Method for controlling horizontal continuous casting of copper clad steel and horizontal continuous casting system for producing copper clad steel

Abstract

The present disclosure discloses a copper-coated steel horizontal continuous casting control method and a horizontal continuous casting system for producing copper-coated steel, the method comprising: horizontally maintaining the copper liquid contained in the inner cavity at a first predetermined height higher than the steel wire in the continuous casting furnace; controlling the running of the steel wire, feeding through the inner cavity of the melting furnace, and discharging after entering the casting cavity of the crystallizer, wherein the total residence time of the steel wire in the furnace from feeding to discharging is controlled to heat the steel wire to a first set temperature when entering the casting cavity of the crystallizer; and making the copper liquid in the inner cavity enter the casting cavity through the pouring hole of the crystallizer, so that the copper liquid crystallizes on the surface of the steel wire to form a copper-coated steel wire. The solution provided by the present disclosure is beneficial to the combination of copper liquid and steel wire surface, improves the coating effect of copper layer on the surface of steel wire, and improves the continuous casting quality of copper-coated steel wire.

Description

Technical Field

[0001] This disclosure relates to the field of metal continuous casting composite technology, and in particular to a horizontal continuous casting control method for copper-clad steel, a horizontal continuous casting system for producing copper-clad steel, and copper-clad steel wire produced therefrom. Background Technology

[0002] In the production of various steel products, there are two methods for solidifying liquid metal: the traditional die casting method and the continuous casting method. The principle of continuous casting is to continuously pour molten metal into a crystallizer and continuously pull it out from the other end of the crystallizer, which can produce materials of any length or a specific length.

[0003] Taking copper-clad steel (also known as copper-coated steel) as an example, it is also called copper-clad steel bimetallic composite material. It is a composite conductor made of copper and steel through a special process. This conductor has both the high strength, excellent elasticity, large thermal resistance and high magnetic permeability of steel, and the good electrical conductivity and excellent corrosion resistance of copper. It is widely used in the electrical and electronic fields.

[0004] In the production of copper-clad steel (CCS) materials, continuous casting, a core production process, is crucial for the quality and production efficiency of CCS products. However, multiple factors can affect the quality and efficiency of CCS continuous casting. Current technologies have not yet proposed an efficient and reliable solution for CCS continuous casting production. Therefore, how to simultaneously achieve high production efficiency, high yield, and reliable and excellent product quality in CCS production is an urgent problem to be solved. Summary of the Invention

[0005] One objective of this disclosure is to provide a horizontal continuous casting control method for copper-clad steel, a horizontal continuous casting system for producing copper-clad steel, and copper-clad steel wire produced therefrom, in order to alleviate or eliminate the aforementioned defects in existing copper-clad steel continuous casting production technology.

[0006] This disclosure discloses a method for controlling horizontal continuous casting of copper-clad steel, characterized in that the continuous casting furnace includes a melting furnace, a connector, and a crystallizer. The melting furnace has an inner cavity and an inlet and an outlet communicating with the inner cavity. The connector is inserted into the inlet of the melting furnace. The inner cavity is adapted to contain molten copper. The crystallizer is inserted into the outlet of the melting furnace. The portion of the crystallizer located in the inner cavity has a casting cavity and a pouring hole communicating with the casting cavity. The inner cavity is connected to both the pouring hole and the casting cavity. The connector is used for feeding steel wire, and the crystallizer is used for discharging copper-clad steel wire.

[0007] The horizontal continuous casting control method includes:

[0008] The level of the molten copper contained in the inner cavity is maintained at a level that is higher than a first predetermined height relative to the steel wire in the continuous casting furnace, wherein the first predetermined height is not less than 5 cm;

[0009] The movement of the steel wire is controlled by feeding it through the connector, passing through the inner cavity of the melting furnace, entering the casting cavity of the crystallizer, and then exiting. The total residence time of the steel wire in the furnace from feeding to exiting is controlled so that the steel wire is heated to a first set temperature when entering the casting cavity of the crystallizer. The first set temperature is a temperature greater than the solidification point of copper liquid and between 1120 and 1220°C. The total residence time in the furnace is between 30 and 90 seconds.

[0010] The molten copper in the inner cavity enters the casting cavity through the filling hole of the crystallizer, thereby causing the molten copper to crystallize on the surface of the steel wire to form copper-clad steel wire.

[0011] The technical solution proposed in this disclosure addresses one of the shortcomings of existing technologies. By appropriately heating the steel wire to a first set temperature using the high temperature of the melting furnace—that is, raising the temperature before entering the crystallizer to cast the copper layer—it is more conducive to the bonding between the molten copper and the surface of the steel wire, improving the coating effect of the copper layer on the steel wire surface and enhancing the continuous casting quality of copper-clad steel wire. Utilizing the coordination of the melting furnace and the crystallizer, the high temperature of the melting furnace acts on both the molten copper and the steel wire, ensuring full utilization of heat. Furthermore, it shortens the distance between the preheating and copper layer casting processes, ensuring that the steel wire immediately enters the casting chamber of the crystallizer after preheating, reducing heat loss between the two processes. Simultaneously, appropriate heating still allows for rapid cooling and surface crystallization after copper coating, further achieving better energy efficiency in copper-clad steel continuous casting production.

[0012] According to some embodiments of this disclosure, the horizontal continuous casting control method includes preheating the steel wire to a second set temperature via a preheating device before the steel wire enters the connector, the second set temperature being between 300 and 800°C.

[0013] According to some embodiments of this disclosure, controlling the movement of the steel wire includes:

[0014] The steel wire is controlled to be conveyed according to a set feeding strategy. The set feeding strategy is a step-by-step conveying strategy that continuously and alternately conveys the steel wire at a set traveling speed, allowing it to travel a set step distance (which can also be understood as the strategy controlling the set traveling speed and indirectly controlling a second set duration for driving the steel wire to travel), and then stops conveying for a first set duration. The total residence time in the furnace is set according to the temperature difference between the temperature of the steel wire before entering the connector and the first set temperature. The first set duration is set according to the crystallization time of the copper liquid on the surface of the steel wire in the casting cavity. The set step distance and the set traveling speed are set in a way that is related to each other, based on the inner cavity length, the total residence time in the furnace, and the first set duration.

[0015] It can be understood that the output frequency and the second set duration of the step-type conveying strategy are related to the first set duration (the latter two determine the duration of a single output cycle), and the overall production speed of the copper-clad steel wire is related to the total residence time in the furnace and the length of the inner cavity (the overall production speed can be calculated from the latter two and measured by the length of the copper-clad steel wire).

[0016] According to some embodiments of this disclosure, the inner cavity length is between 20 and 40 cm, the total residence time in the furnace is between 40 and 60 seconds, and the overall production speed determined by the inner cavity length and the total residence time in the furnace is controlled within the range of 320 mm / min to 540 mm / min.

[0017] According to some preferred embodiments of this disclosure, the first predetermined height of the molten copper contained in the inner cavity is maintained in the range of 10-20 cm, and its temperature is maintained in the range of 1150-1190°C, preferably in the range of 1165-1175°C.

[0018] It should be understood that the molten copper contained in the inner cavity needs to be poured through the injection hole onto the surface of the steel wire in the casting cavity. Therefore, by setting a preferred first predetermined height range, the appropriate amount of static pressure generated by the molten copper level is used to ensure that the molten copper flows into the casting cavity through the injection hole at a desired or optimal flow rate under static pressure, crystallizing on the surface of the steel wire to form copper-clad steel wire. In other words, the preferred first predetermined height helps the molten copper to flow into the casting cavity and fully combine with the steel wire during the first set period of time during which the steel wire is stopped in the aforementioned step-feeding strategy, thereby achieving better product quality of copper-clad steel wire and avoiding product defects.

[0019] According to some preferred embodiments of this disclosure, the horizontal continuous casting control method may further include:

[0020] Based on the desired overall production speed or target production speed, the wire travel speed and copper liquid temperature are adjusted accordingly. Specifically, when the overall production speed is controlled within the range of 320 mm / min to 540 mm / min, if the desired overall production speed is increased, the wire travel speed is increased synchronously, and the copper liquid temperature is increased slightly (within the range of 1150 to 1190°C).

[0021] It should be understood that, according to the horizontal continuous casting control method of the above embodiments of this disclosure, the copper-clad steel continuous casting process is implemented through a stepping system in the stage of pulling out the billet after the furnace. This stepping system provides the time required for the copper cladding layer in the continuous casting furnace to solidify and performs a pull / stop cycle for the metal billet. Therefore, a stepping drive device, such as a stepper motor, is very suitable to serve as the active drive power source and to pull out the copper-clad steel billet in a stepping manner after the furnace. At the same time, since the upstream process of the copper-clad steel continuous casting production line may need to drive the steel to move continuously (for example, uncoiling and straightening in the upstream process may require continuous power output to ensure the processing effect of their own stages), there must be a certain degree of inconsistency between the upstream and downstream power systems in the production line. The horizontal continuous casting control method according to the preferred embodiment of this disclosure, through its specific settings for the continuous casting process, can simultaneously achieve the following two important technical advantages: improving the continuous casting quality of copper-clad steel wire, so that the structural characteristics and conductivity of the produced copper-clad steel wire are particularly suitable for applications such as (underground) electrical grounding grids in industrial facilities, and can also be applied to the above-ground portion of grounding systems or grounding grids, or to lightning protection materials such as lightning rods, strips, nets, wires, and lightning down conductors; improving the production yield of copper-clad steel wire, or reducing or even eliminating the following defects that may occur in the product, such as steel wire breakage, cracking, and copper infiltration (a large amount of copper infiltrating into the steel material) caused by cracking, which may be caused by the aforementioned stepping power system used to pull out the billet after the furnace.

[0022] According to some embodiments of this disclosure, the copper-clad steel wire is used for the construction of electrical grounding grids for industrial facilities, and the cross-sectional area of ​​the copper-clad steel wire is in the range of 50-400 square millimeters.

[0023] According to some embodiments of this disclosure, the horizontal continuous casting control method may further include:

[0024] Obtain the quality information of the copper-clad steel wire at the outlet of the crystallizer;

[0025] If the quality information does not meet the (set) desired conditions, at least one of the following is adjusted: the wire travel speed, the cooling medium flow rate of the connector, and the cooling medium flow rate of the crystallizer. Specifically, adjusting at least one of the following can include:

[0026] Based on the relationship between the current temperature of the molten copper in the melting furnace and the first set temperature, at least one of the following is adjusted: the traveling speed of the steel wire and the flow rate of the cooling medium in the connector.

[0027] This disclosure also provides a horizontal continuous casting system for producing copper-clad steel, characterized in that the horizontal continuous casting system includes:

[0028] A continuous casting furnace includes a melting furnace, a connector, and a crystallizer. The melting furnace has an inner cavity and an inlet and an outlet communicating with the inner cavity. The inner cavity is adapted to contain molten copper. The melting furnace has a rotating mechanism configured to operably rotate the melting furnace, thereby raising or lowering the level of the molten copper contained therein by tilting the inner cavity, and maintaining the level of the molten copper at a level higher than the steel wire in the continuous casting furnace by a first predetermined height, wherein the first predetermined height is not less than 5 cm.

[0029] A connector is inserted into the inlet of the melting furnace and used for feeding steel wire;

[0030] A crystallizer is inserted at the outlet of the melting furnace. The portion of the crystallizer located in the inner cavity is provided with a casting chamber and a pouring hole communicating with the casting chamber. The inner cavity is connected to both the pouring hole and the casting chamber. The molten copper in the inner cavity can enter the casting chamber through the pouring hole of the crystallizer, thereby causing the molten copper to crystallize on the surface of the steel wire to form copper-clad steel wire and realize the discharge of copper-clad steel wire.

[0031] A wire conveying device is configured to control the movement of a wire, which is fed through the connector, passes through the inner cavity of the melting furnace, enters the casting cavity of the crystallizer, and is then discharged. The total residence time of the wire in the furnace from feeding to discharge is controlled such that the wire is heated to a first set temperature when it enters the casting cavity of the crystallizer. The first set temperature is a temperature greater than the solidification point of molten copper and is between 1120 and 1220°C. The total residence time in the furnace is between 30 and 90 seconds.

[0032] According to some embodiments of this disclosure, the horizontal continuous casting system further includes:

[0033] A preheating device is arranged before the connector and configured to preheat the steel wire to a second set temperature, which is between 300 and 800°C.

[0034] According to some embodiments of this disclosure, the wire conveying device includes a controller and a conveying assembly controlled by the controller. The controller is configured with a set feeding strategy and is able to control the conveying assembly to execute the set feeding strategy to convey the wire.

[0035] The feeding strategy is a step-by-step feeding strategy that continuously and alternately feeds the steel wire at a set speed, allowing it to travel a set step distance before stopping for a first set time. The total residence time in the furnace is set based on the temperature difference between the temperature of the steel wire before entering the connector and the first set temperature. The first set time is set based on the crystallization time of the copper liquid on the surface of the steel wire in the casting cavity. The set step distance and the set travel speed are set in a correlated manner based on the inner cavity length, the total residence time in the furnace, and the first set time.

[0036] According to some embodiments of this disclosure, the inner cavity length is between 20 and 40 cm, the total residence time in the furnace is between 40 and 60 seconds, and the overall production speed determined by the inner cavity length and the total residence time in the furnace is controlled within the range of 320 mm / min to 540 mm / min.

[0037] According to some embodiments of this disclosure, the rotating mechanism is configured to operably rotate the melting furnace, thereby maintaining the level of the molten copper contained therein at a first predetermined height relative to the steel wire in the continuous casting furnace within a range of 10-20 cm by tilting the inner cavity, and the melting furnace is configured to maintain the temperature of the molten copper contained therein within a range of 1150-1190°C, preferably within a range of 1165-1175°C.

[0038] According to some embodiments of this disclosure, the conveying assembly includes a front-end pushing mechanism disposed in front of the connector and a rear-end pulling mechanism disposed behind the crystallizer, wherein the rear-end pulling mechanism includes a stepping second driver and a second transmission assembly, and is configured such that the copper-clad steel wire is discharged in a stepping conveying strategy, and the front-end pushing mechanism includes a continuous first driver and a first transmission assembly, wherein the first transmission assembly allows slippage between itself and the steel wire so that the first driver drives the steel wire in a manner that cooperates with the second driver.

[0039] According to some embodiments of this disclosure, the copper-clad steel wire is used for the construction of electrical grounding grids for industrial facilities, and the cross-sectional area of ​​the copper-clad steel wire is in the range of 50-400 square millimeters.

[0040] This disclosure also provides a horizontal continuous casting control method for copper-clad steel as described above or copper-clad steel wire produced by a horizontal continuous casting system for producing copper-clad steel as described above, characterized in that the copper-clad steel wire consists of the following three parts radially from the inside to the outside: a steel core, a copper-steel transition layer and an outer copper cladding layer.

[0041] The content of elements other than copper and iron mixed in the copper-steel transition layer is negligible, and the thickness of the copper-steel transition layer is in the range of 2-15 micrometers.

[0042] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present disclosure.

[0043] The positive and progressive effects of this disclosure are as follows:

[0044] The horizontal continuous casting control method for copper-clad steel according to this disclosure, the horizontal continuous casting system for producing copper-clad steel, and the copper-clad steel wire produced therefrom can at least to some extent combine the high production efficiency, high yield, and reliable and excellent performance of copper-clad steel wire. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the continuous casting furnace used in a horizontal continuous casting control method for copper-clad steel according to an embodiment of the present disclosure.

[0046] Figure 2 The compositional levels of the copper-steel transition zone of copper-clad steel wire produced by a horizontal continuous casting control method according to a further preferred embodiment of the present disclosure are shown by scanning electron microscopy analysis.

[0047] Explanation of reference numerals in the attached figures:

[0048] 31. Melting furnace; 311. Inner cavity; 32. Crystallizer; 321. Casting cavity; 322. Pouring hole; 33. Connector; 4. Preheating device; 8. Steel wire; 10. Molten copper Detailed Implementation

[0049] The preferred embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings. The following description is exemplary and not intended to limit the scope of this disclosure. Any other similar situations also fall within the protection scope of this disclosure.

[0050] In the following detailed description, directional terms such as "left," "right," "up," "down," "front," "back," etc., are used with reference to the directions described in the accompanying drawings. Components of embodiments of this disclosure may be positioned in a variety of different orientations, and the directional terms are for illustrative purposes and not for limitation.

[0051] Before describing the preferred embodiment of the horizontal continuous casting control method for copper-clad steel, the production process of copper-clad steel will be described first. After the steel is cut by the cutting mechanism, the steel wire to be processed enters the straightening mechanism for straightening, and then enters the polishing mechanism for polishing. After polishing, it is preheated by the preheating device and then enters the continuous casting furnace. The steel wire to be processed is coated with a copper layer in the continuous casting furnace. The copper-clad steel wire is pulled out of the continuous casting furnace and then cooled by the cooling device, thus completing the copper-clad steel process.

[0052] refer to Figure 1 As shown, the continuous casting furnace includes a melting furnace 31 and a crystallizer 32. The melting furnace 31 has an inner cavity 311 and an inlet and an outlet communicating with the inner cavity 311. A connector 33 is inserted into the inlet of the melting furnace 31. The inner cavity 311 is adapted to contain molten copper 10. The crystallizer 32 is inserted into the outlet of the melting furnace 31. The portion of the crystallizer 32 located in the inner cavity 311 has a casting cavity 321 and a pouring hole 322. The inner cavity 311 communicates with the casting cavity 321 through the pouring hole 322, so that the steel wire 8 entering the inner cavity 311 through the connector 33 passes through the casting cavity 321. The molten copper 10 enters the casting cavity 321 through the pouring hole 322 and is cast onto the surface of the steel wire 8 to form copper-clad steel wire.

[0053] Specifically, still refer to Figure 1 As shown, a method for controlling horizontal continuous casting of copper-clad steel according to one embodiment of this disclosure includes:

[0054] The copper liquid 10 contained in the inner cavity 311 is kept at a level that is higher than the steel wire 8 in the continuous casting furnace by a first predetermined height, wherein the first predetermined height is not less than 5 cm.

[0055] The movement of the steel wire 8 is controlled by the connector 33, which feeds the steel wire 8 through the inner cavity 311 of the melting furnace 31 and into the casting cavity 321 of the crystallizer 32 before discharging it. The total residence time of the steel wire 8 in the furnace from feeding to discharging is controlled so that the steel wire 8 is heated to a first set temperature when it enters the casting cavity 321 of the crystallizer 32. The first set temperature is a temperature greater than the solidification point of the copper liquid 10 and between 1120 and 1220°C. The total residence time in the furnace is between 30 and 90 seconds.

[0056] The copper liquid 10 in the inner cavity 311 enters the casting cavity 321 through the injection hole 322 of the crystallizer 32, thereby causing the copper liquid 10 to crystallize on the surface of the steel wire 8 to form copper-clad steel wire.

[0057] The solution provided by the above embodiment can appropriately heat the steel wire 8 to a first set temperature through the high temperature of the melting furnace 31, that is, raise the temperature before entering the crystallizer 32 for copper coating. This is more conducive to the bonding between the copper liquid 10 and the surface of the steel wire 8, improves the coating effect of the copper layer on the surface of the steel wire 8, and improves the continuous casting quality of copper-clad steel wire. The cooperation between the melting furnace 31 and the crystallizer 32 allows the high temperature of the melting furnace 31 to act on the copper liquid 10 and the steel wire 8 at the same time, making full use of the heat. It also shortens the distance between the preheating and copper layer casting processes, ensuring that the steel wire 8 enters the casting chamber 321 of the crystallizer 32 immediately after preheating, reducing the heat loss of the steel wire 8 between the two processes. At the same time, appropriate heating still allows the copper layer to cool down relatively quickly after coating to complete the surface crystallization process, further achieving better energy efficiency in copper-clad steel continuous casting production.

[0058] According to some preferred embodiments of the present disclosure, the horizontal continuous casting control method includes preheating the steel wire 8 to a second set temperature via a preheating device 4 before the steel wire 8 enters the connector 33, the second set temperature being between 300 and 800°C.

[0059] More specifically, before the steel wire 8 enters the inner cavity 311 of the melting furnace 31 through the inlet, and before the steel wire 8 is preheated to the set temperature by the melting furnace 31, the process also includes:

[0060] Control the steel wire 8 to enter the preheating device 4 for initial preheating to the second set temperature;

[0061] The control steel wire 8 enters the connector 33 from the preheating device 4.

[0062] In this embodiment, before the driving device drives the steel wire 8 into the melting furnace 31, the steel wire 8 first passes through the preheating device 4 to perform initial preheating, and then enters the inner cavity 311 of the melting furnace 31 for secondary heating. The initial preheating raises the temperature of the steel wire 8 to a second set temperature, and the second preheating raises the temperature of the steel wire 8 to a first set temperature. The steel wire 8 gradually heats up while moving, which can extend the heating path of the steel wire 8. While maintaining a certain traveling speed, the preheating temperature of the steel wire 8 can be achieved, ensuring the quality of the cast copper of the steel wire 8. At the same time, multiple preheatings can keep the steel wire 8 at a certain traveling speed, avoiding the steel wire 8 from staying in one process for a long time to preheat in order to reach the required preheating temperature.

[0063] The horizontal continuous casting control method according to the above embodiments of this disclosure preheats the steel wire 8 to a first set temperature using the high temperature of the melting furnace 31. This temperature increase before the copper layer is cast in the crystallizer 32 is achieved is more conducive to the bonding between the molten copper 10 and the surface of the steel wire 8, improving the coating effect of the copper layer on the surface of the steel wire 8 and enhancing the continuous casting quality of the copper-clad steel wire. By utilizing the cooperation between the melting furnace 31 and the crystallizer 32, the high temperature of the melting furnace 31 acts on both the molten copper 10 and the steel wire 8, ensuring full utilization of heat and shortening the distance between the preheating and copper layer casting processes. This ensures that the steel wire 8 enters the casting chamber 321 of the crystallizer 32 immediately after preheating, reducing heat loss between the two processes. The molten copper 10 directly enters the casting chamber 321 of the crystallizer 32 from the inner cavity 311 of the melting furnace 31, integrating the processes of copper melting, steel wire 8 preheating, and copper layer casting into one continuous casting furnace, resulting in a more compact and integrated horizontal continuous casting control.

[0064] Moreover, the continuous casting furnace is based on the horizontal continuous casting process. The inlet and outlet of the melting furnace 31 are set opposite each other in the horizontal direction. A crystallizer 32 is set at the outlet. The lowest vertical liquid level of the copper liquid 10 is located at the bottom of the melting furnace 31, and the highest vertical liquid level of the copper liquid 10 submerges the crystallizer 32.

[0065] According to some preferred embodiments of this disclosure, controlling the movement of the steel wire 8 includes:

[0066] The steel wire 8 is controlled to be conveyed according to a set feeding strategy. The set feeding strategy is a step-by-step conveying strategy that continuously and alternately conveys the steel wire at a set traveling speed, and then stops conveying for a first set time after traveling a set step distance. The total residence time in the furnace is set according to the temperature difference between the temperature of the steel wire 8 before entering the connector 33 and the first set temperature. The first set time is set according to the crystallization time of the copper liquid 10 on the surface of the steel wire 8 in the casting cavity 321. The set step distance and the set traveling speed are set in a way that is related to each other, based on the length of the inner cavity 311, the total residence time in the furnace, and the first set time.

[0067] It is understood that the output frequency of the step-type conveying strategy and the second set duration are related to the first set duration (the latter two determine the duration of a single output cycle). The overall production speed of the copper-clad steel wire can be calculated based on the total residence time in the furnace and the length of the inner cavity 311. The overall production speed is measured by the length of copper-clad steel wire produced per unit time, and the unit is, for example, millimeters per minute.

[0068] According to some preferred embodiments of this disclosure, the length of the inner cavity 311 is between 20 and 40 cm, the total residence time in the furnace is between 40 and 60 seconds, and the overall production speed determined by the length of the inner cavity 311 and the total residence time in the furnace is controlled within the range of 320 mm / min to 540 mm / min.

[0069] According to some further preferred embodiments of this disclosure, the first predetermined height of the molten copper 10 contained in the inner cavity 311 is maintained in the range of 10-20 cm, and its temperature is maintained in the range of 1150-1190°C, preferably in the range of 1165-1175°C.

[0070] According to a further preferred embodiment of this disclosure, the horizontal continuous casting control method may further include:

[0071] Based on the desired overall production speed or target production speed, the wire travel speed and copper liquid temperature are adjusted accordingly. Specifically, when the overall production speed is controlled within the range of 320 mm / min to 540 mm / min, if the desired overall production speed is increased, the wire travel speed is increased synchronously, and the copper liquid temperature is increased slightly (within the range of 1150 to 1190°C).

[0072] The horizontal continuous casting control method according to the above-described preferred embodiments of this disclosure, through its specific settings for the continuous casting process, can simultaneously achieve the following two important technical advantages: improving the continuous casting quality of copper-clad steel wire, so that the structural characteristics and conductivity of the produced copper-clad steel wire are particularly suitable for applications such as (underground) electrical grounding grids in industrial facilities; and improving the production yield of copper-clad steel wire, or reducing or even eliminating the following defects that may occur in the product, such as the steel wire 8 being broken, cracked, and copper infiltration (a large amount of copper infiltrating into the steel material) caused by cracking, which may be caused by the aforementioned stepping power system used to pull out the billet after the furnace.

[0073] The copper-clad steel wire produced by the horizontal continuous casting control method of the further preferred embodiment of the present disclosure consists of the following three parts radially from the inside out: a steel core, a copper-steel transition layer, and an outer copper cladding layer; wherein, the content of elements other than copper and iron mixed in the copper-steel transition layer (i.e., the copper-steel interpenetration layer) is negligible, and the thickness of the copper-steel transition layer is in the range of 2-15 micrometers.

[0074] and, Figure 2 Specifically, the compositional levels of the copper-steel transition zone of the copper-clad steel wire produced by this preferred method, as shown by scanning electron microscopy analysis, exhibit the following characteristics:

[0075] (1) The copper-steel transition zone basically contains only copper and iron elements but no nickel elements (the transition zone of the copper-steel composite formed by electroplating process contains a large amount of nickel elements), and in fact, an interpenetrating layer of copper and steel molecules is formed.

[0076] (2) The copper-steel transition layer contains copper and iron elements with relatively high content, and the thickness of the transition layer reaches about 20 micrometers. This transition zone thickness exceeds the transition zone thickness of copper-clad steel wire produced by existing technology.

[0077] (3) Copper-clad steel wire has a high hardness after rolling, with a Vickers hardness of about 130 or above.

[0078] The above characteristics (1)-(3) further enable the copper-clad steel wire product to have a strong bonding force between copper and steel, making it less prone to copper layer peeling or copper-steel separation when subjected to external forces (such as bending). This also allows for subsequent rolling and drawing processes to change the product's diameter, during which the copper and steel layers deform synchronously, especially due to the aforementioned superior copper-steel bonding force. Furthermore, the copper-clad steel wire product can withstand high-frequency current impacts without blistering or peeling, contributing to its long-term reliability in industrial grounding applications.

[0079] For example, according to some preferred embodiments of the present disclosure, the copper-clad steel wire, especially the copper-clad steel product having the above characteristics (1)-(3), can be used for the construction of electrical grounding grids for industrial facilities, and the cross-sectional area of ​​the copper-clad steel wire is preferably in the range of 50-400 square millimeters, or the diameter of the steel wire 8 is in the range of 10-50 millimeters, and optionally, for the more widespread underground electrical grounding grids for industrial facilities, the diameter of the steel wire 8 is preferably in the range of 12-18 millimeters.

[0080] The following sections will further introduce several specific embodiments for further controlling the quality of copper-clad steel wire rod based on the horizontal continuous casting control method embodiments described above.

[0081] According to a further preferred embodiment of the present disclosure, the horizontal continuous casting control method for copper-clad steel also includes:

[0082] Obtain quality information of the copper-clad steel wire at the outlet of crystallizer 32;

[0083] If the quality information does not meet the expected conditions, adjust at least one of the following: the travel speed of the steel wire 8, the cooling medium flow rate of the connector 33, and the cooling medium flow rate of the crystallizer 32.

[0084] In this embodiment, the step of obtaining the quality information of the copper-clad steel wire output from the outlet of the crystallizer 32 involves installing a device for obtaining quality information at the outlet of the crystallizer 32. This ensures that the crystallizer 32 immediately obtains the quality information when it outputs the copper-clad steel wire, so as to adjust the various devices of the copper-clad steel production line in a timely manner and ensure production accuracy and quality.

[0085] The quality information does not meet the expected conditions, meaning the quality of the copper-clad steel wire is substandard. This can be understood in the following ways: 1. The copper layer thickness does not meet the set thickness requirements, such as the overall thickness of the copper layer not meeting the set thickness, or the thickness of the copper layer in a localized area not meeting the set thickness; 2. The copper layer crystal quality does not meet the set requirements, such as uneven copper layer crystallization, cracks, slag inclusions, or exposed steel. Among these, copper layer thickness and copper layer crystallization are related but also independent. Uneven copper layer thickness can lead to exposed steel, and poor copper layer crystallization quality can also lead to exposed steel.

[0086] The quality of copper-clad steel wire is affected by various processing devices such as melting furnace 31, crystallizer 32, preheating device 4, and driving device. If the quality of copper-clad steel wire is found to be substandard, the melting furnace 31, crystallizer 32, preheating device 4, and driving device are checked and adjusted to quickly adjust the quality of copper-clad steel wire and ensure that the quality of copper-clad steel wire meets production requirements.

[0087] According to some embodiments of this disclosure, in the horizontal continuous casting control method, if the quality information is determined not to meet the expected conditions, such as determining that the copper layer thickness has not reached the set thickness or that the copper layer crystallization produces at least one of the following defects: cracks, inclusions, or exposed steel, then the wire travel speed is adjusted, the wire entry position is adjusted, and the wire travel is stabilized to reduce irregular vibrations of the wire.

[0088] The following describes an embodiment of the horizontal continuous casting system for producing copper-clad steel provided in this disclosure. The horizontal continuous casting system for producing copper-clad steel and the superior technical effects it can achieve described below are to be understood and referred to in correspondence with the embodiment of the horizontal continuous casting control method for copper-clad steel described above.

[0089] Still referencing Figure 1 As shown, this disclosure also provides a horizontal continuous casting system for producing copper-clad steel, comprising:

[0090] A continuous casting furnace includes a melting furnace 31, a connector 33, and a crystallizer 32. The melting furnace 31 has an inner cavity 311 and an inlet and an outlet communicating with the inner cavity 311. The inner cavity 311 is adapted to contain molten copper 10. The melting furnace 31 has a rotating mechanism configured to operably rotate the melting furnace 31, thereby raising or lowering the level of the molten copper 10 contained therein by tilting the inner cavity 311, and maintaining the level of the molten copper 10 at a level higher than the steel wire 8 in the continuous casting furnace by a first predetermined height, wherein the first predetermined height is not less than 5 cm.

[0091] Connector 33 is inserted into the inlet of the melting furnace 31 and used for feeding steel wire 8;

[0092] A crystallizer 32 is inserted at the outlet of the melting furnace 31. The portion of the crystallizer 32 located in the inner cavity 311 is provided with a casting cavity 321 and a pouring hole 322 communicating with the casting cavity 321. The inner cavity 311 is connected to both the pouring hole 322 and the casting cavity 321. The copper liquid 10 in the inner cavity 311 can enter the casting cavity 321 through the pouring hole 322 of the crystallizer 32, thereby causing the copper liquid 10 to crystallize on the surface of the steel wire 8 to form copper-clad steel wire and realize the discharge of copper-clad steel wire.

[0093] A steel wire 8 conveying device is configured to control the movement of the steel wire 8. The steel wire 8 is fed through the connector 33, passes through the inner cavity 311 of the melting furnace 31, enters the casting cavity 321 of the crystallizer 32, and is then discharged. The total residence time of the steel wire 8 in the furnace from feeding to discharge is controlled such that the steel wire 8 is heated to a first set temperature when it enters the casting cavity 321 of the crystallizer 32. The first set temperature is a temperature greater than the solidification point of the copper liquid 10 and between 1120 and 1220°C. The total residence time in the furnace is between 30 and 90 seconds.

[0094] According to a preferred embodiment of this disclosure, the horizontal continuous casting system further includes:

[0095] A preheating device 4 is arranged in front of the connector 33 and configured to preheat the steel wire 8 to a second set temperature, which is between 300 and 800°C.

[0096] According to a preferred embodiment of the present disclosure, the steel wire 8 conveying device includes a controller and a conveying component controlled by the controller. The controller is configured with a set feeding strategy and is able to control the conveying component to execute the set feeding strategy to convey the steel wire 8.

[0097] The feeding strategy is a step-by-step feeding strategy that continuously and alternately feeds the steel wire at a set speed, allowing it to travel a set step distance before stopping for a first set duration. The total residence time in the furnace is set based on the temperature difference between the temperature of the steel wire 8 before entering the connector 33 and the first set temperature. The first set duration is set based on the crystallization time of the copper liquid 10 on the surface of the steel wire 8 in the casting cavity 321. The set step distance and the set travel speed are set in a correlated manner based on the length of the inner cavity 311, the total residence time in the furnace, and the first set duration.

[0098] According to a preferred embodiment of this disclosure, the length of the inner cavity 311 is between 20 and 40 centimeters, the total residence time in the furnace is between 40 and 60 seconds, and the overall production speed determined by the length of the inner cavity 311 and the total residence time in the furnace is controlled within the range of 320 mm / min to 540 mm / min.

[0099] According to a preferred embodiment of this disclosure, the rotating mechanism is configured to operably rotate the melting furnace 31, thereby maintaining the level of the molten copper 10 contained therein at a first predetermined height relative to the steel wire 8 in the continuous casting furnace within a range of 10-20 cm by tilting the inner cavity 311, and the melting furnace 31 is configured to maintain the temperature of the molten copper 10 contained therein within a range of 1150-1190°C, preferably within a range of 1165-1175°C.

[0100] According to a preferred embodiment of the present disclosure, the conveying assembly includes a front-end pushing mechanism disposed in front of the connector 33 and a rear-end pulling mechanism disposed behind the crystallizer 32, wherein the rear-end pulling mechanism includes a stepping second driver and a second transmission assembly, and is configured such that the copper-clad steel wire is discharged in a stepping conveying strategy, and the front-end pushing mechanism includes a continuous first driver and a first transmission assembly, wherein the first transmission assembly allows slippage between itself and the steel wire 8 so that the first driver drives the steel wire 8 in a manner that cooperates with the second driver.

[0101] According to a preferred embodiment of this disclosure, the copper-clad steel wire is used for the construction of an electrical grounding grid for industrial facilities, and the diameter of the steel wire 8 is in the range of 10-50 mm.

[0102] The horizontal continuous casting system for producing copper-clad steel according to the preferred embodiments described above is also capable of producing products as described above. Figure 2 The properties or characteristics of copper-clad steel wire described herein will not be elaborated upon here.

[0103] While specific embodiments of this disclosure have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this disclosure is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this disclosure, and all such changes and modifications shall fall within the scope of protection of this disclosure.

Claims

1. A method for controlling horizontal continuous casting of copper-clad steel, characterized in that, The continuous casting furnace includes a melting furnace, a connector, and a crystallizer. The melting furnace has an inner cavity and an inlet and an outlet communicating with the inner cavity. The connector is inserted into the inlet of the melting furnace. The inner cavity is adapted to contain molten copper. The crystallizer is inserted into the outlet of the melting furnace. The portion of the crystallizer located in the inner cavity has a casting chamber and a pouring hole communicating with the casting chamber. The inner cavity is connected to both the pouring hole and the casting chamber. The connector is used for feeding steel wire, and the crystallizer is used for discharging copper-clad steel wire. The surface of the steel wire does not contain an additional nickel coating, so that the discharging copper-clad steel wire contains an interpenetrating layer of interwoven copper and steel molecules. The horizontal continuous casting control method includes: The level of the molten copper contained in the inner cavity is maintained at a level that is higher than a first predetermined height relative to the steel wire in the continuous casting furnace, wherein the first predetermined height is not less than 5 cm; The movement of the steel wire is controlled by feeding it through the connector, passing through the inner cavity of the melting furnace, entering the casting cavity of the crystallizer, and then exiting. The total residence time of the steel wire in the furnace from feeding to exiting is controlled so that the steel wire is heated to a first set temperature when entering the casting cavity of the crystallizer. The first set temperature is a temperature greater than the solidification point of copper liquid and between 1120 and 1220°C. The total residence time in the furnace is between 30 and 90 seconds. The molten copper in the inner cavity enters the casting cavity through the filling hole of the crystallizer, thereby causing the molten copper to crystallize on the surface of the steel wire to form copper-clad steel wire. The control of the steel wire's movement includes: The steel wire is controlled to be conveyed according to a set feeding strategy. This set feeding strategy is a step-feeding strategy that continuously and alternately conveys the steel wire at a set traveling speed, stopping after traveling a set step distance for a first set time. The total residence time in the furnace is set based on the temperature difference between the temperature of the steel wire before entering the connector and the first set temperature. The first set time is set based on the crystallization time of the molten copper on the surface of the steel wire in the casting cavity. The set step distance and the set traveling speed are set in a correlated manner based on the inner cavity length, the total residence time in the furnace, and the first set time. Furthermore, the inner cavity length is between 20-40 cm, the total residence time in the furnace is between 40-60 seconds, and the overall production speed determined by the inner cavity length and the total residence time in the furnace is controlled within the range of 320 mm / min-540 mm / min. By tilting the inner cavity, the copper liquid level contained therein is kept within a first predetermined height of 10-20 cm above the steel wire in the continuous casting furnace, thereby utilizing the copper liquid level height to generate an appropriate amount of static pressure to ensure that the copper liquid flows into the casting cavity through the pouring hole at the desired or optimal flow rate under the action of static pressure, and its temperature is maintained within the range of 1150~1190℃.

2. The horizontal continuous casting control method for copper-clad steel according to claim 1, characterized in that, The horizontal continuous casting control method includes preheating the steel wire to a second set temperature via a preheating device before the steel wire enters the connector. The second set temperature is between 300 and 800°C.

3. The horizontal continuous casting control method for copper-clad steel according to claim 1, characterized in that, The temperature of the molten copper contained in the inner cavity is maintained within the range of 1165-1175℃.

4. The horizontal continuous casting control method for copper-clad steel according to any one of claims 1-3, characterized in that, The copper-clad steel wire is used for the construction of electrical grounding grids for industrial facilities, and the cross-sectional area of ​​the copper-clad steel wire is in the range of 50-400 square millimeters.

5. A horizontal continuous casting system for producing copper-clad steel, characterized in that, The horizontal continuous casting system includes: A continuous casting furnace includes a melting furnace, a connector, and a crystallizer. The melting furnace has an inner cavity and an inlet and an outlet communicating with the inner cavity. The inner cavity is adapted to contain molten copper. The melting furnace has a rotating mechanism configured to operably rotate the melting furnace, thereby raising or lowering the level of the molten copper contained therein by tilting the inner cavity, and maintaining the level of the molten copper at a level higher than the steel wire in the continuous casting furnace by a first predetermined height, wherein the first predetermined height is not less than 5 cm. A connector is inserted into the inlet of the melting furnace and used for feeding steel wire; A crystallizer is inserted at the outlet of the melting furnace. The portion of the crystallizer located in the inner cavity is provided with a casting chamber and a pouring hole communicating with the casting chamber. The inner cavity is connected to both the pouring hole and the casting chamber. The molten copper in the inner cavity can enter the casting chamber through the pouring hole of the crystallizer, thereby causing the molten copper to crystallize on the surface of the steel wire to form copper-clad steel wire and realize the discharge of copper-clad steel wire. A wire conveying device is configured to control the movement of the wire. The wire is fed through the connector, passes through the inner cavity of the melting furnace, enters the casting cavity of the crystallizer, and then exits. The total residence time of the wire in the furnace from feeding to discharge is controlled such that the wire is heated to a first set temperature upon entering the casting cavity of the crystallizer. This first set temperature is greater than the solidification point of molten copper and is between 1120 and 1220°C. The total residence time in the furnace is between 30 and 90 seconds. The steel wire conveying device includes a controller and a conveying assembly controlled by the controller. The controller is configured with a set feeding strategy and can control the conveying assembly to execute the set feeding strategy to convey the steel wire. The feeding strategy is a step-by-step feeding strategy that continuously and alternately feeds the steel wire at a set speed, allowing it to travel a set step distance before stopping for a first set time. The total residence time in the furnace is set based on the temperature difference between the steel wire's temperature before entering the connector and the first set temperature. The first set time is set based on the crystallization time of the molten copper on the steel wire surface in the casting cavity. The set step distance and the set travel speed are set in a correlated manner based on the inner cavity length, the total residence time in the furnace, and the first set time. The inner cavity length is between 20-40 cm, and the total residence time in the furnace is between 40-60 seconds. The overall production speed, determined by the inner cavity length and the total residence time in the furnace, is controlled within the range of 320 mm / min to 540 mm / min. The rotating mechanism is configured to operably rotate the melting furnace, thereby tilting the inner cavity to maintain the copper molten metal level within it at a first predetermined height relative to the steel wire in the continuous casting furnace within a range of 10-20 cm. This utilizes the copper molten metal level height to generate an appropriate amount of static pressure, ensuring that the copper molten metal flows into the casting cavity through the grouting hole at a desired or optimal flow rate under static pressure. Furthermore, the melting furnace is configured to maintain the temperature of the copper molten metal within it within the range of 1150-1190°C. The surface of the steel wire does not contain an additional nickel coating, so that the output of the copper-clad steel wire contains an interpenetrating layer in which copper and steel molecules are interwoven.

6. The horizontal continuous casting system for producing copper-clad steel according to claim 5, characterized in that, The horizontal continuous casting system also includes: A preheating device is arranged before the connector and configured to preheat the steel wire to a second set temperature, which is between 300 and 800°C.

7. The horizontal continuous casting system for producing copper-clad steel according to claim 5, characterized in that, The melting furnace is configured to maintain the temperature of the molten copper contained therein within the range of 1165-1175°C.

8. The horizontal continuous casting system for producing copper-clad steel according to claim 5, characterized in that, The conveying assembly includes a front-end pushing mechanism disposed in front of the connector and a rear-end pulling mechanism disposed behind the crystallizer. The rear-end pulling mechanism includes a stepping second driver and a second transmission assembly, and is configured to cause the copper-clad steel wire to be discharged in a stepping conveying strategy. The front-end pushing mechanism includes a continuous first driver and a first transmission assembly. The first transmission assembly allows slippage between itself and the steel wire, thereby causing the first driver to drive the steel wire in a manner that cooperates with the second driver.

9. The horizontal continuous casting system for producing copper-clad steel according to any one of claims 5-8, characterized in that, The copper-clad steel wire is used for the construction of electrical grounding grids for industrial facilities, and the cross-sectional area of ​​the copper-clad steel wire is in the range of 50-400 square millimeters.

10. A method for controlling horizontal continuous casting of copper-clad steel according to any one of claims 1-4, or a method for producing copper-clad steel wire according to any one of claims 5-9, characterized in that, The copper-clad steel wire consists of three parts radially from the inside to the outside: a steel core, a copper-steel transition layer, and an outer copper cladding layer. The content of elements other than copper and iron mixed in the copper-steel transition layer is negligible, and the thickness of the copper-steel transition layer is in the range of 2-15 micrometers.

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