A method for fine-graining titanium alloy tube blanks for spinning

Abstract

This invention relates to the field of fine grain processing technology and discloses a fine grain processing method for titanium alloy tube blanks for spinning, including the following specific process steps: S1 Precise blank selection and pretreatment: Select titanium alloy ingots with low impurities and uniform composition, and deeply remove surface oxide scale and inclusions through mechanical grinding and pickling to ensure the purity of the blank; S2 Intelligent control of multi-pass hot forging: Introduce an intelligent temperature control system to monitor and precisely control the furnace temperature in real time to ensure that the tube blank is quickly transferred to the forging equipment when heated to 1000°C; S3 High-efficiency channel extrusion synergistic processing: Adopt advanced equipment integrating heating and extrusion, and seamlessly connect the extrusion process of the tube blank under precise heat preservation at 925°C; The die rotation angle is optimized to 105°, and with the parameter setting of extrusion ratio 5, the metal flows through the channel and is subjected to uniform and high-strength shear force; S4 Ultrasonic-rolling integrated processing; S5 Precise cyclic heat treatment strengthening.

Description

Technical Field

[0001] This invention relates to the field of grain refinement technology, specifically a grain refinement process for a titanium alloy tube blank used in spinning. Background Technology

[0002] With the rapid development of cutting-edge fields such as aerospace, high-end chemicals, and marine equipment, the demand for high-performance titanium alloy tubes has surged. Traditional titanium alloy tube blank processing technology has many limitations: ordinary annealing cannot completely eliminate residual stress in the ingot, making subsequent processing prone to cracking and deformation; the deformation amount during hot forging is poorly controlled, often resulting in uneven grain size and large fluctuations in the mechanical properties of the tube; conventional extrusion cannot ensure uniform stress on the metal, resulting in poor refining effect; rolling is prone to surface defects, reducing the yield; and the overall process has poor continuity and low production efficiency, making it difficult to meet the stringent requirements of high-precision and high-performance materials in high-end manufacturing industries, making industrial upgrading imminent. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a method for refining the grain size of titanium alloy tube blanks for spinning. This method offers advantages such as improved grain refinement, ultra-high dimensional accuracy, and surface quality. It solves the problems of conventional extrusion, which fails to ensure uniform stress distribution on the metal and results in poor grain refinement; rolling, which is prone to surface defects and reduces yield; and the overall process lacks continuity and has low production efficiency, making it difficult to meet the high precision requirements of high-end manufacturing industries.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the present invention provides the following technical solution: a fine-graining processing method for titanium alloy tube blanks for spinning, comprising the following specific process steps, S1 Precise blank selection and pretreatment: carefully select titanium alloy ingots with low impurities and uniform composition, and deeply remove surface oxide scale and inclusions through mechanical grinding and acid pickling composite means to ensure the purity of the blank;

[0007] S2 Intelligent Control Multi-Pass Hot Forging: Introducing an intelligent temperature control system to monitor and precisely control the heating furnace temperature in real time, ensuring that the billet is quickly transferred to the forging equipment when heated to 1000°C;

[0008] S3 High-Efficiency Channel Extrusion Synergistic Process: Utilizing advanced equipment that integrates heating and extrusion, the billet seamlessly connects to the extrusion process under precise temperature maintenance at 925°C; the die rotation angle is optimized to 105°, and with the parameter setting of an extrusion ratio of 5, the metal flows through the channel and is subjected to uniform, high-intensity shear force;

[0009] S4 Ultrasonic Rolling Integrated Processing: Upgraded ultrasonic vibration and rolling equipment linkage system to achieve stable output of 25kHz frequency and 4kW power, ensuring precise synchronization of ultrasonic vibration with rolling action;

[0010] S5 Precision Cyclic Heat Treatment Enhancement: Relying on the intelligent heat treatment production line, it precisely executes the process of "first holding at 800°C for 1.2 hours, then air cooling, then holding at 650°C for 2.5 hours, and then slow cooling with the furnace".

[0011] Preferably, the S1 precise billet selection and pretreatment involves cutting the billet into precisely sized tubes and placing them in a high-precision vacuum annealing furnace for constant-temperature annealing at 850°C for 2.5 hours. This precise temperature control eliminates residual stress and ensures a regular internal crystal lattice structure in the billet.

[0012] Preferably, the S2 intelligent control multi-pass hot forging: the first forging is set with an 18% deformation amount according to the characteristics of the billet, and then the deformation amount is finely adjusted to 12%-15% in each pass with the help of big data analysis, and the cumulative deformation amount is stable at 65%. The whole process follows the principle of "less impact and more forging", so that the grains are fully broken and uniformly refined under multiple small impacts, and efficient dynamic recrystallization is stimulated.

[0013] Preferably, the S3 high-efficiency channel extrusion synergistic treatment involves introducing high-pressure inert gas to enhance metal fluidity, promote full sliding and rotation of grain boundaries, refine grains to below 8μm, and simultaneously improve the density of the microstructure.

[0014] Preferably, the S4 ultrasonic-rolling integrated processing involves vibration waves propagating uniformly within the metal, forming a coupling effect with the rolling stress, effectively reducing deformation resistance by up to 30%, accelerating dislocation annihilation, significantly reducing surface microcracks, and improving the surface smoothness of the pipe.

[0015] Preferably, the S5 precision cyclic heat treatment strengthening utilizes real-time collected temperature and time data for feedback adjustment, fully leverages phase transformation laws, induces the precipitation of fine crystal nuclei, stabilizes and refines the grains, and comprehensively optimizes the strength, toughness, and corrosion resistance of the titanium alloy tube blank, meeting the stringent requirements of high-end spinning processes.

[0016] (III) Beneficial Effects

[0017] Compared with the prior art, the present invention provides a method for refining the grain size of titanium alloy tube blanks for spinning, which has the following advantages:

[0018] 1. The fine grain refinement method for spinning titanium alloy tube blanks has an excellent grain refinement effect: through precise and coordinated processing in multiple stages, the grain size of the titanium alloy tube blank is stably controlled below 8μm. The fine and uniform grain structure significantly improves the strength and toughness of the material, with yield strength increased by 20%-30% and elongation increased by 15%-20%, laying a solid foundation for the stable service of the tube under complex working conditions.

[0019] 2. The fine-graining processing method for titanium alloy tube blanks used in spinning can achieve ultra-high dimensional accuracy and surface quality: the entire process, including blank pretreatment and ultrasonic-rolling integration, is fully controlled, making the tube blank diameter tolerance accurate to ±0.1mm and the surface roughness Ra as low as below 0.8μm, which greatly reduces the subsequent spinning processing allowance, lowers costs, and meets the requirements of precision manufacturing.

[0020] 3. The fine-graining processing method for titanium alloy tube blanks used in spinning significantly improves processing efficiency: intelligent control is implemented throughout the entire process, and each link is seamlessly connected. The production cycle is shortened by 30% - 40% compared with the traditional process, which can efficiently meet the delivery of batch orders and enhance the market competitiveness of enterprises; the idle and debugging time of equipment is greatly reduced, and the energy utilization rate is increased by 25% - 35%.

[0021] 4. The fine-graining processing method for titanium alloy tube blanks used in this spinning process produces finished products with reliable performance stability: precise cyclic heat treatment stabilizes the microstructure, enhances the corrosion resistance of the tube by 30%-40%, and significantly improves its high-temperature oxidation resistance; the mechanical properties fluctuate little under complex stress and extreme environments, and the product defect rate is controlled within 2%, ensuring the safe operation of high-end equipment. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention provides a technical solution, specifically a fine-graining processing method for titanium alloy tube blanks for spinning, including the following specific process steps: S1 Precise blank selection and pretreatment: Select titanium alloy ingots with low impurities and uniform composition, and deeply remove surface oxide scale and inclusions through a combination of mechanical grinding, pickling and other means to ensure the purity of the blank;

[0024] Among them, after being cut into tube blanks of precise dimensions, they are placed in a high-precision vacuum annealing furnace and annealed at a constant temperature of 850°C for 2.5 hours. Precise temperature control eliminates residual stress, makes the internal lattice structure of the blank regular, greatly improves the plastic deformation ability, and lays a good foundation for subsequent processing.

[0025] S2 Intelligent Control Multi-Pass Hot Forging: Introducing an intelligent temperature control system to monitor and precisely control the heating furnace temperature in real time, ensuring that the billet is quickly transferred to the forging equipment when heated to 1000°C;

[0026] The first forging process involves an 18% deformation amount based on the billet characteristics. Subsequent forgings utilize big data analysis to finely adjust the deformation amount to 12%-15% for each pass, resulting in a stable cumulative deformation amount of 65%. The entire process follows the principle of "few impacts and multiple forgings," allowing the grains to be fully broken and uniformly refined under multiple small impacts, thereby stimulating efficient dynamic recrystallization.

[0027] S3 High-Efficiency Equal Channel Extrusion Co-processing: Utilizing advanced equipment that integrates heating and extrusion, the billet seamlessly connects to the extrusion process under precise temperature maintenance at 925°C; the die rotation angle is optimized to 105°, and with the parameter setting of an extrusion ratio of 5, the metal flows through the channel and is subjected to uniform, high-strength shear force;

[0028] Based on this, high-pressure inert gas is introduced to enhance metal fluidity, promote grain boundary slippage and rotation, refine grains to below 8μm, and simultaneously improve the density of the microstructure.

[0029] S4 Ultrasonic Rolling Integrated Processing: Upgraded ultrasonic vibration and rolling equipment linkage system to achieve stable output of 25kHz frequency and 4kW power, ensuring precise synchronization of ultrasonic vibration with rolling action;

[0030] Among them, the vibration wave propagates uniformly inside the metal and forms a coupling effect with the rolling stress, which effectively reduces the deformation resistance by up to 30%, accelerates the annihilation of dislocations, significantly reduces surface microcracks, and improves the surface smoothness of the pipe.

[0031] S5 Precision Cyclic Heat Treatment Enhancement: Relying on the intelligent heat treatment production line, it precisely executes the process of "first holding at 800°C for 1.2 hours, then air cooling, then holding at 650°C for 2.5 hours, and then slow cooling in the furnace";

[0032] Among them, by using real-time collected temperature and time data for feedback adjustment, and making full use of the phase transformation law, fine crystal nuclei are induced to precipitate, and the effect of stabilizing and refining grains is achieved. This comprehensively optimizes the strength, toughness and corrosion resistance of titanium alloy tube blanks, meeting the stringent requirements of high-end spinning processes.

[0033] Furthermore, the method exhibits remarkable grain refinement: through precise and coordinated processing across multiple stages, the grain size of the titanium alloy tube blank is stably controlled below 8μm. The fine and uniform grain structure significantly enhances the material's strength and toughness, increasing yield strength by 20%-30% and elongation by 15%-20%, thus laying a solid foundation for the stable service of the tube under complex working conditions.

[0034] Furthermore, this method can achieve ultra-high dimensional accuracy and surface quality: the entire process, including billet pretreatment and ultrasonic-rolling integration, is fully controlled, making the billet diameter tolerance accurate to ±0.1mm and the surface roughness Ra as low as below 0.8μm, which greatly reduces the subsequent spinning machining allowance, lowers costs, and meets the requirements of precision manufacturing.

[0035] Furthermore, this method significantly improves processing efficiency: intelligent control is implemented throughout the entire process, with seamless connection between each link, shortening the production cycle by 30% - 40% compared to traditional processes, efficiently meeting the delivery of batch orders, and enhancing the company's market competitiveness; equipment idle time and debugging time are greatly reduced, and energy utilization is increased by 25% - 35%.

[0036] Furthermore, the finished product produced by this method possesses reliable performance stability: precise cyclic heat treatment stabilizes the microstructure, increasing the corrosion resistance of the pipe by 30%-40%, and significantly improving its high-temperature oxidation resistance; mechanical properties fluctuate little under complex stress and extreme environments, and the product defect rate is controlled within 2%, ensuring the safe operation of high-end equipment. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for refining the grain size of a titanium alloy tube blank for spinning, characterized in that: The specific process steps include the following: S1 Precision billet selection and pretreatment: Select titanium alloy ingots with low impurities and uniform composition, and use mechanical grinding and pickling to deeply remove surface oxide scale and inclusions to ensure the purity of the billet; S2 Intelligent Control Multi-Pass Hot Forging: Introducing an intelligent temperature control system to monitor and precisely control the furnace temperature in real time, ensuring that the billet is quickly transferred to the forging equipment when heated to 1000°C; S3 High-Efficiency Channel Extrusion Synergistic Processing: Utilizing advanced equipment integrating heating and extrusion, the billet seamlessly connects to the extrusion process under precise temperature maintenance at 925°C; the die rotation angle is optimized to 105°, and with the parameter setting of extrusion ratio 5, the metal flows through the channel and is subjected to uniform, high-strength shear force; S4 Ultrasonic Rolling Integrated Processing: Upgraded ultrasonic vibration and rolling equipment linkage system to achieve stable output of 25kHz frequency and 4kW power, ensuring precise synchronization of ultrasonic vibration with rolling action; S5 Precision Cyclic Heat Treatment Enhancement: Relying on the intelligent heat treatment production line, it precisely executes the process of "first holding at 800°C for 1.2 hours, then air cooling, then holding at 650°C for 2.5 hours, and then slow cooling with the furnace".

2. The method for refining the grain size of a titanium alloy tube blank for spinning according to claim 1, characterized in that: The S1 precision billet selection and pretreatment: After being cut into tube blanks of precise dimensions, the blanks are placed in a high-precision vacuum annealing furnace and annealed at a constant temperature of 850°C for 2.5 hours. Precise temperature control eliminates residual stress and makes the internal lattice structure of the billet regular.

3. The method for refining the grain size of a titanium alloy tube blank for spinning according to claim 1, characterized in that: The S2 intelligent control multi-pass hot forging: the first forging is set with an 18% deformation amount according to the characteristics of the billet. Subsequently, with the help of big data analysis, the deformation amount is finely adjusted to 12%-15% for each pass, and the cumulative deformation amount is stable at 65%. The whole process follows the principle of "less impact and more forging", so that the grains are fully broken and uniformly refined under multiple small impacts, and efficient dynamic recrystallization is stimulated.

4. The method for refining the grain size of a titanium alloy tube blank for spinning according to claim 1, characterized in that: The S3 high-efficiency channel extrusion synergistic treatment: On this basis, high-pressure inert gas is introduced to enhance metal fluidity, promote grain boundary sliding and rotation, refine grains to below 8μm, and simultaneously improve the density of the microstructure.

5. The method for refining the grain size of a titanium alloy tube blank for spinning according to claim 1, characterized in that: The S4 ultrasonic-rolling integrated processing: the vibration wave propagates uniformly inside the metal, forming a coupling effect with the rolling stress, effectively reducing deformation resistance by up to 30%, accelerating dislocation annihilation, significantly reducing surface microcracks, and improving the surface smoothness of the pipe.

6. The method for refining the grain size of a titanium alloy tube blank for spinning according to claim 1, characterized in that: The S5 precision cyclic heat treatment strengthening method utilizes real-time collected temperature and time data feedback adjustment, fully leverages phase transformation laws, induces the precipitation of fine crystal nuclei, stabilizes and refines the grains, and comprehensively optimizes the strength, toughness, and corrosion resistance of titanium alloy tube blanks, meeting the stringent requirements of high-end spinning processes.