production system, which includes a two-stand two-roll mill 1, a two-stand three-roll mill 2, a sizing and reduction water tank 3, and a finished product collection system arranged sequentially along the rolling direction.

[0040] Furthermore, the finished product collection system includes any of the following configurations:

[0041] The multiple-length flying shear 4, the braking skirt (a conventional device, not shown in the figure) and the cooling bed 5 are arranged sequentially along the rolling direction;

[0042] Or double-length flying shear 4, tail brake (conventional device, not shown in the figure), rotating hub (conventional device, not shown in the figure) and cooling bed;

[0043] Or a winding machine 6.

[0044] Furthermore, both the two-stand two-roll mill 1 and the two-stand three-roll mill 2 are equipped with inter-stand loopers (conventional devices, not shown in the figure); an inter-mill looper (conventional device, not shown in the figure) is provided between the two-stand two-roll mill 1 and the two-stand three-roll mill 2.

[0045] Specifically, both the inter-stand looper and the inter-mill looper are equipped with a looper dynamic system, which includes:

[0046] Speed ​​difference response module: Real-time monitoring of speed differences between adjacent racks and triggering looper action;

[0047] Height maintenance mechanism: A closed-loop control system is used to maintain a stable working height of the looper roller;

[0048] Safety protection unit: Includes a dual protection mechanism of electronic emergency stop device and mechanical limit switch;

[0049] Mode adaptation device: Automatically adjusts looper operating parameters based on rolling schedule.

[0050] Please see Figures 3-6 Furthermore, in the two-stand two-roll mill, the first stand has a hole type of box hole, elliptical hole, round hole, or rhombic square hole, and the second stand has a hole type of box hole, round hole, ribbed round hole, or square hole.

[0051] The first stand of the two-stand three-roll mill has a pass type of one of the following: round pass, arc-triangular pass, ribbed round pass, and hexagonal pass. The second stand has a pass type of one of the following: round pass and hexagonal pass.

[0052] Specifically, this high-precision special steel bar sizing and reduction production system can flexibly switch between two-stand, three-stand, and four-stand rolling modes. By configuring different pass systems, it can meet the production needs of round steel, flat steel, ribbed steel bars, hexagonal steel, and square steel. The rolling stands selected for different products are as follows:

[0053] 1) For round steel products, depending on the dimensional accuracy requirements and rolling specifications, two-stand two-roll mills, three-stand (two-stand two-roll mill + one of the three-roll mills in the two-stand three-roll mills) or four-stand rolling (two-stand two-roll mill + two-stand three-roll mill) can be flexibly adopted.

[0054] 2) For flat steel products, a two-stand, two-roll mill is used for rolling;

[0055] 3) For ribbed steel bar products, two-ribbed steel bars are rolled using a two-stand two-roll mill, and three-ribbed steel bars are rolled using a three-stand mill (two-stand two-roll mill + one three-roll mill from the two-stand three-roll mill).

[0056] 4) The rolling method for hexagonal steel products is similar to that for round steel products;

[0057] 5) For square steel products, a two-stand, two-roll mill is used for rolling.

[0058] Furthermore, the hole profile systems for producing different products are configured as follows:

[0059] 1) The hole pattern system for the flat steel is box-to-box;

[0060] 2) The two-stand die pattern system for round steel is ellipse-circle, the three-stand die pattern system for round steel is ellipse-circle-circle, and the four-stand die pattern system for round steel is ellipse-circle-arc triangle-circle;

[0061] 3) The hole pattern system for two-ribbed structural steel is elliptical-ribbed circle, and the hole pattern system for three-ribbed structural steel is elliptical-circle-ribbed circle.

[0062] 4) The two-frame hole pattern system of hexagonal steel is round-hexagonal, the two-frame hole pattern system of hexagonal steel is elliptical-round-hexagonal, and the two-frame hole pattern system of hexagonal steel is elliptical-round-arc triangle-hexagonal;

[0063] 5) The hole pattern system of square steel is rhombus-square or box-square.

[0064] The specifications for round steel rolling range from φ12mm to φ300mm, and the specifications for construction steel rolling range from φ10mm to φ50mm, with a maximum rolling speed of ≤50m / s. The rolling temperature of each stand of the two-stand two-high rolling mill is 750℃ to 1100℃, and the elongation coefficient of each stand is 1.05 to 1.45. The rolling temperature of each stand of the two-stand three-high rolling mill is 700℃ to 1050℃, with the elongation coefficient of the first three-high rolling mill being 1.05 to 1.30 and the elongation coefficient of the second three-high rolling mill being 1.01 to 1.15. The dimensional tolerance of the products rolled by the reduction sizing production system is ±0.05mm or more.

[0065] Furthermore, there are 1 to 5 water tanks after the sizing and reducing process, and each water tank after the sizing and reducing process is equipped with a recovery section.

[0066] Furthermore, the rolls in the two-stand three-roll mill are designed with a 120° symmetrical arrangement.

[0067] Example 1: Production of φ50mm round steel

[0068] 1. System Structure and Configuration

[0069] like Figure 1 As shown, the high-precision special steel bar sizing and reduction production system used in this embodiment includes a two-stand two-high rolling mill 1, a two-stand three-high rolling mill 2, a water tank 3 after sizing and reduction, and a finished product collection system arranged sequentially along the rolling direction. The specific configuration is as follows:

[0070] Two-stand two-high rolling mill 1: Consists of two two-stand rolling mills, the first stand adopts an elliptical pass type (e.g., ...). Figure 3 As shown), the second frame adopts a round hole type (such as...). Figure 4 (As shown). An interstand loop is provided between the two stands to adjust the tension of the rolled piece.

[0071] Two-stand three-roll mill 2: Consists of two three-roll mills, with the first stand using an arc-triangular pass type (e.g., ...). Figure 5 As shown), the second frame adopts a round hole type (such as...). Figure 6 (As shown). The rolls of each mill are arranged symmetrically at 120° to ensure the uniformity of the rolled piece cross-section and dimensional accuracy. A lobe is also provided between the two stands.

[0072] Inter-mill looper: An inter-mill looper is provided between the two-stand two-roll mill 1 and the two-stand three-roll mill 2 to ensure a smooth transition of the rolled workpiece.

[0073] Water tank 3 after sizing: It is equipped with two water tanks, each with a recovery section to control the cooling rate and the temperature of the rolled piece.

[0074] Finished product collection system: It adopts a double-length flying shear 4, a braking skirt and a cooling bed 5 arranged in sequence along the rolling direction, which is suitable for shearing and cooling of straight bars.

[0075] 2. Production process

[0076] like Figure 2 As shown, the specific process for producing φ50mm round steel is as follows:

[0077] Step 1: Preparation of finished rolled parts

[0078] After being rolled by the upstream finishing rolling system, the cross-sectional area of ​​the bar is approximately 3848 mm². 2 The running speed is 2.39 m / s. After finishing rolling, the workpiece is cooled in a water tank, and the temperature drops to 760℃~780℃. It is then conveyed to the two-stand two-high rolling mill 1 by the roller conveyor.

[0079] Step 2: Two-stand two-roll rolling

[0080] The workpiece enters a two-stand, two-high rolling mill 1. The first stand (elliptical pass type) rolls the workpiece into an elliptical cross-section, and the second stand (circular pass type) further shapes it into an approximately circular cross-section. Guide devices are installed before and after each stand. During rolling, the deformation compression ratio for each pass is controlled at 1.291, and the deformation temperature is 780℃~880℃. After rolling, the equivalent diameter of the workpiece is approximately 54.2mm, and the running speed is increased to 3.985m / s.

[0081] Step 3: Two-stand three-roll rolling

[0082] The rolled piece enters the two-stand three-high rolling mill 2 via the inter-mill looper. The first stand (arc-triangular pass) performs preliminary sizing, and the second stand (circular pass) completes the final sizing. Each stand is equipped with guide devices at both ends. The deformation compression ratio for each pass is controlled at 1.07, and the deformation temperature is 800℃~900℃. After rolling, the equivalent diameter of the rolled piece is 50.05mm, the finished product dimensional tolerance is ±0.05mm or higher, and the running speed is 4.56m / s.

[0083] Step 4: Cooling and Collection

[0084] After rolling, the bar stock enters the sizing tank 3. Through the configuration of two tanks and a recovery section, the cooling rate is precisely controlled at 5℃ / s to 10℃ / s to prevent surface red rust. After cooling, the bar stock is sheared into multiple lengths by the long-length flying shear 4 and sent to the cooling bed 5 for further cooling. The temperature of the upper cooling bed is 750℃ to 800℃.

[0085] 3. Technical Effects

[0086] This embodiment utilizes the coordinated operation of a two-stand two-roll mill and a three-roll mill to produce φ50mm round steel with a dimensional tolerance of ±0.05mm, high surface finish, and stable mechanical properties. The system configuration is flexible, the equipment occupies a small area, and it is suitable for mass production of round steel.

[0087] Example 2: Production of φ20mm ribbed steel bars

[0088] 1. System Structure and Configuration

[0089] This embodiment uses the same high-precision special steel bar sizing and reduction production system as Embodiment 1, but adjusts some of the hole patterns and finished product collection system to meet the production needs of ribbed steel bars. The specific configuration is as follows:

[0090] Two-stand two-roll mill 1: The first stand has an elliptical end cap, and the second stand has a circular end cap, used for preliminary sizing. An interstand looper is provided between the two stands.

[0091] Two-stand three-roll mill 2: The first stand adopts a ribbed round hole type for final sizing and rib forming, and the second stand (does not participate in rolling, passes through empty). The rolls adopt a 120° symmetrical arrangement design, and there is an inter-stand looper between the two stands.

[0092] Inter-mill looper: installed between two-stand two-high mill 1 and two-stand three-high mill 2 to ensure the continuity of rolled products.

[0093] Water tank 3 after sizing: It is equipped with 3 water tanks, each with a recovery section to meet the cooling requirements of the ribbed steel bars.

[0094] Finished product collection system: The system uses a coiler 6, which is suitable for collecting coiled bar stock.

[0095] 2. Production process

[0096] The specific process for producing φ20mm ribbed steel bars is as follows:

[0097] Step 1: Preparation of finished rolled parts

[0098] After being rolled by the finishing rolling system, the cross-sectional area of ​​the bar is approximately 415 mm². 2 The running speed is 10m / s. After finishing rolling, the water tank is cooled to 800℃~820℃ before being sent to the two-stand two-roll mill 1.

[0099] Step 2: Two-stand two-roll rolling

[0100] The workpiece enters a two-stand, two-high rolling mill 1. The first stand (elliptical pass type) rolls the workpiece into an elliptical cross-section, and the second stand (circular pass type) performs preliminary sizing. The deformation compression ratio is controlled at 1.15, and the deformation temperature is 820℃~900℃. After rolling, the equivalent diameter of the workpiece is approximately 22.5mm, and the running speed is 12.5m / s.

[0101] Step 3: Two-stand three-roll rolling

[0102] The rolled piece enters the two-stand three-high rolling mill 2 via the inter-mill looper. The first stand (ribbed round hole) performs final sizing and rib formation standardization on the rolled piece, while the second stand passes through without load. The deformation compression ratio is controlled at 1.05, and the deformation temperature is 850℃~920℃. After rolling, the equivalent diameter of the rolled piece is 20.02mm, and the running speed is 14m / s.

[0103] Step 4: Cooling and Collection

[0104] After rolling, the ribbed steel bars enter the sizing tank 3. Through the configuration of three tanks and a recovery section, the cooling rate is controlled at 8℃ / s to 12℃ / s to ensure the quality of the ribs and mechanical properties. After cooling, the ribbed steel bars are sent to the coiler 6 for coiling and collection.

[0105] 3. Technical Effects

[0106] This embodiment, by adjusting the hole pattern system and collection method, produces φ20mm ribbed steel bars with a dimensional tolerance of ±0.05mm, uniform rib pattern, and compliance with building steel standards. The system is flexible and can quickly adapt to the production of ribbed steel bars of different specifications.

[0107] The two embodiments above demonstrate the specific applications of the high-precision special steel bar sizing and reduction production system in the production of φ50mm round steel and φ20mm ribbed steel bars. By flexibly configuring the die system, mill looper, and finished product collection system, this system can efficiently produce high-precision bars of various specifications, demonstrating its technological advantages and wide applicability.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A high-precision special steel bar sizing and reduction production system, characterized in that, It includes a two-stand two-roll mill, a two-stand three-roll mill, a water tank after sizing and reducing, and a finished product collection system arranged sequentially along the rolling direction; The two-stand two-roll mill and the two-stand three-roll mill are equipped with inter-stand loopers; an inter-mill looper is provided between the two-stand two-roll mill and the two-stand three-roll mill.

2. The high-precision special steel bar sizing and reduction production system according to claim 1, characterized in that, The finished product collection system includes any of the following configurations: Multiple-length flying shear, braking skirt and cooling bed are arranged sequentially along the rolling direction; Or double-length flying shears, tail brakes, rotating hubs, and cooling beds; Or a winding machine.

3. The high-precision special steel bar sizing and reduction production system according to claim 1, characterized in that, The first stand of the two-stand two-roll mill has a pass type of one of box pass, elliptical pass, round pass, or rhomboid pass, and the second stand has a pass type of one of one of box pass, round pass, ribbed round pass, or square pass.

4. The high-precision special steel bar sizing and reduction production system according to claim 3, characterized in that, The first stand of the two-stand three-roll mill has a pass type of one of the following: round pass, arc-triangular pass, ribbed round pass, and hexagonal pass. The second stand has a pass type of one of the following: round pass and hexagonal pass.

5. The high-precision special steel bar sizing and reduction production system according to claim 1, characterized in that, There are 1-5 water tanks after the sizing and reducing process, and each water tank after the sizing and reducing process is equipped with a recovery section.

6. The high-precision special steel bar sizing and reduction production system according to claim 1, characterized in that, The rolls in the two-stand three-roll mill are arranged symmetrically at 120°.

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