Low cost small size titanium alloy bar forging method

Abstract

The application provides a low-cost small-size titanium alloy bar forging method, and aims at the production characteristics of titanium alloy bars. The method realizes low-cost continuous forging of titanium alloy bars with a diameter of less than 100 mm by using two numerical control electro-hydraulic hammers and an on-line heating mode. The method reduces the production equipment investment, reduces the forging fire times, improves the yield, reduces the production cost, and selects two numerical control electro-hydraulic hammers and an on-line induction heater device, which reduces the equipment investment by more than 30%. Through the series connection design of the numerical control electro-hydraulic hammer with high forging frequency and the on-line heating device, the continuous forging is formed. The application reduces the temperature drop in the forging process, improves the forging efficiency, thereby reducing the forging fire times and the energy consumption. The application reduces the forging cracks caused by the temperature drop of the bar surface, improves the yield, and reduces the production cost.

Description

Technical Field

[0001] This invention relates to the field of titanium alloy forging bar production, and more specifically, to a low-cost, small-size titanium alloy bar forging method. Background Technology

[0002] Titanium alloys, due to their superior properties such as high strength, corrosion resistance, and lightweight, are widely used in aerospace, medical devices, and high-end equipment manufacturing. Among these, small-diameter titanium alloy bars (less than 100mm in diameter) are used as raw materials for key structural components, and market demand continues to grow. Currently, the industry mainly relies on free forging processes for the production of small-diameter titanium alloy bars, with high-speed forging mills as the core production equipment. However, this production model suffers from significant technical bottlenecks and cost drawbacks. First, the inherent material properties of titanium alloys limit their forging process window and deformation temperature range. Furthermore, the billet cools rapidly during forging, especially for small bars with diameters under 100mm, where the surface area to volume ratio is relatively large, leading to even faster heat loss. This necessitates increasing the number of forging passes in traditional processes to ensure sufficient billet deformation. This not only prolongs the production cycle and reduces efficiency but also significantly increases energy costs—the multiple heating and forging processes result in substantial energy waste, with energy consumption per unit product exceeding that of conventional metal forging by more than 30%.

[0003] Secondly, the investment cost of high-speed forging machines used in traditional processes is high. The price of a single high-speed forging machine used to produce small-sized titanium alloy bars with a diameter of less than 100mm is generally more than 6 million yuan. The high cost of equipment purchase raises the entry threshold and production cost for enterprises, restricts the participation of small and medium-sized enterprises, and also leads to the overall capacity expansion of the industry being limited.

[0004] Furthermore, due to uneven temperature drop in the billet during forging, the surface temperature decreases faster than the core temperature, easily leading to thermal stress and forging cracks, resulting in a reduced yield. Statistics show that the yield of small-diameter titanium alloy bars produced by traditional free forging processes is only below 75%. The generation of defective products further increases raw material waste and production costs, failing to meet the industry's demand for efficient and low-cost production.

[0005] In summary, existing forging processes for small-diameter titanium alloy bars suffer from problems such as high equipment investment, numerous forging passes, high energy consumption, and low yield. An innovative production method is needed to overcome these technical bottlenecks and achieve low-cost, high-efficiency, and high-quality production. Therefore, a low-cost forging method for small-diameter titanium alloy bars is proposed. Summary of the Invention

[0006] The purpose of this invention is to address the problems of high equipment investment, numerous forging passes, drastic temperature drop during billet forging, high energy consumption, easy surface cracking of billets, and insufficient yield associated with existing forging processes for small-diameter titanium alloy bars that rely on high-speed forging machines. Taking into account the narrow deformation temperature range of titanium alloys and the rapid heat dissipation of small-diameter bars, this invention provides a low-cost forging method for small-diameter titanium alloy bars. This invention employs a process mode of continuous forging with two CNC electro-hydraulic hammers in series, combined with intermediate online induction heating. This effectively alleviates the problem of rapid billet cooling during forging, reduces repeated heating processes and forging passes, lowers the overall equipment investment and energy consumption per piece, balances the billet temperature field to suppress forging cracks, improves the deformation capacity per forging pass and the yield of finished products, reduces enterprise production entry costs, and achieves efficient, low-cost, and high-yield continuous forging of small-diameter titanium alloy bars ranging from 15mm to 100mm.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: a low-cost, small-diameter titanium alloy bar forging method, which employs two CNC electro-hydraulic hammers connected in series to form a continuous forging system, and cooperates with an online induction heating device to forge titanium alloy bars with a diameter of less than 100mm. The continuous forging system and the heating device work together to reduce the number of forging passes and lower production costs.

[0008] As a preferred technical solution of the present invention, the forging frequency of the CNC electro-hydraulic hammer is not less than 120 times / min, and the heat loss during the bar forging process is reduced by high-frequency forging.

[0009] As a preferred technical solution of the present invention, the forging frequency and reduction amount of the two CNC electro-hydraulic hammers can be controlled independently or in conjunction to adapt to the deformation process requirements of bars of different specifications.

[0010] As a preferred technical solution of the present invention, the online induction heating device is set between two CNC electro-hydraulic hammers. The power of the device is adjustable to realize dynamic heating during the forging process.

[0011] As a preferred technical solution of the present invention, during the forging process, the two ends of the titanium alloy billet are clamped by two forging manipulators on the left and right respectively, and the billet is passed through the first CNC electro-hydraulic hammer, the induction heater and the second CNC electro-hydraulic hammer in sequence to achieve stable continuous forging.

[0012] A low-cost, small-diameter titanium alloy bar forging method, the forging process includes the following steps: Step 1: The left manipulator clamps the left end of the titanium alloy billet heated to the forging temperature, passes it through the first CNC electro-hydraulic hammer, the induction heater and the second CNC electro-hydraulic hammer, and the right manipulator clamps the right end of the billet. Step 2: Start the two CNC electro-hydraulic hammers in sequence to begin forging; Step 3: When the temperature drop of the bar stock reaches the set critical temperature, turn on the induction heater for online dynamic reheating.

[0013] As a preferred technical solution of the present invention, the equipment used includes two CNC electro-hydraulic hammers and one online induction heater, with a total investment of no more than 4 million yuan.

[0014] As a preferred technical solution of the present invention, the dynamic heating temperature of the induction heater is set according to the forging temperature range of the bar material to compensate for the temperature drop of the billet during the forging process and eliminate forging cracks caused by surface temperature drop.

[0015] As a preferred technical solution of the present invention, the continuous forging design of two CNC electro-hydraulic hammers improves the deformation rate of each forging pass and reduces energy consumption by more than 30% compared with the traditional high-speed forging process.

[0016] As a preferred technical solution of the present invention, the diameter of the titanium alloy bar ranges from 15mm to 100mm, and the yield is increased by more than 10% compared with the traditional free forging process.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention uses two CNC electro-hydraulic hammers and one online induction heater as core equipment. The total investment of the entire set of equipment does not exceed 4 million yuan. Compared with the fast forging machine used in traditional processes, the equipment investment is reduced, which significantly lowers the initial investment threshold for enterprises. It is especially suitable for the production capacity layout of small and medium-sized production enterprises and enhances the promotion and application value of the technology.

[0018] The CNC electro-hydraulic hammer of this invention can achieve a forging frequency of over 120 times / min, higher than the traditional high-speed forging machine's below 100 times / min. This high-frequency forging effectively reduces heat loss of the billet during the forging process. Furthermore, the continuous forging process formed by two electro-hydraulic hammers connected in series increases the deformation rate per forging pass. Combined with forging parameters that can be independently or in conjunction with the two machines, deformation efficiency is further optimized. In addition, the online induction heating device between the two electro-hydraulic hammers can dynamically compensate for the billet temperature drop, extending the effective forging time per pass. The synergistic effect of these three factors not only shortens the production cycle and improves production efficiency compared to traditional processes, but also reduces energy costs by eliminating multiple heating stages, resulting in lower energy consumption per unit product compared to traditional processes.

[0019] The adjustable power design of the online induction heater in this invention allows for precise heat replenishment based on the forging temperature range of titanium alloy materials. This effectively solves the problem of thermal stress caused by excessively rapid temperature drop on the billet surface in traditional processes, eliminating forging cracks at their source. Actual production verification shows that this invention improves the yield of small-diameter titanium alloy bars, significantly reduces raw material loss compared to traditional processes, lowers production costs due to defective products, and further consolidates the advantages of low-cost production.

[0020] The forging frequency and reduction amount of the two CNC electro-hydraulic hammers of this invention can be independently or in conjunction with the process requirements of titanium alloy bars of different specifications and materials, and with the flexible adjustment of online heating temperature, the process has good adaptability, can meet diverse production needs, and improve the practicality and industry applicability of the technology.

[0021] The production line of this invention has a compact layout. The left and right manipulators work together to achieve stable clamping and conveying of the billet. The forging process is clear and orderly, eliminating the need for complex intermediate transfer links, simplifying production operations, reducing labor costs and the risk of operational errors, and further improving production efficiency and the stability of the production process. Attached Figure Description

[0022] Figure 1 This invention provides a production line layout diagram for a low-cost, small-size titanium alloy bar forging method.

[0023] The image shows: 1. Left manipulator; 2. First CNC electro-hydraulic hammer; 3. Induction heater; 4. Second CNC electro-hydraulic hammer; 5. Right manipulator. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are specific implementations of the present invention and are not limited to all embodiments.

[0025] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] Example 1: A low-cost forging method for small-diameter titanium alloy bars, which uses two CNC electro-hydraulic hammers connected in series to form a continuous forging system, and is equipped with an online induction heating device to forge titanium alloy bars with a diameter of less than 100mm. The continuous forging system and the heating device work together to reduce the number of forging passes and reduce production costs.

[0028] The forging frequency of the CNC electro-hydraulic hammer is no less than 120 times / min, which reduces heat loss during the bar forging process through high-frequency forging.

[0029] The forging frequency and reduction amount of the two CNC electro-hydraulic hammers can be controlled independently or in conjunction to adapt to the deformation process requirements of bars of different specifications.

[0030] An online induction heating device is installed between two CNC electro-hydraulic hammers. The power of this device is adjustable, enabling dynamic heating during the forging process.

[0031] During the forging process, the two ends of the titanium alloy billet are clamped by two forging manipulators on the left and right respectively, and the billet is passed through the first CNC electro-hydraulic hammer 2, the induction heater 3 and the second CNC electro-hydraulic hammer 4 in sequence to achieve stable continuous forging.

[0032] A low-cost, small-diameter titanium alloy bar forging method, the forging process includes the following steps: Step 1: The left manipulator 1 clamps the left end of the titanium alloy billet heated to the forging temperature, passes it through the first CNC electro-hydraulic hammer 2, the induction heater 3 and the second CNC electro-hydraulic hammer 4, and the right manipulator 5 clamps the right end of the billet. Step 2: Start the two CNC electro-hydraulic hammers in sequence to begin forging; Step 3: When the temperature drop of the bar stock reaches the set critical temperature, turn on the induction heater 3 for online dynamic reheating.

[0033] The equipment used includes two CNC electro-hydraulic hammers and one online induction heater. The total investment for the entire set of equipment does not exceed 4 million yuan.

[0034] The dynamic heating temperature of the induction heater 3 is set according to the forging temperature range of the bar material to compensate for the temperature drop of the billet during the forging process and eliminate forging cracks caused by surface temperature drop.

[0035] By using a continuous forging design with two CNC electro-hydraulic hammers, the deformation rate of each forging pass is increased, reducing energy consumption by more than 30% compared to traditional high-speed forging processes.

[0036] The diameter range of titanium alloy bars is 15mm to 100mm, and the yield is more than 10% higher than that of traditional free forging process.

[0037] Working principle: The low-cost, small-size titanium alloy bar forging method of the present invention is based on the material characteristics of titanium alloy, such as narrow deformation temperature window, low thermal conductivity, and rapid temperature drop during forging. By integrating high-frequency CNC electro-hydraulic hammer, continuous forging process and online dynamic heat replenishment technology, it effectively suppresses the temperature drop of billet during forging, extends the effective forging time of a single forging, and thus significantly reduces the total number of forging forgings.

[0038] CNC electro-hydraulic hammers have a high forging frequency of up to 120 times / minute, which is much higher than the traditional high forging machine's ≤100 times / minute. This allows for more deformation to be completed per unit time and reduces heat loss. Two CNC electro-hydraulic hammers are arranged in series and used with the manipulator to achieve continuous reciprocating forging, so that the billet can be deformed in multiple passes by the two hammers after one heating, thereby improving the cumulative deformation rate of a single heating pass. The induction heater 3 is positioned between the two hammers, which can provide precise and dynamic heat replenishment to the middle part or temperature drop area of ​​the billet during the forging process, maintain the overall temperature uniformity of the billet, avoid cracking defects caused by excessive surface cooling, and extend the effective forging window.

[0039] Forging process steps: The left manipulator 1 clamps the left end of the titanium alloy billet heated to the forging temperature, passes it through the first CNC electro-hydraulic hammer 2, the induction heater 3 and the second CNC electro-hydraulic hammer 4, and the right manipulator 5 clamps the right end of the billet. Two CNC electro-hydraulic hammers are started sequentially to begin forging. When the bar stock temperature drops to the set critical temperature, the induction heater 3 is activated for online dynamic reheating. The equipment used includes two CNC electro-hydraulic hammers and one online induction heater 3. The dynamic reheating temperature of the induction heater 3 is set according to the forging temperature range of the bar stock material to compensate for the temperature drop of the billet during forging and eliminate forging cracks caused by surface temperature drop. Through the continuous forging design of two CNC electro-hydraulic hammers, the deformation rate of each forging pass is improved, and energy consumption is reduced by more than 30% compared with the traditional high-speed forging process.

[0040] The diameter range of titanium alloy bars is 15mm to 100mm, and the yield is more than 10% higher than that of traditional free forging process. Through the three-in-one synergistic mechanism of high frequency forging, continuous deformation and online heating, the equipment investment, energy consumption and number of forging cycles are greatly reduced while ensuring the forming quality, so as to achieve low-cost and high-efficiency production of small-sized titanium alloy bars with a diameter of less than 100mm.

[0041] The work process is as follows: Initial heating: Heat the titanium alloy billet to the target forging temperature, maintain the temperature evenly, and then remove it from the furnace; Clamping and positioning: The left manipulator 1 clamps the left end of the billet and passes it through the first CNC electro-hydraulic hammer 2, the intermediate induction heater 3 and the second CNC electro-hydraulic hammer 4 in sequence. The right manipulator 5 simultaneously clamps the right end of the billet to complete the positioning. Start continuous forging: Start #1 and the second CNC electro-hydraulic hammer 4 sequentially according to the preset program to alternately or synchronously upset and draw the billet. The manipulator coordinates the feeding speed and hammering rhythm to ensure that the billet passes through the two hammers continuously; Online heating: During the forging process, the temperature of the billet surface or key parts is monitored in real time. When the temperature drops to the set critical value, the intermediate induction heater 3 is automatically activated to provide local rapid heating to restore the billet to the appropriate forging temperature. Cyclic forging: Repeat steps 3–4 until the target deformation or dimensional requirements are achieved in a single forging operation; End of heating cycle: If the final dimensions are not reached, the billet is returned to the heating furnace for reheating and proceeds to the next heating cycle; otherwise, it proceeds to the subsequent cooling, straightening, and finishing processes.

[0042] The entire process is controlled by a CNC system to achieve coordinated control of the frequency of the electro-hydraulic hammer, the amount of pressing down, the feed speed of the manipulator, and the power of induction heating, ensuring process stability and product quality consistency.

[0043] Example 2: A low-cost, small-diameter titanium alloy bar forging method, producing 80mm TC4 titanium alloy bars in two-fire continuous forging: the raw material is a 150mm×600mm TC4 titanium alloy ingot, which is then free forged to obtain a 110mm round billet. The Φ110mm billet is heated to 1020℃ and held for 90 minutes. After being taken out of the furnace, it is clamped by the left operating machine 1 and sent into the production line. The first CNC electro-hydraulic hammer is started at a frequency of 110 times / min, with a single pressing amount of 8mm for the first round of elongation. Then the billet enters the second CNC electro-hydraulic hammer at a frequency of 115 times / min, with a pressing amount of 7mm for continued deformation. When the temperature in the middle of the billet drops to 910℃, the induction heater 3 with a rated power of 300kW and a frequency of 8kHz automatically starts to rapidly heat the passing area for 2–3 seconds, raising the temperature by about 50℃. After five consecutive drawing passes with two hammers, the billet diameter is reduced to Φ85mm and the length increases to approximately 1200mm, completing the first firing process. The material is returned to the heating furnace and reheated to 1000℃ for a second continuous forging process, ultimately yielding a finished bar stock with a diameter of 80mm and a diameter of 2000mm. The entire process requires only 2 heat treatments, which is 1-2 fewer than the traditional high-speed forging process that usually requires 3-4 heat treatments. The total investment in the equipment is about 3.8 million yuan, which is 36.7% less than the 6 million yuan high-speed forging machine solution.

[0044] Example 3: A low-cost, small-diameter titanium alloy bar forging method, TA15 titanium alloy Φ60mm bar single-fire near-net-shape forming: using Φ100mm TA15 titanium alloy billet, heated to 980℃ α+β two-phase region, held for 60 minutes; The billet is fed into a continuous forging line consisting of two CNC electro-hydraulic hammers, each operating at 120 times / min, and a 200kW induction heater 3 in the middle. The left and right manipulators 5 feed material synchronously at a speed of 0.3 m / s. Hammer #1 first performs 3 upsetting passes with a total compression rate of 15%, and then hammer #2 performs 7 stretching passes. In the forging stage, the surface temperature of the billet drops to 890℃, and the induction heater 3 is started instantly to reheat the Φ70mm transition section to 940℃; The material undergoes continuous deformation from Φ100mm to Φ62mm in a single firing cycle, followed by a finishing and drawing process to Φ60mm, achieving a total deformation rate of 64%. Because online heating effectively suppresses surface cooling cracks, the finished product has no surface defects and the flaw detection pass rate is ≥99%. Compared to the traditional process that requires three firings, this solution achieves near-net-shape forming in a single firing, reducing energy consumption by about 40% and increasing production efficiency by more than 50%.

[0045] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A low-cost, small-diameter titanium alloy bar forging method, characterized in that: Two CNC electro-hydraulic hammers are connected in series to form a continuous forging system, which is equipped with an online induction heating device to forge titanium alloy bars with a diameter of less than 100 mm. The continuous forging system and the heating device work together.

2. The low-cost, small-diameter titanium alloy bar forging method according to claim 1, characterized in that: The forging frequency of the CNC electro-hydraulic hammer is no less than 120 times / min, and the heat loss during the bar forging process is reduced by high-frequency forging.

3. The low-cost, small-diameter titanium alloy bar forging method according to claim 1, characterized in that: The forging frequency and reduction amount of the two CNC electro-hydraulic hammers can be controlled independently or in conjunction to adapt to the deformation process requirements of bars of different specifications.

4. The low-cost, small-diameter titanium alloy bar forging method according to claim 1, characterized in that: The online induction heating device is installed between two CNC electro-hydraulic hammers. The power of the device is adjustable, enabling dynamic heating during the forging process.

5. The low-cost, small-diameter titanium alloy bar forging method according to claim 1, characterized in that: During the forging process, the two ends of the titanium alloy billet are clamped by two forging manipulators on the left and right respectively, and the billet is passed through the first CNC electro-hydraulic hammer (2), the induction heater (3), and the second CNC electro-hydraulic hammer (4) for stable continuous forging.

6. The low-cost, small-diameter titanium alloy bar forging method according to claim 1, characterized in that: The forging process includes the following steps: Step 1: The left manipulator (1) holds the left end of the titanium alloy billet heated to the forging temperature, passes it through the first CNC electro-hydraulic hammer (2), the induction heater (3), and the second CNC electro-hydraulic hammer (4), and the right manipulator (5) holds the right end of the billet. Step 2: Start the two CNC electro-hydraulic hammers in sequence to begin forging; Step 3: When the temperature drop of the bar stock reaches the set critical temperature, turn on the induction heater (3) for online dynamic reheating.

7. The low-cost, small-diameter titanium alloy bar forging method according to claim 1, characterized in that: The equipment used includes two CNC electro-hydraulic hammers and one online induction heater (3).

8. A low-cost, small-diameter titanium alloy bar forging method according to claim 4, characterized in that: The dynamic heating temperature of the induction heater (3) is set according to the forging temperature range of the bar material to compensate for the temperature drop of the billet during the forging process and eliminate forging cracks caused by surface temperature drop.

9. The low-cost, small-diameter titanium alloy bar forging method according to claim 1, characterized in that: By using two CNC electro-hydraulic hammers for continuous forging, the deformation rate of each forging pass is increased.

10. A low-cost, small-diameter titanium alloy bar forging method according to claim 1, characterized in that: The diameter of the titanium alloy rod ranges from 15mm to 100mm.

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