A precision continuous rolling line, a continuous rolling method and application for titanium alloy bar wire

Abstract

This invention belongs to the field of titanium alloy rolling technology, and specifically relates to a precision continuous rolling line, continuous rolling method, and application for titanium alloy bars and wires. The apparatus includes a heating furnace, a billet mill, an online reheating furnace, a two-roll short-stress mill, and a sizing mill group arranged sequentially along the same axis. Behind the sizing mill group are a bar path rolling line and a wire path rolling line. The bar path rolling line includes a water-cooled coiler I arranged sequentially along the same axis. The wire path rolling line includes a water-cooled modular mill, a wire sizing mill group, a cooling bed, and a coiler II arranged sequentially along the same axis. This invention achieves precision rolling while controlling the temperature of the rolled product within the range of -70℃ to 30℃, solving the problems of poor precision and difficulty in controlling dimensional tolerances in existing production lines, and providing reliable process support for the efficient and precise production of titanium alloy bars and wires.

Description

Technical Field

[0001] This invention belongs to the field of titanium alloy rolling technology, and specifically relates to a precision continuous rolling line, continuous rolling method and application for titanium alloy bars and wires. Background Technology

[0002] Titanium alloy bars and wires are key materials in aerospace, biomedicine, and other fields, requiring extremely high dimensional accuracy and microstructure properties. Existing two-roll continuous rolling processes for producing titanium alloys have significant drawbacks: uneven deformation leads to large differences in microstructure and properties between the core and surface layers, making coarse grains and cracks more likely; control of roll width is difficult, resulting in low dimensional accuracy and numerous surface defects; and to prevent cracking, the pass rate is low, leading to a long production process, low efficiency, and high costs.

[0003] In recent years, although new technologies such as three-roll rolling have been developed to improve deformation uniformity and dimensional accuracy, the temperature rise during deformation is too rapid when using three-roll rolling alone. Furthermore, its ability to break up the as-cast structure with large reductions during the roughing stage is inferior to that of a two-roll mill, making it difficult to fully utilize the advantages of each rolling stage. Therefore, how to overcome the limitations of a single roll system and integrate the advantages of different roll systems to achieve efficient and precise rolling of titanium alloy bars and wires has become a critical technological bottleneck that the industry urgently needs to overcome. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a precision continuous rolling line, continuous rolling method, and application for titanium alloy bars and wires. This invention achieves precision rolling while controlling the temperature of the rolled piece within the range of -70℃ to 30℃ at the end of the rolling process, thus solving the problems of poor precision and difficulty in controlling dimensional tolerances in existing production lines. This provides reliable process support for the efficient and precise production of titanium alloy bars and wires.

[0005] The technical solution of the present invention is as follows: a precision continuous rolling line for titanium alloy bars and wires, comprising a heating furnace, a billet mill, an online reheating furnace, a two-roll short-stress mill, and a sizing mill group arranged sequentially along the same axis. A bar path rolling line and a wire path rolling line are respectively arranged behind the sizing mill group. The bar path rolling line includes a water cooler and a coiler I arranged sequentially along the same axis. The wire path rolling line includes a water cooler, a modular mill, a wire sizing mill group, a cooling bed, and a coiler II arranged sequentially along the same axis.

[0006] The heating furnace is a multi-zone gas-fired heating furnace or a resistance heating furnace, or a combination of a gas-fired heating furnace, a resistance heating furnace, and an induction heating furnace.

[0007] The billet mill is a reciprocating horizontally movable rolling mill, a three-roll Lauter mill, a transverse rolling mill, or a multi-stand two-roll mill.

[0008] The sizing mill is a high-rigidity two-roll sizing mill, a high-rigidity three-roll sizing mill, or a high-rigidity four-roll sizing mill.

[0009] Temperature monitoring modules are installed at the inlet and outlet of the billet mill, the two-roll short-stress mill, the sizing mill group and the modular mill. The temperature monitoring modules use a combination of infrared thermometry and thermocouples to collect real-time temperature distribution data of the head, middle and tail of the rolled piece.

[0010] A precision continuous rolling line method for titanium alloy bars and wires, using a precision continuous rolling line for titanium alloy bars and wires as described above, includes the following steps: S1: Heat the titanium alloy billet to the set temperature in a heating furnace, and control the temperature difference between the core and surface of the billet cross section to be less than 10℃; S2: The heated billet is initially rolled using a billet mill to form a rough rolled billet; S3: Use an online reheating furnace to reheat and maintain the temperature of the rolled piece after billet opening, so that its temperature is kept within the appropriate deformation range of titanium alloy; S4: The workpiece is further rolled using a two-roll short-stress rolling mill to reduce the cross-section and improve the uniformity of the microstructure; S5: The bar stock is final rolled into shape by the sizing and reducing mill, or an intermediate billet is provided for the wire rod path; the sizing and reducing mill is equipped with a path switching device, which can divert the rolled stock to the bar stock path or the wire rod path according to production needs; for the bar stock path, the rolled stock that needs to be water-cooled is uniformly cooled by water cooling and then collected by coiler I; for the wire rod path, the rolled stock is sequentially passed through the modular mill for multi-pass small deformation finishing rolling, the wire rod sizing and reducing mill for final rolling and shaping, and the cooling bed for rapid cooling to regulate the microstructure and properties, and finally collected by coiler II.

[0011] The temperature fluctuation of the rolled piece at the end of the entire rolling process is controlled within the range of -70°C to +30°C. According to the process requirements, the metal should be cooled to below 300°C in water cooling within no more than 20 seconds.

[0012] Application of a precision continuous rolling line method for titanium alloy bars and wires, specifically applicable to the precision rolling of Ti-6Al-4V grade titanium alloy bars and wires.

[0013] The technical advantages of this invention are as follows: 1. By applying two-roll / three-roll / four-roll reducing and sizing mills and controlling the temperature throughout the entire process, the dimensional accuracy of the products is significantly improved, tolerance control is strict, and the roundness is excellent; 2. The mixed roller system configuration combined with precise temperature control effectively improves the uniformity of deformation, avoids coarse grains and crack defects in the core, and obtains bar and wire products with uniform microstructure and properties; 3. By switching production paths, this invention can flexibly produce bars and wires of different specifications on the same production line, adapting to the market demand for multiple varieties and small batches.

[0014] The following will provide further explanation in conjunction with the accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a precision continuous rolling line for titanium alloy bars and wires according to the present invention.

[0016] Figure 2 This is a temperature distribution diagram of the head, middle and tail of the rolled bar and wire blank surface and core of the present invention.

[0017] Figure 3 This is a temperature distribution diagram of the head, middle and tail of the rolled surface and core of the bar and wire rod of the present invention.

[0018] Figure 4 This is a temperature distribution diagram of the rolled surface and core of the bar and wire rod of the present invention, as well as the head, middle and tail of the rolled piece.

[0019] Figure 5 This is a temperature distribution diagram of the surface and core of the finished bar and wire rod of the present invention, as well as the head, middle and tail of the rolled piece.

[0020] Reference numerals in the attached figures: 1-Heating furnace; 2-Blanking mill; 3-Online reheating furnace; 4-Two-roll short stress mill; 5-Sizing and reducing mill unit; 6-Water cooling; 7-Coiler I; 8-Modular mill; 9-Wire rod sizing and reducing mill unit; 10-Cooling bed; 11-Coiler II. Detailed Implementation

[0021] Example 1 like Figure 1 As shown, a precision continuous rolling line for titanium alloy bars and wires includes a heating furnace 1, a billet mill 2, an online reheating furnace 3, a two-roll short-stress mill 4, and a sizing mill group 5 arranged sequentially along the same axis. A bar path rolling line and a wire path rolling line are respectively arranged behind the sizing mill group 5. The bar path rolling line includes a water cooler 6 and a coiler I 7 arranged sequentially along the same axis. The wire path rolling line includes a water cooler 6, a modular mill 8, a wire sizing mill group 9, a cooling bed 10, and a coiler II 11 arranged sequentially along the same axis.

[0022] In this invention, the titanium alloy billet is heated to a set temperature in a heating furnace 1, and the core-to-surface temperature difference of the billet cross-section is controlled to be less than 10°C. The heated billet is then initially rolled using a roughing mill 2 to form a rough-rolled billet. The rolled piece is then reheated and kept warm in an online reheating furnace 3 to maintain its temperature within the suitable deformation range of the titanium alloy. The rolled piece is further rolled using a two-roll short-stress mill 4 to reduce the cross-section and improve the uniformity of the microstructure. Finally, the bar is finished rolled using a sizing mill 5. The rolling mill 5 is equipped with a path switching device after the forming mill, which can divert the rolled piece to the bar or wire path according to production needs. For the bar path, the rolled piece requiring water cooling is uniformly cooled by the water cooling 6 and then collected by the coiler I 7. For the wire path, the rolled piece sequentially passes through the modular mill 8 for multi-pass small deformation finishing rolling, the wire reduction and sizing mill 9 for final rolling and shaping, and the cooling bed 10 for rapid cooling to regulate the microstructure and properties, and is finally collected by the coiler II 11. The temperature fluctuation of the rolled piece at the end of the entire rolling process is controlled within the range of -70℃ to +30℃. The water cooling 6 and the cooling bed 10 independently and automatically adjust the spray cooling intensity according to the temperature feedback. The present invention combines a mixed roller system with precise temperature control, which effectively improves the uniformity of deformation, avoids coarse grains and crack defects in the core, and obtains bar and wire products with uniform microstructure and properties. At the same time, the present invention can flexibly produce bars and wires of different specifications on the same production line through path switching, so as to meet the market demand for multiple varieties and small batches.

[0023] Example 2 Based on Embodiment 1, in this embodiment, preferably, the heating furnace 1 is a multi-zone gas heating furnace or a resistance heating furnace, or a combination of a gas heating furnace, a resistance heating furnace and an induction heating furnace.

[0024] When this invention is used, the heating furnace 1 is a multi-zone gas heating furnace or a resistance heating furnace, or a combination of a gas heating furnace, a resistance heating furnace and an induction heating furnace, to heat the titanium alloy billet to a suitable deformation temperature range, and to ensure that the temperature distribution of the billet cross-section is uniform during the heating process.

[0025] Example 3 Based on Example 1 or Example 3, in this example, preferably, the billet mill 2 is a reciprocating horizontally movable rolling mill, a three-roll Lauter rolling mill, a transverse rolling mill, or a multi-stand two-roll rolling mill.

[0026] When this invention is used, the billet mill 2 is a reciprocating horizontally movable rolling mill, a three-roll Lauter rolling mill, a transverse rolling mill, or a multi-stand two-roll rolling mill, used to complete the initial deformation of the billet.

[0027] Example 4 Based on Example 1 or Example 3, in this example, preferably, the reducing sizing mill 5 is a high-rigidity two-roll reducing sizing mill, a high-rigidity three-roll reducing sizing mill, or a high-rigidity four-roll reducing sizing mill.

[0028] When this invention is used, the reducing and sizing rolling mill 5 is a two-roll mill, a three-roll mill, or a four-roll mill, used to realize the finished product output of bars and the feeding of wire rods.

[0029] Example 5 Based on Example 1 or Example 4, in this example, preferably, temperature monitoring modules are installed at the inlet and outlet of the billet mill 2, the two-roll short stress mill 4, the sizing mill group 5 and the modular mill 8. The temperature monitoring modules use a combination of infrared thermometry and thermocouples to collect temperature distribution data of the head, middle and tail of the rolled piece in real time.

[0030] When using this invention, temperature monitoring modules are respectively installed at the inlet and outlet of the billet mill 2, the two-roll short stress mill 4, the sizing mill group 5, and the modular mill 8 to collect the temperature distribution of the head, middle, and tail of the rolled piece in real time, so as to achieve better temperature control.

[0031] Example 6 A precision continuous rolling line method for titanium alloy bars and wires, using a precision continuous rolling line for titanium alloy bars and wires as described above, includes the following steps: S1: Heat the titanium alloy billet to the set temperature through heating furnace 1, and control the temperature difference between the core and surface of the billet cross section to be less than 10℃; S2: The heated billet is initially rolled by the billet mill 2 to form a rough rolled billet; S3: The rolled piece after billet opening is reheated and kept warm using an online reheating furnace 3 to maintain its temperature within the appropriate deformation range of the titanium alloy. S4: The workpiece is further rolled using a two-roll short-stress mill 4 to reduce the cross-section and improve the uniformity of the microstructure; S5: The bar stock is final rolled into shape by the reducing and sizing mill 5, or an intermediate billet is provided for the wire rod path; the reducing and sizing mill 5 is equipped with a path switching device, which can divert the rolled stock to the bar stock path or the wire rod path according to production needs; for the bar stock path, the rolled stock that needs to be water-cooled is uniformly cooled by the water cooler 6 and then collected by the coiler I 7; for the wire rod path, the rolled stock is sequentially passed through the modular mill 8 for multi-pass small deformation finishing rolling, the wire rod reducing and sizing mill 9 for final rolling and shaping, the cooling bed 10 for rapid cooling to regulate the microstructure and properties, and finally collected by the coiler II 11.

[0032] The temperature fluctuation of the rolled piece at the end of the entire rolling process is controlled within the range of -70°C to +30°C. According to the process requirements, the metal in the water cooler 6 should be cooled to below 300°C within a time of no more than 20 seconds.

[0033] Example 7 An application of a precision continuous rolling line method for titanium alloy bars and wires is described. Using a precision continuous rolling line for titanium alloy bars and wires as described in Example 1, and a precision continuous rolling line method for titanium alloy bars and wires as described in Example 6, Ti-6Al-4V titanium alloy bars and wires are precision rolled. This example uses Ti-6Al-4V (TC4) titanium alloy as an example, rolling it from a Φ155mm round billet to a Φ5.5mm finished wire. The temperature distribution of the surface and core of the bar / wire during the processing is as follows: Figures 2-5 As shown, the specific process is as follows: Heating: The Ti-6Al-4V billet is fed into heating furnace 1 and heated to 940℃ using multi-zone temperature control technology, while ensuring that the core-surface temperature difference of the billet cross section is less than 10℃; Billet rolling: The billet is rolled from Φ155mm to Φ58.7mm in 13 passes using billet rolling mill 2, with an average rolling speed of 2 m / s. Reheating: After the billet is rolled, it enters the online reheating furnace 3 and is kept warm by medium frequency induction heating to prevent excessive temperature drop; Medium Rolling Mill 1: The workpiece is rolled in 4 passes using a two-roll short stress mill 4, from Φ58.7mm to Φ42.73mm, with a bite speed of 0.27 m / s during rolling; Intermediate Rolling and Reduction Sizing: The bar continues to pass through an 8-pass intermediate rolling mill and a 4-pass three-roll / four-roll reduction sizing mill 5, rolling the bar from Φ42.73mm to Φ13.5mm. This stage is crucial for ensuring the bar's precision; the bite speed during the reduction sizing mill is 1.058 m / s. Path switching and finishing: The rolled piece after sizing and reduction enters the wire rod path through the path switching device, and is successively rolled through the modular mill 8 and the wire rod sizing and reduction unit 9 for a total of 10 passes of finishing rolling, from Φ13.5mm to the final finished product Φ5.5mm. The bite speed during finishing rolling is 2.39 m / s. Cooling and Collection: The finished wire rod enters the coiler II11 for collection and coiling. After coiling, it is cooled by water to fix its fine grain structure and mechanical properties.

[0034] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A precision continuous rolling line for titanium alloy bars and wires, characterized in that: The system includes a heating furnace (1), a billet mill (2), an online reheating furnace (3), a two-roll short stress mill (4), and a sizing mill group (5) arranged sequentially along the same axis. Behind the sizing mill group (5) are a bar path rolling line and a wire path rolling line. The bar path rolling line includes a water cooler (6) and a coiler I (7) arranged sequentially along the same axis. The wire path rolling line includes a water cooler (6), a modular mill (8), a wire sizing mill group (9), a cooling bed (10), and a coiler II (11) arranged sequentially along the same axis.

2. The precision continuous rolling line for titanium alloy bars and wires according to claim 1, characterized in that: The heating furnace (1) is a multi-zone gas heating furnace or a resistance heating furnace, or a combination of a gas heating furnace, a resistance heating furnace and an induction heating furnace.

3. The precision continuous rolling line for titanium alloy bars and wires according to claim 1, characterized in that: The billet mill (2) is a reciprocating horizontally movable rolling mill, a three-roll Lauter type rolling mill, a transverse rolling mill, or a multi-stand two-roll rolling mill.

4. The precision continuous rolling line for titanium alloy bars and wires according to claim 1, characterized in that: The reducing sizing mill (5) is a high-rigidity two-roll reducing sizing mill, a high-rigidity three-roll reducing sizing mill, or a high-rigidity four-roll reducing sizing mill.

5. The precision continuous rolling line for titanium alloy bars and wires according to claim 1, characterized in that: Temperature monitoring modules are installed at the inlet and outlet of the billet mill (2), the two-roll short stress mill (4), the sizing mill group (5) and the modular mill (8). The temperature monitoring modules use a combination of infrared thermometry and thermocouples to collect temperature distribution data of the head, middle and tail of the rolled piece in real time.

6. A method for a precision continuous rolling line for titanium alloy bars and wires, using the precision continuous rolling line for titanium alloy bars and wires as described in claim 1, characterized in that: Includes the following steps: S1: Heat the titanium alloy billet to the set temperature through a heating furnace (1) and control the temperature difference between the core and surface of the billet cross section to be less than 10℃; S2: The heated billet is initially rolled by the billet mill (2) to form a rough rolled billet; S3: Use an online reheating furnace (3) to reheat and keep the rolled piece after billet opening, so that its temperature is maintained in the appropriate deformation range of titanium alloy; S4: The workpiece is further rolled using a two-roll short stress mill (4) to reduce the cross-section and improve the uniformity of the microstructure; S5: The bar is rolled into shape by the sizing mill (5) or an intermediate billet is provided for the wire rod path; the sizing mill (5) is equipped with a path switching device, which can divert the rolled parts to the bar or wire rod path according to production needs; for the bar path, the rolled parts that need to be water-cooled are uniformly cooled by water cooling (6) and then collected by coiler I (7); for the wire rod path, the rolled parts are sequentially rolled by the modular mill (8) with multiple passes of small deformation, the wire rod sizing mill (9) is rolled into shape, the cooling bed (10) is rapidly cooled to regulate the microstructure and properties, and finally collected by coiler II (11).

7. The method for a precision continuous rolling line for titanium alloy bars and wires according to claim 6, characterized in that: The temperature fluctuation of the rolled piece at the end of the entire rolling process is controlled within the range of -70°C to +30°C. According to the process requirements, the metal should be cooled to below 300°C in the water cooling (6) within a time of no more than 20 seconds.

8. An application of a precision continuous rolling line method for titanium alloy bars and wires, using the precision continuous rolling line method for titanium alloy bars and wires as described in claim 6, characterized in that: The method is specifically applicable to the precision rolling of Ti-6Al-4V grade titanium alloy bars and wires.

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